Tire wear, Tire testing & Recommendations.
Wheels, spacers, nitrogen, wet roads, hydroplaning, etc.
...for BMW & other Motorcycles.
PLUS things you never knew about tires!
© Copyright, 2014, R. Fleischer
article #54, section 5
It is difficult to maintain a list of recommended tires, due to changes in what is available; and,
what I have ridden & tested. Up until a couple of years ago, my normal testing was considerably
more vigorous & formal than that of many riders. I am putting on fewer miles these days, and
have been reducing the vigorousness of testing. In the past I had not often included other's
remarks about tires that I had not personally ridden & tested. I now have three people, whose
tire testing mirrors mine close enough. I will include their input now & then. In this article I will
clearly state when I personally have less experience or no experience on a particular tire.
I list some discontinued tires on purpose, for reference & comparison.....some old style tires
are now being re-made, often with updated rubber and possibly construction.
MORE information on wheels is located in:
http://bmwmotorcycletech.info/section6.htm gets heavily into tube & tubeless, on various rims.
http://bmwmotorcycletech.info/tirerepair.htm gets heavily into tire repairs.
Some words of caution, & STRAIGHT TALK:
Some types of tire testing is relatively easy & this is the type MOST TYPICALLY reported
or commented-on (in Lists, Forums, ETC). Frankly, mostly it is JUST OPINION, with
LITTLE REAL FACTS. This type of opinion comes from those who do these things (generally):
You keep your tires inflated properly; you ride like you usually do, on paved roads
(most riders), with mixed speeds, mixed type of curves, mixed type of road roughness,
mixed loading. You write down the odometer reading when you put the tires on &
when you take them off for replacement. Perhaps you always replace tires when the
center of the tread is 1/16" deep. You write the mileage down, subtract, & now you have
YOUR typical mileage for YOUR usage on THAT tire, at YOUR weight, loading & tire
pressure. Yes...this can be useful information. But, in your 'opinions', do you specify
EXACTLY all the facts about riding style (in depth), pressures, loads, types of roads...
& many other things? If you say you are aggressive, just what does that REALLY
MEAN? Would you be able to write a report, that not only gives real testing facts, but
recommendations, honest comparisons against other brands & models, ETC.?
Many are interested, when discussing motorcycle tires, about how well the tire 'sticks to
the road'; & how well it handles various conditions. In a rather large percentage of
instances, no 'standards', only not-very-qualified opinions, are seen in such discussions.
The bald truth (BAD pun!) is that modern tires are vastly better than the tires were when
your Airhead was manufactured (particularly before the nineties), & unless you have
REAL racetrack experience, you are UNLIKELY to out-ride the tire; in fact you are probably
unlikely to actually know how-to...and if you did try, you likely would brown your shorts.
Your Airhead is of limited power, limited braking, & may have suspension aging or
improper setup problems...all of which affect tire life (AND handling!).
VERY serious accidents can occur with something as simple as a tight turn, especially
at speed, especially with a rear tire tread that has been worn more than somewhat (the
center of the tire tread is flattened), when it originally was rounded to some degree.
IF you tried to duplicate my style of testing (particularly when I was younger), & the
testing or at least educated experience from those who ACTUALLY put their tires 'to
the test', perhaps on racetracks, or in serious dirt conditions......you could be asking
for serious trouble.
ASK YOURSELF: Are you REALLY competent at crossing up the steering during sliding?
Does the idea of crossing-up the steering freak-you out? On wet roads? What about
when your beautifully executed carving turn encounters lots of bumps? Sudden
off-banked tight turns? Washboards? Can you truly (be honest!) feel the difference a
FEW pounds of pressure makes? Have racetrack & soft dirt/gravel & wet roads
experience? Are you smooth with the controls (including brakes, clutch & throttle)?
Are you smooth with transitions from any surface or turn direction, etc.? I am NOT so
much questioning you here about YOUR REAL COMPETENCE, as I am questioning
your tire testing methods and abilities....&, in particular, your analysis of YOUR tires.
Tires DO vary considerably, in how they handle, how they wear, & under what types
of conditions (including road surfaces, straights, turns, off-banks, braking in dry
good friction areas versus wet roads....what about deeper water on those roads?
What type of tire do YOU NEED? WHY? What characteristics of/in a tire do you
REALLY need? Be honest with yourself!
PROBABLY quite a few tires will work well for most any type of riding you do. BUT,
you MAY be the type of rider that really IS aggressive, or has special needs. Perhaps
you really do ride off-road, into seriously soft stuff, mud, single track trails, real
Adventure Riding. Perhaps you love carving turns at speed on paved roads. Are
those turns nice sweepers, or really tight twisties on, perhaps, very narrow roads?
What about the FEEL of your tires in very tight twisties, changing directions very quickly?
Perhaps you REALLY use the front brake truly hard. Do you brake in turns? Perhaps
you ARE a real all-weather rider; maybe you use your motorcycle as your primary
transportation, year-round. Riders have different real needs for their tires.
I will try to cover all uses & rider types for specific tires. Since there is so much
interest in tires, I offer a fair amount of information in this article. I will try to separate
anecdotes from facts. I try to separate those whose input comes from racing
experience, from those with road experience. I try to do that in several ways. Keep
in mind that when a very experienced track racer rides a bike on the streets & highways,
his/her expressed viewpoints about their tires tends, often rather strongly, to be a
comparison between how his RACE BIKE handled on a RACETRACK, with REAL
racing tires,.....to what his street bike feels like on street-riding tires. This may/can
have NOTHING MUCH OF VALUE to YOU, the street rider. BUT, his/her input MAY
have very solid value, depending on how his/her street riding is done. In MY
experience, SOME real racers are milder in street riding, than you may think....but, they
ALSO may be VERY aggressive AT TIMES in such as tight twisties. Thus, their input
on tire feel & mileage may be very different from your input, even if you say & ARE,
aggressive in your riding. Do YOU square off your rear tire in your riding?...do you
wear the sides of the tread very noticeably?
How do reports from these various types of riders vary? Why?
Will YOU ever ride in the twisties to the extend and aggressiveness of someone with
a LOT of track experience, particularly on track type racing tires? If YOUR tires
are a type that such expert and aggressive riders like, will YOU like them???
Be very cautious!
Be VERY cautious about who you listen to. ULTIMATE road performance MAY WELL
not be what YOU are going to be REALLY interested in.
I HIGHLY RECOMMEND YOU DO NOT TRY TO DUPLICATE MY PRIOR TESTING
METHODS UNLESS YOU ARE COMPETENT TO DO SO, & ARE WILLING TO TAKE
ON THE RISKS OF DOING SO.
I AM NOT...NOT!!...RESPONSIBLE FOR INCIDENTS & ACCIDENTS!
Most of my testing was done on a variety of Airheads. Some was done on classic
K-bikes. In a few instances, I tested on other folks motorcycles; much more rarely
on other makes of bikes. I also tested on two models of Ninja's...but the results
are NOT shown here, as the handling feel on a Ninja is NOT comparable to a BMW
Airhead, nor a BMW Classic K bike.
1. Some types of tires do/did not work well on some Airhead motorcycles. Radial tires,
quite some time ago, did not generally come in Airhead sizes; particularly for the twin shock
Airheads & early Monoshock Airheads. Most Airheads (just very late models) were never
shod with any type of radial tire. The tires that they came with, & were shod with later, were
more clearly delineated between lower mileage 'stickier' tires & high mileage tires. Tire
characteristics VARIED MORE, IN SOME RESPECTS, THAN TODAY. TIRES BACK THEN
ALSO REQUIRED LOWER TIRE PRESSURES; CONSTRUCTION OF THE TIRE WAS
QUITE DIFFERENT (FOR MANY) THAN TODAY'S TIRES. Now we have special radial tires
for 'classic' motorcycles like our Airheads & the Classic K bikes (K models up to K1200, is
what I mean). Most do well, & even quite excellently. You may like them. You may not
like the prices, or the longevity, or the difference in feel, etc.....particularly if you are not QUITE
aggressive. Non-racers TEND to over-estimate their 'aggressiveness'.
LOWER profile tires (modest, such as 80 section) may not work well (exceptions, particularly
the K bikes), & many simply don't properly fit old Airheads. Generally a "90" profile works
best on all but the last Airheads. SOME 80 profile tires will fit & perform OK on earlier
Airhead bikes. Unless I specifically make such note in this article, assume that I used the
stock tire sizes, or metric equivalents, or close metric equivalents.
2. Frames & suspensions were designed by BMW for a specific feel & handling that BMW desired.
Many seem to have no idea that frame design & construction, suspensions, & MANY other
things, ALL, together, affect how a motorcycle feels, & one word is often used, without specifics:
HANDLING. In common use are such terms as FEEL, TURN-IN, FALL-IN, TWITCHINESS,
QUICKER-Handling, & other words, that you might think mean something very specific.
3. BMW used to issue bulletins with names & models of tires that BMW HAD TESTED
& APPROVED; but that has not been done for Airheads since they were in
production (with some very few exceptions).
4. Here is a link to a rather nerdy article. The article has extensive vector & other diagrams, &
some conclusions about contact forces that may well astonish you. When you read it, keep
in mind what REALLY happens when you are cornering...&..THINK....about the effects of you
changing a tire size....from, an example here, a 90/90 to a 100/90. What REALLY happens
when you go to a larger size tires (larger width). You may be very interested.
5. Many if not mostly all of the tires from the seventies, eighties & nineties, are no longer available,
except for a few, including the classic Continental RB2 and K112, and now some re-incarnations
of Metzeler 'Heritage" tires, etc. Those Continental front tires, unfortunately, follow rain grooves.
Rain-groove-following is a problem with all straight ribbed front tires & some others with irregular
treads. There are tires available now that have only one center rib, usually wider than the old
narrower grooves & are typically better on rain grooves. Tires withOUT center ribs of any sort
generally do not usually follow rain grooves, but there are exceptions; usually the instabilities are
mild. Some folks are very much bothered by the feel of their bike when the tires track rain grooves,
other riders are not bothered, simply accepting the feel. SOME types of bridge gratings can
cause an even more disturbing situation, depending on the types of gratings & can
cause a goodly pucker factor; even increased concern if the gratings are wet from rain.
Not many ride on original type of ribbed front types, and one reason is that they DO, usually
seriously, follow rain grooves, contrary to what is said in some Clymer's publications. Still, you MAY
want to try a set, as they can deliver the classic ride & handling that your bike was designed-for.
These tires generally work best at the originally recommended by BMW tire pressures (label was
under the seat, see your owners manual too), or slightly higher (typically by 2 psi front, 3 psi rear).
I recommend that if you run these classic tires that you inflate to the TWO-UP and/or high speed
pressures shown in the Owners Booklet. These tires give reasonably good mileage before they
wear out. If you have a modified suspension, the classic ride & handling will be modified.
6. I have personally ridden on quite a few modern tires, besides the really old type tires. MOST
modern road type tires offer reasonably good road handling, decent predictability of handling in
various situations, indication to the rider of what the tires are doing AND GOING TO DO; as well
as comfort, load carrying, traction in cold/wet/dry & not unreasonable differences in handling
between moderately wet & dry. One thing usually discussed, MILEAGE (tire wear), SHOULD
NOT the most important characteristic for most riders ...although for some folks, who put on
large mileages, that can be of more importance...so I DO get into recommended tires for mileage.
MANY of today's tires, including re-incarnations of old styles, will have better mileage, than long
ago, even though these modern tires are not being sold as 'high mileage'. That is due to the use
of silica's (sand.....), and different tire compounds in the center & even the sides of the tire.
7. There is a wide difference in how tires FEEL to the rider & also wide differences by models of
BMW motorcycle. Trail & suspension & wheel width differences are only a quite modest portion
of the reasons. MOST ALL modern tires are capable of out-handling the bike & MOST
RIDERS. They stick to the road rather well, even at big lean angles under fairly severe
conditions at speed. That's the truth. BUT, there is another truth: the FEEL can make the
rider THINK the bike is handling Wonderfully...OR...Poorly. When reading tire
comments/reviews, FEEL is NOT well differentiated.
MANY modern tires have profiles, type of rubber, type of design, type of tread, ETC., that give
a "quicker handling" feeling. Many modern tires FEEL to the rider, particularly when starting out
on a new set of tires they have not ridden on before....that they are considerably OVER-inflated,
& might be called SKITTERY. 'Quicker Handling' is often the term used by those riders. Many
riders are timid, particularly on wet roads...but, the tires may feel ...or be described...as quick, or
twitchy, or skittery, etc... on dry roads too, even after thousands of miles on the same tires.
Wet roads tend to create a considerable apprehension for many riders. Many riders did
not experience wet roads much when learning to ride & are slightly to moderately freaked-out by
the idea of riding in rainy conditions. They have hardly ever, maybe some never, ridden on quite
wet roads. These types of riders may especially freak-out on gravel or dirt roads...even at just
the thought of being on gravel roads. I KNOW riders who are NOT going to attend a function,
such as a TechDay, etc., if the driveway is gravel, or too steep, etc. This is not an article about
how to ride bikes, I am just telling the truth about various riders. If a rider is ACTUALLY timid
(hard to find out!), how much weight will you give to this rider's opinions about tires? MAYBE
YOU SHOULD pay attention...you might be like him/her!! The truth is that most motorcyclists
are NOT after racing experiences! Many do NOT want to ride aggressively. MANY are OLDER
& don't like 'taking chances' (which words have variable meanings to riders). Many riders are
simply out for a "Gentleman's ride on Sundays"; or a mild ride to a TechDay or camp-out. It is
true, also, that many like some occasional aggressive fun in twisties. THAT, usually, is NOT at
ALL the same as turn after turn, ETC., on a racetrack, on a race-prepared bike, with racing
WE NEED to consider all riders, in talking about tires. That means I NEED TO, also, in reporting
on tires. I try to analyze tire performance for ALL USERS. The exception is real RACING,
where skills are likely quite high, aggressiveness is a given, special tires are in use, as are
special techniques...such as pre-warming the tires in the pits, wearing sidewalls rapidly, speeds
are high...& quite a few other things. I have not, but very seldom, reported on racing tires. You will
not likely find that information in THIS article.
8. Mileage one gets from tires depends on speed, loading, tire pressure, road condition, style, etc.
Be very cautious about who you listen-to. You may want to ask very detailed questions!
9. Riders want information on tire brands, models, & characteristics; & for conditions they may
never encounter! This is very much like doing discussions over a few beers or around the
campfire, or 'garage racing'. In MANY instances, Rider's viewpoints on their own tires are
NOT substantiated by real testing. I hope to provide REAL information in this article.
10. I have tested tires on both asphalt roads (especially with various types of tar repair stripes,
which also tests suspension stiction); concrete paved roads as well as gravel/hard-pack;
and, occasionally rather soft stuff (yes, on road tires). My testing was, perhaps, unusual.
I did REAL ACTUAL CONTROLLED TESTING. I have racing experience both on/off road,
on 2-wheelers & sidecar rigs. I have available close-by my home some very specific
roads that I have CONSISTENTLY used since 1973 for testing. These offer a wide variety
of surfaces & conditions. I tested in below freezing temperatures, as well as hot Summers.
I made a point of trying to ride when it rains, because it does not rain very much here. I even
tested on somewhat icy roads (!!). When I first moved here I had a R75/5 for good
weather/roads....but I also had a "light weight" (for back then!) dirt bike, shod with knobbies,
that I rode in the snow. It was great fun but physically a lot of exertion. I no longer do that in
the snow (although I still do ride my sidecar rig in the snow....lots of fun!).
11A. "Classic BMW Airhead Handling" is GENERALLY & LIKELY AVAILABLE ONLY with the
original type of tires in original sizes. This is particularly so with the older models that came
with 3.25 x 19 front tires & 4.00 x 18 rear tires. Tires that have the classical ribbed front &
matching rear, with more or less original sidewall stiffness, ETC....that will probably duplicate
the 'original ride'; are such as the Continental's RB2 front & K112 rear tires. Some early
Metzelers have such handling. In order for a close-to-full classical experience ride you
use the same types of tires that were designed to work together as a set. It is possible that
some ChengShin tires will also exhibit the classic feel. Bridgestone has the Accolade tires,
front is ribbed, but I do not have any experience with them. One of the problems
with trying various classic/heritage (or similar) tires is that MOST riders no longer
have the exact same type of original shock absorbers & springs; or, those are not
in good condition; or, other parts of the motorcycle have aged; or, they have made
other changes. Just changing the type or style of handlebars WILL AFFECT the
bike feel. If your bike is in reasonably decent condition & reasonably close to
original specifications, you might really want to try a set of the old tires (which
might well have some changes in them, so you might NEVER REALLY get the
exact original feel as when the bike was brand-new). It REALLY IS worth trying
these tires if you want to experience something close to original feel. If you
don't like the tires, sell them to someone else. I think you may enjoy being a
11B. Up until maybe 8 or 10 years ago, some tire sizes were getting harder to find in proper
INCH sizes. While a number of the old sizes, such as 3.25-19, are available from
several manufacturer's, some were not very commonly available. An particular example
is the 3.25-18 used on the R45 and R65.
HINT: Try: http://www.durotire.com/ ........and click on CLASSIC (or similar word). BUT,
do, FIRST, check into the Heritage line of tires from Metzeler, & the Continental
classic tires, ....and the Bridgestone Accolade.
Many riders no longer use the classic inch sizes. NOW-A-Days, MANY inch-size tires are
available again in various brands/models. MANY are using metric-sizes. But, many are
now trying the newer inch-sized tires too. Several manufacturers now have tires specifically
made & advertised for "Classic Bikes". These tires are really worthwhile looking into.
This advice INcludes the new radial tires designed for our classic bikes.
All these things, including suspension changes, pressure changes, etc., lead to a QUITE
DIFFERENT ride from original stock configuration. Most riders just want a good ride with
good handling & good tire longevity & don't really care about the 'classic' feel & handling.
MANY have a lot of experience on other brands & models of bikes, & may want their
Airhead to FEEL & HANDLE similarly, or 'just better', whatever THAT MEANS TO THEM.
LOTS OF VARIABLES. It is DIFFICULT TO TEST TIRES WITH SO MANY IDEAS, SO
MANY TYPES OF RIDERS, SO MANY TYPES & STYLES OF TIRES. Think seriously
about yourself, your abilities, your actual riding, TRY to KNOW what you like & want, &
if you don't know.... well.... nothing says you cannot try a few different tires.
12. MOST 'modern' tires on the OLDEST Airheads (perhaps to as late as 1985) require
considerably higher pressures than stated on the tag under the seat or in the owner's
manual or in some tire manufacturer's literature. BMW did better by the late eighties onward
...regarding tire pressure recommendations. Failure to inflate to proper higher values will
result in poor handling; the bike may feel like the tires are trying to roll off the rim, etc. When
you DO inflate to a higher value, the tire MIGHT feel skittery, until you are used to the
improved handling. THE TIRE PRESSURE LISTED ON A TIRE SIDEWALL IS NOT THE
RECOMMENDED TIRE PRESSURE. IT IS A MAXIMUM TIRE PRESSURE, BASED ON
WHATEVER STANDARDS THE MANUFACTURER USES FOR THE CARCASS, ETC.
CONSTRUCTION & pressures versus industry classifications. I treat tire pressures a
bit more in-depth in http://bmwmotorcycletech.info/TireRepair.htm in a section near the
bottom of that article. FOR YEARS I have been telling people that the tire pressures
printed in your owners booklet, & in various literature, & particularly so for BMW's
prior-to-1985 models (after which tire pressure recommendations are a more reasonable
but not perfect, in MY opinion), are MUCH TOO LOW....for modern tires.
Here is a link to a page with charts of recommended tire pressures. I ran across this
information in November, 2014. I mostly agree with the page. YOUR tire size may not be
listed, probably isn't, but you can interpolate & assess/guess. This is one of the very
few tire pressure guidelines that is generic; & does not have lawyers telling the
tire makers to recommend only what BMW (or other mfr) says in their literature
WHICH PROBABLY IS NOT CORRECT FOR THEIR TIRES! I wish Avonmoto had
published for many more sizes. You might notice, even with a quick glance, that
the guidelines don't have anything much or overly-specific to say about TYPES
of tires. That's because differences, unless for specialized purposes, are NOT
ALL THAT PERTINENT. You may notice that tire pressures are recommended
that might be higher than in other tire makers literature, particularly if they use
BRAND names for bikes. That's another way of saying that lawyers have too
much influence! http://www.avonmoto.com/tech/tire-pressure-guidelines
13. When the rear tire 'squares-off'; & some do this rather faster than others (dual-compound
tires are often better at not squaring off fast), handling can be poor in curves, particularly
fast changing twisties. INstability (wobbles) can be very apparent with a squared rear tire,
if such problems happen. See: http://bmwmotorcycletech.info/instability.htm
Some types of instabilities can be HIGHLY dangerous & not just annoying. In some
instances, when combined with, perhaps, an improperly adjusted steering head
preload; & maybe, OR NOT, other things, such as saddlebags, backrest,
windscreen...etc..........you can SUDDENLY get a very bad wobble, at high speeds.
YES, I did just say that squared-off REAR tires can cause problems!
That has been extensively PROVEN & you need not take my word for this!
|14. A bit about me, my testing, etc.....
Penny hates two-up riding, & since I was hardly riding two-wheels on the street anymore; in January 2014, I disposed of the last of my 2-wheelers. In the garage at the time was an 84 R100RT, an HP2, & the K1100LT-EML-EZS conversion. Testing on 2-wheelers did not totally stop, & was sometimes done now & then on borrowed bikes, old friends' & old customers' bikes. I began to miss that RT more & more; even though I had not put many miles on it the several years before I sold it (or, more accurately said, before the new owner finally picked it up, as he had bought it a long time previously, just kept it here, I was allowed to ride it....& maintain it too, of course).
By Spring of 2015 the lack of a 2-wheeler (especially one that was MINE) was really bugging me. I was also beginning to be UNhappy with showing up at various events, TechDays, etc., just on my sidecar rig. I purchased another R100RT, this time a Monoshock 1995. It was my intention to make sure its suspension was in good but STOCK condition, & to, again, do testing on tires that I have previously had NO experience with... or very little experience. BUT, by late 2015 it was becoming apparent that while I was capable of such serious testing, I no longer really wanted-to-be-so-aggressive all that much. I had other interests, such as helping the children in my community by being a very active Member of the Kiwanis of Tahoe Sierra; & Penny & I were active in the community in other ways. I realized after getting back into 2-wheeler riding on the on the street, that I really DID want to do some occasional aggressive riding, but only in short spurts. I tired more easily, I had less stamina, was weaker from the slow part of aging that reduces one's muscles.
I have been blessed in my old age with good reflexes & eyesight. I live in an area that has a variety of terrain, including all sorts of types of twisties in mountain passes. There are some deep sand areas (these "Sand Pits" were actually set aside for motorcycles only), 3 miles from my home. My paved-road testing area gets mixed weather conditions; has various pavement styles & conditions & more than one type of tire snake compounds. A few years ago, the State of Nevada did some paving repairs near here, where they 'tested' a new type of tar snake compound. It was a disaster & they had to remove it. I did a lot of stiction & tire skipping testing on that 11 miles or so of road, on both types of tar snakes. BUT, I could not use the aggressiveness I wanted to, on that particular road, due to the traffic, and the Authorities :-)
Some areas near here that I use are fairly flat & smooth with excellent pavement. One area has very ugly curvy (poor workmanship!) rain grooves & this same road has some broken and uneven pavement sections. I also have a freeway 26 miles distant (with & without rain grooves sections). There is a road I do very high speed testing on (in conjunction with my association with a bike magazine; no, you will not be told who/where). I also have two dirt areas, one is medium hard-pack; one is very soft & deep sand/gravel (that one is, as noted, only 3 miles from my home). If I get on a racetrack with a bike, I will note the types of tires; how they feel/handle, pressures, etc. Since my wife hates seeing me on a track (she does not really want me on 2-wheels at all... besides our bicycles!) I have made some compromises. I have consciously cooled-down my most aggressive testing. I am not as strong as I used to be, age has caught up with me, & I won't heal fast if I drop a bike. SO FAR, I have NEVER, EVER, dropped a bike in my many hundreds of thousands of street miles. I may be just lucky. I am, more & more, depending on tire reports from a few friends, who may be as anal as I once was; or at least agree with my style of testing & can do true analysis. I am, however, still testing tires, less aggressively, with vastly fewer miles per type of tire. My style of testing is likely MORE aggressive than YOUR riding style. Everything is relative, sort-of, EH?
15. ONCE IN A WHILE I will specifically test a bike that has a squared-off rear tire, doing this for stability testing of the entire bike besides tire feel. Same for suspension, stiction problems, etc. I also try to test bikes, when I can, that have large windscreens or fairings, perhaps with tour bags & a backrest.... to see how they handle at various speeds & direction changes. In other words, I may combine bike & equipment testing with tire testing!!
16. For NEW tires, as always, my habit was/is to run the tires in reasonably for 50 to 100 miles, slowly increasing aggressiveness over those miles. I make notes, play with tire air pressures (I take along a small electric compressor & I use a very accurate Bourdon type gauge)....& when I find hot/warm pressures that work well, I recheck with the tires cool, so I know what the normal tire pressure should be (tire pressures for normal use are checked with the tires cool, that is, not ridden yet).
If you visit my general area, you're invited to ask me, directly, about various roads.
19. MUCH of what I hear and read about tires seems to be based on nothing but thin air, or ...the owner has purchased them & WISHES they tested as he says they do. The rider may also have NO IDEA of what he is talking about. I realize this is cynical, but it is the truth. I am WELL-AWARE that few do REAL tire testing, ....but many have UNsubstantiated "OPINIONS". In some instances, maybe a lot of instances, I wish I could share some teaching and riding.
|20. empty on purpose|
Tires by brand, model, & description of performance:
(1) A TUBELESS tire that does NOT use steel strands in the tread is much more likely to
have a LASTING on-road repair, by using sticky strings or internal patch. This is particularly
so if you are using such as the Stop'nGo mushroom type of plugs, which, otherwise, require
a lot of reaming on tread area puncture holes on steel ply tires. The Avon Roadriders,
as ONE example, do NOT have steel plies. Conversely, that makes them POSSIBLY
more conducive to punctures. All this is strictly speculation! I am not knocking
Stop'nGo, I carry their plugger kit with me! I MAY run some puncture tests on tires!
(2) If using metric tires, use the 90-90 or 100-90 front if using 19 inch. Pre-1977 bikes need
a wider fender mount for the wider 100-90 tire, 46-61-1-234-907, this is common to all
brands for that size. I strongly suggest that if using metric sizes on you early TWIN-SHOCK
Airhead, that you use 110/90-18 rear, and NOT a 120/90-18 rear...it is not generally
recommended by me for twin rear shocks Airheads models, specially the rear drum brake
models with cast wheels (Snowflake).
(3) empty on purpose
ROADRIDER (AM26): This is the first new style report of what I hope to do in the
future: that is, highly detailed reporting.
I had, in the past, very limited mileage on the AM26. I was then not fond of them
in moderate to deep rain; nor on paint stripes, & did not particularly like the
AM20/AM21 either. Avon Roadriders (AM26) are moderately priced; DO, reportedly,
seem to get good mileage, but some few have reported the opposite; but in at least
two of these reports, they had some rough surface road miles they often used.
Roadrider's have been reported with cracking. Many, if not most, don't replace
them just for cracking. No reports of actual tire failure problems (AFAIK!).
Since I reported the above, I have had the opportunity to put the AM26 tires through
considerable additional testing. Fortuitously because my 'new-to-me' (1995 R100RT)
bike came with them, with only a few thousand miles on the tires. This motorcycle is
a MONOSHOCK, specifying a wider tire than on early Airheads, on the rear. This
motorcycle specifications are for METRIC sized tires, tubeless-rated & used as
tubeless. The wheels on this motorcycle were stock, as was the suspension.
Standard equipment, with a few notable exceptions: The BMW rear trunk that came
with the motorcycle was NOT fitted. A fairly tall backrest is fitted. The stock stock
windshield had been replaced by a Parabellum, this has a curved bottom design
that allows air to flow at the bottom). I cut the windshield to ~13 inches in height.
That height is not optimum for weather & helmet top buffeting, but allows me the
view & slightly sporty downward forward position I prefer; yes, even on an RT, &
even for my age. I am making these notes because how-fitted AFFECTS HANDLING!
Avon makes these tires in directional & bi-directional (Universal). The tires I did
the testing on were a 100/90-18 front bi-directional tire (stock size for the bike is
90/90-18), with the proper tire direction for the front, as marked on the carcass.
Rear was stock 120/90-18, single direction marked. Rider weight 150. Shortened
windshield (15" much of the time). Tour bags (empty), Tour Rest, NO rear trunk fitted.
1/4th to 3/4 filled fuel tank. Tires were 4 years old FRONT; 3-1/2 years old REAR.
Neither had visible cracking nor other deterioration. Rear tread still rounded.
Tires had ~5000 miles for the initial testing. It was fairly warm for the tests
(70's-80's F.). Both smooth & slightly broken & cracked concrete & asphalt. I
purposely did some freeway riding at low speeds (& up to 90 mph), specifically
hunting-for & using rain grooves, at various speeds. I tested those grooves with
my weight forward, as well as very considerably rearwards.
At first they felt especially twitchy to me, ...same...or more so... as previous tests. I
SOME of this was due to the oversize front tire, which causes the bike to have a
somewhat extra tendency to 'fall into turns'. I did pressure change testing, &
noticed the twitchiness no matter the pressures used. That never completely
disappeared. It took a while to get used to. Direction changes happen quickly
with low input from the rider. Handling over-all is light. Braking is good. These
tires FEEL like not enough rubber is touching the road. They feel like almost any
reasonable pressure I tried was too high, but they STICK WELL...except they are
rather slippery on such as paint stripes. While this is so for all tires, these were a bit
worse. Because of these things, I do NOT recommend using an oversize front tire.
Due consideration should be given if you ride a LOT on rain-grooved roads.
These ties DO moderately track rain grooves; but NOT NEARLY as bad as straight
ribbed front tires do. Some serious testing, perhaps my last time at doing such
highly aggressive testing, was done going both up & down a particular twisty
mountain pass that was rather steep, but smooth, as the asphalt was recently
paved within a couple of months (Luther Pass). Quite a few runs were made to
determine the best tire pressures, which were corrected to cold values. I repeated
the final test on a later cool morning, setting the cool tire pressure to 32F, 36R; the
factory recommended pressure. >>> OVER-ALL, A SURPRISE!! These 1995 BMW
factory recommended pressures worked well!!....for a good compromise of handling
& comfort (BEST performance, pushing the tires rather hard, note my light weight,
was at 35 front & 40 rear). For a heavy rider and/or heavy loads, especially for
touring at high speeds, I suggest 34-36 F & 40-42 R. Over-all, these tires work OK
under all conditions so-far tested, subject to my comments. I think if you need to
fix a flat, that standard soft plugs as provided by Stop'nGo, for use in their special
gun, would work well, & so would sticky strings, because there are no steel strands
to cut the plug or string ....see earlier in this article.
The following caveats:
NO mileage tests ...may be late 2016 before I report on that.
Seem fine on normal lightly wet roads, not yet tested in deeper water.
Slippery on paint stripes, & BADLY so if the road is wet. SAME FOR SOME
Have not yet tested the tires on deeper gravel & dirt roads. Were OK on hard
pack with shallow gravel top surface.
Rain grooves: I fully tested these tires on rain grooves on several roads, including
high-speed freeways, & on two separate occasions, on different roads. They
do follow rain grooves, especially so if the grooves are pronounced and not
straight, but it is mild to moderate, & probably will not overly annoy anyone.
Bottom line: good tire, but I think I prefer the Michelin Pilot Activ over these; but need
more testing on the Michelin; and I haven't any experience on the new Continental Classic
Attack's... yet. I DO think the Avon Roadrider's are worth the cost, which is somewhat
LOWER than the Pilot Activ, etc.
For years, as noted below, the Bridgestone S-11 (Spitfire) tires were ones I used for
comparisons. I think they FEEL considerably more stable than the Avon RoadRider;
even on rain grooves. The Roadrider REAR seems to have rather little squaring-off,
at least at ~5000 miles. I will have more to say on that in the future.
I still like the S-11 & perhaps prefer them for a high percentage of street riders.... all
things considered. For the aggressive rider, these tires are all down the list
Dual-sport riders: the Avon Gripster AM24 has been around for a LONG TIME &
it is a WELL-proven tire; fairly good street tire if a bit noisy, sticks WELL in
cornering, quite stable & not bad in rain either. Works pretty good in off-road
gravel & hard pack, fair/poor in mud, & are, perhaps, a bit rough/hard feeling.
I suggest using about 31 psi front & 35 psi rear for all-around use.
These are possibly not quite as good as the Michelin Anakee for street and dirt.
The Continental TKC 80 is better than the Avon AM24 off-road.
Avon's Distanzia AM43/AM44 is much more of a street tire, decent in the rain, only
fair off-road, but fine for the street rider who ventures off the road on occasion.
This is the Avon Distanzia (front)
NEITHER of these Avon tires would be my choice for a bit deeper or rougher
off-road dual-sport work. Both the Gripster & Distanzia are primarily paved
road tires, with modest to OK off-road capability, the Distanzia having the
edge for the street & life, at maybe 1/3rd more cost. The Gripster is a quite
decent tire for the person who is primarily a paved-road-rider, yet ventures
off the road now & then, who may even be a bit aggressive off-road. The
AM24 is a GOOD all-around tire & works well in anything but mud; keep in
mind that usually only VERY aggressive tires work in mud.
See the Continental TKC80, below.
Bridgestone: S-11 Spitfires (tested: 110 rear, both 90 and 100 front).
ONE of my old favorite ROAD tires, all things considered. They are predictable & good
for the $. I first tried these MANY years ago on a SWB R75/5, & liked them immediately.
Predictable handling in all conditions, although like any true road tire, they
are NOT for deeper soft stuff or mud. Decent mileage & good grip on pavement.
One of the first, if not the first, Dual-tread-compound construction, is part of how
they get the performance (esp. mileage). NOTE!...it is my belief that these tires
AGE a bit more rapidly than many others. The result is that they tend to get a bit
slippery or skittery, more noticeable on wet roads when they GET OLD. While this
could be said for most all tires, these seemed a bit much. I don't recommend these
tires if you don't put on many miles every year...although they are "OK". Not
particularly great if you are an aggressive rider, especially considering the newer
higher performance road tires, especially the new type classic radials, etc.
My recommendation says "all things considered". That means ALL things.
If you want a bit better handling in the wet, & perhaps a bit less aging, then
consider the pricier BT45. In the last dozen years or so, much better tires have
been available, but at some $$$. I used my extensive experience on these tires
as a COMPARISON guide. I no longer do that. Be sure to read the rest, below,
on these tires. Use the 90-90 or 100-90 front if using 19 inch (pre-1977 bikes
need a wider fender mount for the wider 100-90 tire, 46-61-1-234-907, this is
common to all brands for that size). Use 110/90-18 rear. There is a 120/90-18 rear,
not recommended by me for twin shock models, especially the rear drum brake
twin rear shock models. Also available in sizes to fit the later Airheads & also
K bikes. For MOSTLY dry roads, for distance or local touring/cruising, these
tires do fine, just do not try to push them to limits in slippery turns.
My 1984 R100RT got 10,600 miles on the last REAR S-11 tire. The bike was mostly
driven at maximum legal highway speeds (& higher!). The tire still showed tread
that was usable, but it was down to almost 1/16". A good tire for all paved roads,
decent in rain by standards 15 years ago, & even OK for those that ride slightly
aggressively...again, by older standards. To make this CLEAR...these tires ARE
much better than the original tires that BMW put on your older Airhead.
Cheaper than many other tires. For those that do mostly highway riding, with
occasional rides on gravel & hard pack, the S-11 are good because these
dual-compound rear tires do not tend to flat-square quickly, although, like all tires,
it will, eventually. Squared-off rear tires can lead to high speed weaving & other
instabilities, even dangerous types. Again, note that this happens with ALL rear
tires, but these tires DID NOT exhibit it very much. This alone makes their value
good, & considering the handling & mileage, a relative bargain....YES, they
handle WELL....& PREDICABLY....by older standards.
NOTE: The Michelin Pilot Activ, available in INCH sizes, may be much more
competitive to the S-11 and even the BT45 for performance, if not price.
I may have more to say about the Pilot Activ later...so see below for Michelin.
BT-45: Another Bridgestone dual-compound tire. Better than the above S-11
in WET conditions, maybe in all conditions, but at a large $ increase.
I do NOT think them worth the substantial extra cost. HOWEVER, you might.
Perform well, under all paved road conditions. A bit better off-road, than the
S-11. They do not feel the same as the S-11, probably due to the tread design &
possibly an internal carcass change (?). Good, over-all. NOT for super
aggressive riders, since there are better tires....particularly today.
Bridgestone Accolade tires, front is ribbed: I do not have any experience with them.
Supposedly these can produce a more classic, original/early BMW ride.
Cheng Shin: Chinese-made, the brand used to have a bad reputation for problems.
That is NOT SO now. These are good tires delivering OK performance, at a
low price. The 906 model is quite similar to the Metzeler Laser ME33. It matches
well with the 907. Decent tire in both wet & dry. I have not tested many Cheng
Continental: Old TK 16, TK17, NOT recommended. Especially 120 size, which is much
too wide for ANY dual-shock airhead. Listed here only for those comments.
Continental TKH23 front & RKH24 rear are long life tires, available in 3.25H-19
front & 120/90H-18 rear. I cannot remember if that rear can be fit, it might have
the too-wide fit problem as the TK17. BUT, they make this tire in a 4.00-18 rear
...and it DOES fit. Otherwise, decent tires, reasonably priced.
TKC70: More paved-road than off-road. Probably similar to the Metzeler Tourance,
over-all. If your riding is more off-road than paved, try the TKC80. I have
personally not ridden on the TKC70.
TKC 80: Is truly for dual-sport use & still good on pavement. OK even in
rather aggressive riding, although feels a bit squirrely to me, even considering
the tread. Limited sizes available? Grips OK on pavement, on sand & gravel,
dirt, even reasonable on mud! A GOOD choice for those going off-road more
often....yet retains good performance on the street, FAIR when wet, even "OK"
on snow. One of my favorite all-around dual-sport tires. It corners good.
Does not last as long as the Metzeler Tourance. Tossup as to whether you'd
like it over the Avon AM24 Gripsters. The TKC 80 is fairly quiet, inspires
confidence in how it FEELS. I think MOST riders, no matter the model of BMW,
will like this tire, even if you are a street rider but do maybe half your riding
truly off-road. If you want all-around performance in a tire that will be 'capable
of any surface', even some mud, this IS THE ONE. Original equipment on some
Drawbacks: Expensive. Tread too aggressive for "mostly" street riding. Tread
blocks wear weirdly sometimes.
If you like the TKC80, you might also want to try the TrailAttack. You also may
want to look at what I say about the Kenda K784. I have NO experience on the
TrailAttack, & welcome comments. For sure, try the Avon AM24 Gripster, to
compare to the Continental TKC 80.
RB2/K112 (also TK22): Original types used on the OLDEST Airheads as
ORIGINAL equipment. I have not ridden on any in many years; I always disliked
the way they followed rain grooves...but they do...or at least did....offer the
classic BMW soft ride, last pretty good used with original 'high-speeds, two-up'
tire pressure settings. I might try testing some of the new modern versions as I
have heard the rubber compound is improved since Continental re-started
production some time ago on these. I won't use my own bike. Owners of early
Airheads that came with the 3.25-19 front & 4.00-18 rear tires as stock sizes, should
try a set of these Continental tires if they want the classic ride AND LOOK. You won't
get that classic ride if you have a modified suspension. I did manage to test a set (rode
someone else's bike). I think the construction has changed. They are "OK" but not
for true performance riders, especially if you are fairly aggressive.
Note: I don't purchase Continental tires myself due to how they treated my
shop when Continental had a bad batch of tires, many decades ago.
But, I do NOT, in the slightest, want to discourage YOU from trying these
tires, as you may love them. If you intend to ride on classic tires, I also
suggest the Metzeler tires like the ME11, etc. Accolade tires?? BMW
installed Metzelers in the old models/sizes, besides Continental's.
This is the Continental RB2 (front)
Classic Attack Radial (Conti Attack Classic Radial): This is a new type tire from
Continental. Continental says that they specifically designed this tire, A RADIAL
0° type, to enhance & sharpen the handling of older classic bikes which were
originally designed for bias-ply tires. I have not yet tested these tires. From a
look at the tread pattern, I think the tires MIGHT NOT track rain grooves, & should
feel FINE. The tire is supposedly fairly high mileage with excellent grip & fast break-in.
The tire is available only in metric sizes (??). The 100/90R19 57V TL, a front tire, is
expensive, although discounts may be available. That tire, like all of that size, will
probably not fit earliest Airheads without the proper later fender brace, 46-61-1-234-
907 from the 1977-1980 /7 series. Probably will need the later fender too.
The other two usable metric sizes are 110/90R18 61V TL & 120/90R18 5 65V TL, these
two are designed for rear use. I suggest not trying to use the 120 size on anything but a
RS or RT that has the 2.75 rear rim, although you might be able to use the models with
2.50 rear rim. The 110 is likely the BETTER choice. NOTE the load rating
on these tires, compare to your previous and other tires. Note also the "TL". These
tires are V rated; if used with tubes, you should reduce the speed rating by one step.
That's FINE for Airheads, who hardly usually need more than an H rating, let alone an S or
V. Some riders who have tried these LOVE THEM. As noted, no personal testing
information yet. Tom Cutter reported that these type tires were easy to R/R, provided a
comfortable ride, were stable, and had a nice feeling.
... somewhat expensive. Other sizes may become available.
I am looking forward to comparing these tires to Michelin Pilot Active & Avon RoadRider.
Dunlop: Vintage K70 front, 3.25H-19; K70 rear, 4.00H18/.
Somewhat similar in some respects: Dunlop F11 front 100/90H-19; use it with a K627 rear
110-90H-18. Reasonably OK, obsolete now.
K491-Elite II: This was a Premium-cost tire, premium priced and a VERY long lasting VERY high
mileage tire. Pretty fair wet handling too for such a long lasting tire, and good on rain
grooves and reasonable IN RAIN. Use 90-19 front (some can use 100-90) and 110/90-18
rear. The oversize 120/90 rear should also fit the early eighties Airheads. Tire has
probably been discontinued. It was a classic high mileage tire when available. Some
loved them for LD touring on both lighter and heavier bikes. My tests agreed.
TrailMax Dual-Sport: can't recommend these; pretty lousy off-road.
D606: This is a good mixed use tire, for tarmac AND off-road. It is priced in the lower
area, and is good on road and off-road....with an emphasis for off-road. My limited
testing found some high speed instability, but I did not have time to test pressure
changes nor loading in that regard.
Good performance for the cost. I think the Michelin T63 is better.
GOOD TIRE...and you MIGHT like it over the Conti TKC80.
Heindenau: The K60 Scout tire is nearly as aggressive as the Continental TKC80, but costs
a LOT less. You may really like them, over-all. LIMITED experience.
Kenda: K784 Big Block. So-so on pavement, pretty damned good off-road, even quite good
in mud. Wears relatively fast...to be expected for good off-road and even mud type tire.
Maxxis: C6011 is good, not sure if it is available in the 18 inch now. See Cheng Shin comments.
Metzeler: (see Continental, RB2/K112, for comments regarding the Metzeler ME11)
***UPDATE, November 2015: Metzeler has moved some of its existing tires & some new
versions of old types, into a new category, called the Heritage series. While
this includes the Lasertec, it also includes some classic Metzeler tires, mostly
updated with newer compounds and manufacturing. This should bring better
handling & longer life, but I have NO testing experience on them. The tires
will mostly have the original tread profiles & appearance. These tires are
the Perfect ME11 front, Perfect ME77, Block C.
ME33 Laser: both standard & the low profile metric. I recommend the 3.25 or 3.50
front. If you have gone to an oversize rear, use the oversize front. This tire will SEEM
to follow some types of rain grooves, but NOT as badly as a ribbed front tire. You can
use this front tire with many other rear types. Decent in the rain, good dry grip (LIKELY
WAY beyond your bike's capabilities). For mileage, you can expect decent, if not
outstanding values. Some tendency, sometimes, to cupping. The ME33 tread design
was unique when introduced & has been copied by others. It has a lighter faster
turning 'feel', & almost always can be used with just about any rear tire design. There
was a K compound version that was, well, good enough to race on! Both NLA, I think.
Lasertec: I do not like this tire ...NOT for the less-aggressive rider. It is twitchy,
gives an unstable feeling. Aggressive riders might want to try it. This tire does NOT
feel like the ME33 Laser to me. The tires have been reported as inconsistent in
manufacture. That may be so. They tend to follow rain grooves....likely due to its single
circumference groove (or multiple wiggle type) groove(s) in the center of the tire. If you
don't have grooved highways, or don't mind the (not awful) instability, then you MIGHT
like this tire. I was surprised by the twitchiness, & while different, I compared its
twitchy feeling to the Avon RoadRider. The twitchiness may be partly a "less-rubber-on
-the-road" FEELING. I did NOT do tire pressure testing. NOTE that a lot of the more
modern tires have some very light handling qualities, which I call twichiness. You
may want to try this tire. It DOES stick "OK", corners nicely; gives "some" confidence
in tight twisties. This tire should match up with many of Metzeler's other model type
of tires. I just do not like the tire.
ME55: An old favorite for some, was also available in 120 size for the rear. I never liked
this tire much, although it gave a good compromise on handling & mileage.
ME88: Front & rear versions. A mileage tire, reasonably good handling; one of my
old favorites for use front & rear for TOURING. Interestingly, this tire also worked well
as a rear with ME 33 Laser front, for more aggressive paved road riders. I have tested
ONLY those made in Germany. Discontinued...booo hooo.
ME880: NO personal tests yet; no trustworthy reports yet either.
Tourance: OK on the street, "fair" on gravel and hard-pack dirt. The Michelin
Anakee is probably better all-around, by a bit, wet and dry, for dual-sport. The
Continental TKC70 is roughly the same, performance-wise, as the Tourance.
Tourances are NOT good in any sort of mud.
Enduro tires: Metzeler has a selection of these tube type tires to fit older airheads.
The Enduro 3 (Sahara or Sahara 3) is a good one for mixed on-off road. It is premium
priced, however. Watch the WIDTH....Enduro tires may be MUCH wider than their size
might lead you to believe; thus may not fit on twin-shock models, due to swing arm
clearance problems. Nearly every motorcycle tire manufacturer has its own enduro tires.
Metzeler MCE Karoo: These are good GS type tires for off-road, fairly decent on
pavement. I suggest you don't mix other types on the same bike. For pavement
use, especially if the weather is cold, let them warm up before getting aggressive with
them. Many equate these tires with the Continental TKC80, I think them only
somewhat similar. There is now a Karoo 3...no information nor testing by me, yet.
Macadam 50 & 50e. 100/90-19 & 3.25-19 front; 110/90 & 120/90 & 4.00 all in 18 inch rear.
Some really liked these. I don't have enough miles on them to say much.
The Pilot Activ replaces the Macadam. The Pilot Activ SEEMS, in LIMITED testing by
me, to be better for wet streets, handles better, reports say long life; may be comparable
to the Bridgestone BT45, per SOME. I, however, think it SUPERIOR. In 2013 I installed a
rear Pilot Activ 4.00H18 on the REAR of my R100RT & did mild testing. The front was still
a 3/4 worn Bridgestone S-11. I intended to later install a front 3.25 H19 Pilot Activ, & do
testing all over again, but no longer have the bike. The REAR Pilot Activ worked nicely
with the very different tread profile on the worn front Bridgestone, and with different
pressures too. Previous tests on someone else's bike, with BOTH tires being Pilot
Activ's, were not extensive enough for me to say much more until Summer of 2015.
BTW...I had a miserable time trying to mount the Pilot Activ 4.00H18 to the 84 R100RT
rear snowflake wheel. One side went to the rim bead area OK, the other VERY difficult.
Because of this, I modified my air equipment AGAIN, & then it went on OK. I added the
new inflation information to my http://bmwmotorcycletech.info/tirerepair.htm article.
This tire is very stiff in the sidewalls, even the tread. Do not be discouraged by these
remarks. This tire has a very well-made bead edge, which should offer better sealing
on a tubeless rim than others...but a tubeless rim & a tube type rim do NOT have the
same shape for the bead area...the angle can be 9° different in some cases. For those
who use a tube type rim as tubeless, I think this tire will do better than many others
in the instance of an air leak or flat. This is speculation on my part. Such usage is
not recommended by many. There IS an article on this website about such usage.
I used standard Michelin Butyl tire tubes for my testing.
NOTE: In the summer of 2015 I had the opportunity to test ride a WELL-MAINTAINED
R100RS with BOTH front & rear tires being these, with less than 2000 miles
on them. I asked the owner to let me ride the bike & test the tires. Luckily, it
was someone who has ridden with me before & he said yes. I did a fairly
thorough testing, but NO testing was done in soft stuff, nor on wet roads. I
did some pressure testing. I first rode locally, then did three passes, & then
on a nicely repaved but broken-in asphalt road with several substantial twisties
& one slower speed tight turn, through which I very aggressively rode. On the
way home, I did a higher speed highway & made a detour onto a freeway with a
constantly tightening radius downhill entrance. The initial part of this freeway
is my favorite area to test for rain groove handling.
I felt it a good idea to somehow pay the owner, & so I treated him to a very nice
lunch. I did ~93 miles on them. I am VERY MPRESSED with these tires. I have
no idea what mileage would be obtained. MY NEXT SET OF TIRES WILL LIKELY
BE THESE FOR MY OWN BIKE. I think them one of the best handling of the
modern tires for street usage, possibly THE best I have tested. Very impressed!
Anakee3: The Anakee 3 is different from the Anakee 2. The 3 is for mixed on and off
road, seems pretty good all-around until you get into mud, where it's poor. Emphasis
is on pavement riding. EXPENSIVE. May be difficult to mount? Competition for these
tires are the Continental Trail Attack, the Avon Distanzia, and Metzeler's Tourance.
T-63: For more aggressive off-road riders, handle decently on dry pavement (not
too bad on wet roads either); probably one of the best buys for mixed use (dual-
sport, with a fair amount of emphasis towards off-road). The T63 is a truly good tire.
A friend told me about this tire, & how he, on a bike loaded with luggage & his
girlfriend on the rear of the seat, practically melted the tire from very high speeds,
in Arizona, in exceptionally hot weather. I went out of my way to test this tire on
someone's bike. It is less expensive than much of its competition. This tire has a
moderately aggressive enduro tread, so unless you do some off-roading, don't get it.
This is NOT the tire for quite heavy loads at quite high speeds, coupled with very
hot asphalt (see remarks!). NOTE: I have ridden ~ 78 miles on an Airhead equipped
with these. My opinion matches someone else's, who rides aggressively. While the
tread does look aggressive, the tire is somewhat milder than it looks. I do not know
about expected mileage life, but I think the tire worth the modest cost.
Pilot Road 2: Seem to be excellent on Classic K-bikes...very limited experience here.
OVER-ALL, I am IMPRESSED with the Michelin brand of tires. Even for my SUV.
Pirelli: Scorpion: Not recommended for GS. I have NO miles on them. Some reports
say they exhibit wobbling if mixed with other tires, but I have no definitive information.
Sport Demon: reportedly will change handling for the worse AFTER some miles
are on them. NO personal experience.
Shinko: NO PERSONAL aggressive testing yet. One report from someone whose riding
skills are very good & can ride hard enough to test tires reasonably well, likes
these, & compares them to vastly more expensive tires.
The "everything else" section of this long article:
1. Some folks have trouble understanding tires sizes. On metric tires the first number is the width in mm on a
nominal width rim, the second number is the aspect ratio of the sidewall to tire height. Metric sizes and inch
sizes are not exact equivalents. GENERALLY speaking a 3.25 inch size as originally specified can be
substituted by a 90 metric (often coded as MJ); a 3.50" by a 100 metric (MM); a 3.75 or 4.00 by a 110
metric (MN or MP); and a 4.25 or 4.50 by a 120 (or MR).
There WILL BE handling differences if you do not use the originally specified size of tires. Those that have
heavy loads ...may want ONE size oversize tires. It may behoove you to look into the load carrying capability
of your proposed new tires...usually molded/printed on the sidewall. SOMEtimes a larger tire is rated for a
LOWER load. Using a stock rear tire, let us say 4.00-18, with a substantially oversize front tire, is not the
best combination, as the bike will PROBABLY have a tendency to fall into turns a bit; but I have NOT found
that too excessive if not going too big. As I noted; sometimes an oversize tire will have LESS load
capacity, and you MAY have to look at the manufacturer's technical data to find this out.
***SOMEtimes an oversize tire will have LESS contact patch on the ground....due to the round
profile! Do NOT willy-nilly increase tire sizes! This is particularly so for the front.
IN GENERAL: OK for a 3.25 front to be 3.50 or 90/90 or 100/90; and, OK for a 4.00 rear to be 110 or
120. There is a 4.10 size that MIGHT work, but I have NO DATA, NO EXPERIENCE. I also have very
limited information on using 80 profile tires....Aspect ratios of 80% will NOT always work on early Airheads.
It is often a matter of the sidewall characteristics not just other fitment problems. Most of the early
Airheads came with inch size tires: 3.25 x 19 inch front tire and 4.00 x 18 inch rear tire. For some time
FEW tires were made in those sizes, but availability has improved. In general, these old sizes were in
what, today, is called a 90 profile. Some were closer to an 80 series. NOTE that the old Airheads
(except G/S) did not come with enduro tires, and I mention this because most enduro tires in 4.00 x 18
will be VASTLY wider than a 4.00 x 18 paved road type of tire. An enduro tire may well NOT fit on twin
shock Airheads, not enough room between tire and driveshaft housing. This is particularly so on those
before 1981. These can have a wider right side of rear wheel spacer installed, and BMW even sells such,
but that may not help enough. For the front tire, which came as a 3.25 x 19 (and in some cases, like the
R65, 18"), you can usually go to 3.50 x 19 or metric 100/90, but you might have to use a later seventies
fender mount. More much later in this article on that. A 90/90 or even 100/90 on the front, and a 110/90
on the rear is very common and USUALLY WORKS WELL on Airheads. In some instances SOME 120
will fit the rear; BUT, sometimes (pre-1981 for instance) one has to get the wider 10.7 mm spacer for the
right side of the rear hub...BMW part number 36-31-2-301-737. That spacer change has been needed
sometimes for 110, but not often; more often for 120. Stock was 9.2 mm, and was 36-31-4-038-142.
The spacers are VERY easy to install, and do NOT affect bearing preload. A few 120 rear tires fit rather
tightly on drum brake models; that is, the wheel with tire mounted to it is a bit difficult to install, and at
least deflating it is needed. NOTE: BMW uses 'top hat spacers', or call them brimmed spacers,
at various places in the bikes. You will find them at the swing arm sides, and the wheels.
One top hat spacer, part number 36-31-230-322, was originally an exceptionally WIDE hat type,
and this spacer has been sometimes used to space the rear wheel to the left even more. That
spacer is 12.9 mm wide, and the hat is nearly 32 mm in diameter.
In general, 120-18 rear tires on twin-shock airheads are NOT recommended by me, but also NOT
recommended against.... although I certainly have had a lot of them on my various R100RT bikes.
The part number used by BMW for some of the top hat spacers at the swing arm bearings is
different than the almost exactly the same 9.2 mm part used at the wheel bearings.
They are usable however!
BMW modified the REAR WIRE SPOKED wheels for extra clearance, and this was done in the /5 days,
as well as the ST and G/S days, and it was done by offsetting the spokes; details elsewhere's on this
site. While many think that the ST and G/S 3 mm offset change came when the REAR wheel went to
a 2.50 from a 1.85 size, this is not so, it was later on ...after that change.
2. The rear fender can be modified, hardly shows, makes tire changes easier.
http://bmwmotorcycletech.info/RearFenderMod.jpg for a photo.
3. The BMW tube-type snowflake wheels are "WM2" in rim SHAPE. Other articles of mine
treat the use of tubeless tires withOUT tubes. Click here for that link,
It is almost always OK to install a tubeless tire WITH tube into a tubeless wheel...but
mentally reduce the speed rating by one grade, due to heat buildup with a tube.
4. Try not to purchase tires more than THREE years old, date codes are on the sidewall, showing
week of the year & the year.
5. The maximum inflation pressure shown on the sidewall is for normal use, not for inflation to seat a bead,
which is higher, just how much higher is subject to safety concerns. For installing tires I don't go over
60 psi, try to stay at 50 psi, and use lots of REAL tire lube. Generally the manufacturers will allow up
to 50% over the sidewall printing for mounting....be cautious, if a rim explodes you can be seriously
injured. THE secrets to seating a tire are to have the rim bead area CLEAN and SMOOTH, use
LOTS of the RIGHT type of lube (REAL tire lube) and have the tire and wheel (and tube if used )
truly hot from being in the sun! ...AND!!!!....TO REMOVE THE VALVE CORE ....AND ALSO
REMOVE THE TIP IN THE HOSE CHUCK. USE A 125+ PSI 3 GALLON+ TANK ON THE
COMPRESSOR & large inner bore size fittings & hose. ALL THIS SO THE INRUSH OF AIR
IS FAST. YES, the SPEED of the air inflation is a BIG secret! Even so, an occasional tire will
prove to be difficult.
6. NEW tires are VERY slippery!.....allow 20-50 miles to scrub them off. I prefer to first thoroughly
brush the tires with a fairly strong detergent and hot water mixture, and then flush them, before
riding on them. I use a stiff bristled old-fashioned floor scrubbing brush.
7. Continuous speed rating is marked on the tire, usually as part of the number/letters of the tire size. Tires
with deeper tread MAY wear longer, sometimes they do not, from the same manufacturer. Deeper tread
tires are generally rated lower in speed, and usually are the better buy for touring. If you do not ride at
warp speeds, an H rated tire may be a much better buy than a V rated, as an example. MAY is the word
here. Sometimes the only difference is TREAD depth....the higher rated tire having a LESS deep tread.
This is not universally so. Another way of stating this, a bit differently, is that a higher rated tire is NOT
necessarily a better tire...for YOU!
Here is a chart of what the letters mean.
Remember, if you install a tube in a tire marked tubeless, reduce a grade):
Letter Km/hr mph
B 50 31
C 60 37
D 65 40
E 70 44
F 80 50
G 90 56
H 210 130
J 100 62
K 110 68
L 120 75
M 130 81
N 140 87
P 150 93
Q 160 100
R 170 106
S 180 112
T 190 118
U 200 124
V 240+ 149 Note that some V or VR tires may be rated for OVER 149 mph
W 270 168
Y 300 186
Note that there is a Z and ZR rated group, they also are over 149 mph like the V/VR
(A) Sometimes sidecar folks will use a tire designed for rear use, on the front.
If you do so, & the tire has a directional arrow, you can REVERSE the tire, so the direction
arrow is in the 'wrong' direction of travel. Some tires are bi-directional, & maybe with two
markings for direction, depending on if used for front or rear.
(B) For sidecarists, 16 inch rims CAN be used for passenger car tires OR motorcycle tires (if rim
width is proper). Do NOT generally use or try to install, a 15 inch m/c tire on a 15 inch car
rim, nor 15 inch car tire on a 15 inch motorcycle rated rim. You MAY be able to use a 15"
car tire if the motorcycle rim is skimmed on a lathe or the car tire is a quite small one.
***PLEASE HEED THESE WARNINGS!!....MORE:
15 inch car tires and 15 inch motorcycle rims are NOT the same diameter!!! 16 and 17
inch seems OK. If you insist on putting a 15" car tire onto a 15" motorcycle wheel, the smallest
tires may work OK, the larger ones are definitely dangerous to mount. YOU CAN HAVE A
CATASTROPHIC FAILURE! NOTE that some sidecar manufacturer's use 15" car type rims.
9. There ARE reasons to NOT screw the tube valve stem nut
to the OUTSIDE of the rim:
(A). No allowance for tube movement if one has a leak, and the tire rotates on the rim some.
(B). If the tube seals to the rim too well, it can trap air from tube to rim, and allow tube chafing.
The purpose of the tube nut is to help DURING installation of the tube...and can be
discarded...or run up to the cap...after the mounting is done. These ARE NOT just my
ideas! I can quote from tire manufacturer's manuals...and a BMW bulletin...on these facts!
(C). BMW has had at least two bulletins out on these valve nuts, and one SI gave an additional
reason to have it up against the cap, that was that improper inflation could cause the tube
to be weakened at the valve stem and if the nut was at the rim, and not the cap, the stem
could disastrously tear out, suddenly. What BMW did not say, was that this comes from
very low inflation AND overinflation during seating of the tire.
My tire repair article: http://bmwmotorcycletech.info/tirerepair.htm has a lot more information
on use of nuts, concave washers, etc.
10. Inflation is usually in psi (pounds per square inch), but some tires have it in BARS. Bar means
BARometric pressure, one Bar is atmospheric pressure, ~ 15 psi. NOTE!! manufacturer's, such
as Metzeler, used to have in their technical books, information that during mounting, the maximum
inflation pressure (DO use plenty of tire lube!!) was 150% of the tire sidewall printed value.
Manufacturer's are getting lawsuit conscious....and many now say not to exceed the sidewall
printed value, or 20% or some such. Because 150% can be interpreted by some to be 150% on
top of the original pressure, some manufacturer's changed wording to say 50% increase over
maximum sidewall-printed pressure. You are on your own. I do not go over 50 psi unless I am
forced to, and it is very rare indeed that I go to 60 on a motorcycle type tire. This is NOT an
OK for YOU to do that! An exploding rim can kill you. Seating of modern stiff tires onto
the rim is usually THE problem seen. USE LOTS OF LUBE, on a smoothly cleaned bead
area of the rim and have the tube and tire hot from being in sunlight. MIND the hints
I gave, on having things hot in the sun, using a modified chuck, no valve in the valve
stem, & lots of lubricant.....this really really does work well.
An old "Rule of Thumb" says that after a considerable number of miles, the cold
temperature pressure in a tire should have risen to ~8% higher with the tire is hot.
That is generally true, but not all types of tires seem to conform, particularly some belted
& radial types. Still, it can be a useful idea. Where this idea came from is actually the
manufacturers of tires. If the pressure is too low, the tire will flex more, creating more
heat; if pressure is too high, the tire will not heat enough. Tires require the correct
pressure for handling & life, etc. Sometimes when I relate this, someone will ask about
tire temperature. Road tires are designed to run at ~130°C at the contact point. That is
VERY HOT. That was NOT a typo, it IS degrees Centigrade. That contact point cools off
VERY rapidly when you come to a stop, so you can pretty much forget about trying to
measure it; particularly with a non-contact meter, that many seem to own, that does
not respond well/accurately to black tires.
Many TIRE manufacturer's used to tell you the REAL tire pressure to use or try with their tires.
Lawyers probably got involved; most literature now just shows the motorcycle manufacturer's
recommendation......which may be too low for Airheads (generally BMW recommendations are
pretty much correct on the single sided rear end Airheads & usually any Airhead from ~1985)...and
NOT correct, seriously not, for modern tires on pre-1985.
BMW had recommended tire pressures on a label someplace under the seat & in the owner's manual.
Some later BMW literature upped some of the old pressures to SOLO 32-34 psi, both front & rear. That
pressure is STILL LIKELY NOT correct for YOUR riding, tires, conditions. I have found almost NO tires
that should have 32 psi in the rear! Modern tires NEED higher pressures: 33-36 front;38-42 rear.
11. Motorcycle tires have had for some time a LOAD index coding, something like 81H. The tires may
eventually get the standard car tire coding of alphabet letters for wear and heat. If you pack heavily,
perhaps you weigh a lot, and you have a passenger.....pay attention to the manufacturer's published
information on loading allowed. SPEED rating is downgraded by one grade if a tube is used in a
tubeless-rated tire. TL means tubeless....does NOT mean you MUST run it tubeless. - means bias ply;
R means radial; B means bias belted. A FEW tires marked tubeless should not be used with tubes.
Ask, and look at the sidewall printing too.
12. Airheads came with a number of different rim WIDTHS and TWO GENERAL SHAPES. BMW used the
WM2 rim SHAPE up until they installed tubeless tires, not officially OK with tubeless tires withOUT tubes.
Many arguments abound about this subject. The WM2 rim does NOT have the 5 degree increased angle
of the flat area inside and the side area...all of which the tire bead rest against. You are ON YOUR
OWN if you fit without a tube, in a snowflake wheel designed for tubes. Rim width and tire size fitted
must be within a range of values in order to not only fit into the fender/brace/etc; and swing arm on the
twin shock models.....BUT...if a tire is too wide for the rim, the tire will tend to roll in turns, making for
lousy handling. EVERY tire manufacturer has a recommended range of rim sizes for each model
and size of tire. Those recommendations ARE correct. Early /5 rims were 1.85" on front AND rear.
Later /5 bikes had 2.15" rear rims. The 1.85" front rim was carried along right up to 1984 on most models.
The R80G/S had the narrow 1.85 front rim, and early ones the 2.15 rear, then came a 2.50 rear. Of
course, those G/S also had a 21" front wheel. Some of the bikes came with a 2.75" rear rim...this was
on the 1978-84 RS, R100S; and 79-84 RT with disc brake rears; the drum brake rear bikes in these
groups were generally 2.50". With the Monolever and Paralever bikes, things changed with the rims
again, with a new rim design, for tubeless tires withOUT tubes, etc.
An EXTENSIVE article on using various rims as tubeless, etc., is HERE:
13. Some have a hard time getting a pressure gauge onto the valve stems of the snowflake rims. There is a
90 degree stem adapter available from BMW, I don't recommend its permanent use though. FRANKLY
I don't use them at any time. 71-11-1-239-258. Any of the stock type, 45 or 90 degree head, pressure
gauges are fine....just check their calibration once in awhile.
For other purposes (than difficulty with using a gauge), BMW also has a steel, chromed, straight valve
stem, for use with tubeless (and for snowflake conversions, but this is NOT officially approved), it is about
$4 from BMW...and is available elsewhere's cheaper. The BMW number is 36-32-1-452-748...and this
part is vastly nicer than a typical small car or yard vehicle all rubber stem. You cannot get a good seal
with that stem, unless the inside of the rim has a flat milled place for that valve stem.
14. Most flats/punctures are on rear tires. MANY can be avoided....by simply putting a LONG mudflap onto
the FRONT fender, the closer to the ground the better. Nice looking ones are available. You may have
to drill some holes, use screws, washers, nuts. What this flap HELPS to do (theory anyway) is to
deflect road garbage being thrown backwards, perhaps standing the debris upright.....and into the
path of the rear tire. Hence, the type that hangs down the furthest is desirable. The truth is a mixture
of that, and the fact that the REAR tire provides the tread-distortion of acceleration and engine braking.
15. Tire dating:
Tire sidewalls have a lot of information. One area shows the manufacturing DATE. On earlier tires,
prior to year 2000, there were THREE digits... first two digits meaning the WEEK of the year, and a
third digit for the year. In the 1990's, there was a small triangle to identify that it was made in the
1990's. Sometime during the 2000 year all manufacturer's changed to the 4 digit system, the first
two digits being the WEEK of the year, and the last two digits being the YEAR. If the tire code was
455, you know the tire was manufactured in the 45th week of a year ending in 5 (but it had to be 1995,
if the triangle preceded). The reason only three digits was originally used was that the bureaucrats
thought that tires would not likely be in service for over 10 years.
There is additional coding you may be interested in. There will be something like the following:
DOT ENYO VLK 1704.
What you MAY be interested in is the two letters after DOT, in this example, EN. These can be looked
up at http://www.harriger.com to find out what factory they were made in. I have PURPOSELY not
listed the exact URL for the specific PAGE in that website, as INTERNAL links do not properly relate
to outside full URL's.
There is a longer DOT code in use now. The DOT coding begins by some letters and numbers. The
first two letters identify the factory. The list is at: www.harriger.com/tiremakers.htm. The last 4 digits
are the week and year, as above. NOTE that while DOT regulations mandate information on both
sides of the sidewalls, you may have to look in two places and on both sides for the ENTIRE identification
numbers/letters. The original reason this was done was, supposedly, to reduce problems with the
manufacturing and mould interference.
16. Recommended and NOT recommended tire vendors. This section is not kept-up to-date.
a. NOT recommended: MAW (www.mawonline.com, Motorcycle Accessory Warehouse).
: Discount motorcycle tire and accessories.
b. OK; but pay attention to shipping charges, sometimes if you buy TWO tires shipping is
free. Pay attention to date codes.
Motorcycle Superstore, Medford, Oregon. Cheaper if order is over $89, free shipping.
SW mototires (no shipping if buying two)
Generally, BikeBandit has decent prices and decent cost for shipping. AMA members get
10% additional discount.
c. Don't forget to do a thorough Internet search; and, do NOT forget about your local
independent service ....and even your BMW dealership.
There is BAD information, or just plain hype, on the use of nitrogen in any type of tire
for road & off-road use. The facts are, that while there ARE benefits, use of nitrogen to fill tires
is NOT very practical for anything but racing. On the plus side, molecules of nitrogen are larger than
average air molecules. These larger molecules do NOT pass through the rubber used in tires and
tubes as easily as common air molecules. Thus, pressure loss over time is lower, this is particularly
so with higher percentage natural rubber tubes, as opposed to the lower percentage natural rubber,
often just called plastic tubes. On a practical basis, the slower loss is NOT a BIG difference to most.
One factor not talked about much is that nitrogen is available in different percentages, and the very
high percentage version is THE BEST. BTW...CostCo, which does NOT sell motorcycle tires,
DOES use the premium nitrogen. A plus factor for nitrogen is that it is less prone to accumulate water
vapor, and, is very DRY when installed into the tire, not so the 'outside air' from your average
compressor setup, nor a gas station. Water vapor in common compressed air can lead to rather
wild fluctuations in pressure as the tire heats up & cools down. Obviously, this is minimized by using
clean, dry, air. Nitrogen, due to its lack of extra affinity for water vapor, delivers a safer, more stable
tire pressure, which can be somewhat important for very high speed driving (much more so at racing
speeds). The final good point about nitrogen is that it does not contain oxygen, which tends to degrade
rubber compounds over long periods of time. The PROBLEM with nitrogen is cost, not easily available,
and if you top off the tire with even a modest amount of compressed air, especially if the air is not
dead dry, some advantages of the nitrogen is LOST. This is very much LESS SO, if the nitrogen that
was used is a very high percentage type. Nitrogen's good effects work with tubeless AND tubes.
There are instances wherein someone uses a tube-rated tire without a tube. In some instances this
is done with various motorcycle tires, but also done with two special sidecar type tires.... and, there
are only TWO types of these square-profile sidecar tires available, as far as I know. One in 18"
and one in 19", and not from the same manufacturer! (19"=Avon Triple Duty; 18"=Metzeler Block K).
I have tried nitrogen in these tires in these situations, and it appears that tire pressure loss IS
SLOWER. Since the pressure loss from these two tires CAN be more rapid than with tubes, this is
something to consider.
Another usage is a tubeless tire used on tube-rated rims. That brings up a whole story in itself,
and has its own article on this website: http://bmwmotorcycletech.info/section6.htm. I have done
some preliminary testing; leakage does seem less with nitrogen. The bottom line, of course, is
few of you are going to buy or lease nitrogen tanks for use at home....but some bike dealerships
may be using nitrogen.
18. TIRE WEAR: The reasons for various "strange" tire wear & why one side of a front motorcycle tire
wears so much faster than the other side...& why downshifting for braking instead of using the brakes
(downshifting for braking lowers tire mileage); & a LOT more, is in the following article, which is so
good that I never wrote such a complete article myself: http://www.rattlebars.com/tirewear/index.html.
The only thing NOT well-explained, is why some two people with identical makes, models, & years of
motorcycle, with the same make, model, & pressure in their tires....& the same riding habits &
styles....will, or can, have such different tire wear. I'm not going to get into that, HERE.
There are several types. It does NOT have to be on water! The TWO types of hydroplaning that
YOU are likely to be concerned about are called (1) Dynamic Hydroplaning; and (2) Viscous
Hydroplaning. Both occur on wet roads, although the viscous type might be said to ALSO occur
on ice. You are unlikely to be much concerned with the two other types of hydroplaning, except
maybe you might have a passing interest in the fact that if the brakes are used hard enough to
STOP a wheel from rotating (and you are still moving), you MIGHT heat up the rubber at the
contact point to where the rubber REVERTS to its PRE-cured condition; then it just plain slides,
like on ice. Dynamic hydroplaning occurs when the water in front of the tire can not be moved
away from the contact surface fast enough. The actual science deals with the water pressure
'being rolled up'. That pressure is opposing the pressure the tire places on the wet surface
(the weight of the motorcycle normally on that tire contact with the surface). Various things
have an effect on just when hydroplaning will occur:
softness & other factors of the rubber compound; road surface; tire profile; type of rubber;
tread depth. All those things would seem to be 'common sense'; and, yes, they are; but not to
the degree you may think. NASA did a LOT of testing; their testing has since been re-proven
by motorcycle & car tire manufacturers, & the results are that a major variable in dynamic
hydroplaning is from the PRESSURE in the tire. The depth of the road surface water
NEED NOT be very much at all.
Hydroplaning CAN, surprising some of you, occur with quite deep tire treads ...at a speed, in miles per
hour, as low as 9.9 times the square root of the pressure in PSI. The figure for nautical miles per hour
is 8.6, usually what is seen in various publications, usually not mentioning that it is nautical, NOR that this
is "STATIC speed"...and no explanation). If you are MOVING, the speed is LOWER! These points
are almost never in any articles about hydroplaning! Welcome to Snowbum's anality and verboseness
and providing extra facts. Once hydroplaning starts, it can remain for MUCH lower speeds. You
are in danger of suddenly loosing control, from JUST hydroplaning on a wet road, even with
really good & deep tire treads, at speeds as low as 45 mph if inflated to 27 psi; 56 mph if
inflated to 42 psi. If standing water is fairly thick, these speeds are much reduced, although
some say there is no difference...the REASON is that they are talking about CAR tires, or
reciting from literature meaning CAR tires. In any case, note that hydroplaning speed rises
...a good thing...as pressures RISE. This is exactly backwards to what some riders believe. They
think that in rain, they should LOWER the pressures. In one way, they are correct!...the bike will feel
more jittery, less planted, with higher pressures (assuming that the higher pressures are higher than
the recommended pressures). Since the front tire is almost always the critical tire, & almost
always has the lowest pressure, beware of excessive speed in the wet!.....you may loose
control without using the brakes & much more likely if using the brakes, even gently).
I am well aware that most of you probably think if you LOWERED the tire pressure, it would
either grip better on wet roads, or be less likely to hydroplane. Keep in mind that hydroplaning
is just one factor; you can easily loose control due to insufficient tread depth, oil on the road
or floating on the water, wind from the side; a host of other factors. What all means is that
you can loose control at a VERY much lower speed than that for JUST the published
"Viscous hydroplaning" is the type, at least on your motorcycle, that you might encounter
if the road was rather smooth & the tire getting rather bald. This can occur at very low
speeds and VERY low amounts of water on the road.
If you are or beginning to, hydroplane, it will be like riding on ice. It is my opinion that on modern motorcycle
tires if your tread depth is at least 3 or 4 mm, then the MAIN influence on the speed at which hydroplaning will
occur, is the tire pressure and the thickness of the water on the road. If you never ride in the rain, you won't
likely worry about hydroplaning. It is also true that there are very soft special rubber RAIN TIRES available for
racing. They have special treads, and a lot more, and are NOT part of my discussion, beyond this mention.
The safest thing to do if in the rain is to reduce your speed GREATLY, and be gentle with leaning and brakes.
For common ordinary street tires for your motorcycle, some are better than others in the rain (or, just mildly
wet roads). The manufacturer's literature MAY...or may not.... be helpful in this regard. I can say the same
for anecdotal 'evidence'....that is, can you believe what fellow riders say about a tire? If a LOT of your fellow
riders have run the SAME tire, and nearly the same pressures, and they live in really rainy areas...well, I'd take
THEIR word about the best street tires for rain....over the manufacturer's claims, or from someone who rides
gently once in a great while on damp roads.
GENERALLY speaking, the LONGEST wearing street tires are the worst for rain.
BUT, this is not universally so. Some premium long-lasting street tires are quite good when it is raining.
20. Tire sizes; rear swingarm clearance, ETC:
Much of this information is also posted elsewhere's in this website. It is shown here on purpose....and
expanded upon a bit.
The original tire sizes for all the early Airheads was 3.25 x 19 front, and 4.00 x 18 rear. Some manufacturer's
still make those size tires. For those wanting to go to modern metric sized rubber, the 90-90/19 will fit all the
19 inch front wheels, and the 100-90/19 will fit the earliest models front if the fender support brace is changed
to the later wider type. The later wider fender brace you would want is the 1977-1980 used on the /7 bikes.
The BMW part number is 46-61-1-234-907.
For the 110 or 120 size rear tire, problems will be with the wheel/swingarm/discbrake stay area. Most often,
the 110 size fits withOUT any spacer changes. Either the 110 or the 120 will do for the rear; but I recommend
you NOT get the 120. You MIGHT have to go to the slightly wider right side top hat spacer, which is
36-31-2-301-737. SOME 4.00 rear tires are quite wide (especially Enduro types)! If your rear tire is touching
either the swing arm or the brake stay at high speeds, then you almost surely will have to use a wider spacer.
That TOPHAT spacer I am speaking about is located in the RIGHT side of the rear wheel of twin-shock
absorber bikes & is easily removed & changed. The wider spacer may not be needed on 1981 & later, but I
HAVE seen it required. There is a VERY MUCH wider spacer available too, see earlier in this article.
The stock spacer is 9.2 mm wide, the 36-31-2-301-737 is 10.7 mm wide. On some bikes, with some tires
(Continental TK17 in 110 was the worst I have personally tried, other than enduro tires in 4.00), the tire will
rub the swing arm at high speeds (~85+), the spacer was a must....unless you liked the rubber smell, etc.
Usually most 110 tires fit without needing the spacer, say on an early eighties RS/RT. On some rear disc
brake bikes with the rear tire being a 120, I have had to ADDITIONALLY put a spacer on the left, a common
very large washer called a Fender Washer, available at most hardware stores. Strangely (or not) that has
mostly been when using an EARLIER snowflake wheel. These snowflakes can LOOK the same, but are NOT.
That spacer moves over the brake stay very slightly...avoiding any possibility of tire rubbing at speed.
The swing arms vary a bit, even in the 1980-1984 era, another reason for sometimes needing the spacer(s).
When you change the right side tophat spacer to the longer (wider) one from BMW, that does move the
wheel-spline-engagement very slightly to the left....by about 1.5 mm, which is a small amount. There are
naysayers that think the wear on the rear splines will be such that you cannot go back, and that is not really
so over the long run, nor does the tiny shortening of the spline engagement have any large bad effect on
spline life. Changing the tophat spacer does NOT affect bearing preload.
The snowflake rear wheels on the RS and RT are slightly wider in rim width than the drum brake models.
The disc brake snowflakes are 2.75" rim width (measured at the official point for tire contacting the rim);
and the drum brake snowflake rims are 2.5". This slight 1/4" difference also makes the RS/RT disc braked
bikes rear tires a bit wider...and puts a bit more rubber on the road too.
Don't forget that the under-seat and owner's booklet values for tire pressure are TOO LOW for modern tires.
Try about 33-34 psi front and 38-42 psi rear.
21. Bridgestone tubes are of good quality.
22. For TUBELESS TIRES being used on TUBE TYPE RIMS, the rim hole is 8 mm. If you do not wish to enlarge
the rim hole for a standard pull-in type of stem, then there is a special valve stem that is available, even from
BMW, that seals at the inside of the rim by means of an O-ring built into a recess of the stem unit. The
stem area of the rim, inside, must be machined flat for this to work well.
This section was added to try to explain things often poorly understood...if at all...about such as tire
profiles, sizes, differences in construction, warming-up effects, differences between road, track,
and racing tires, etc. Some of this information came from Harriet Ridley, a moto-writer in U.K.,
but the information has been added-to, deleted, subtracted-from, edited, etc., ...by me. So, if you
see some familiar wording or sentences, they might be attributed to Harriet:
Some of what you read below is very basic. READ IT ALL!
Tires work with your motorcycle to determine how hard you can brake, how fast you can accelerate and
how much you can lean and how well they keep you from loosing control. The tire and how you use it
which includes inflation amount, determines how far you can travel before they wear out and let's face it,
tires aren't cheap. There's no optimum tire for every situation. Each tire is a complex trade-off between grip,
longevity and handling.... and R&D is poured into finding the perfect compromise for a given situation. With
three aspects responsible for a tire's characteristics - compound, carcass and profile; besides, of course,
inflation pressure and road conditions including surface and temperatures; - there's a lot for engineer's to
If a tire were made from pure rubber it would wear EXTREMELY quick and would never take the required
weight. Instead, the 'rubber' (often a synthetic equivalent) is mixed with carbon black to make it tough and
resilient, then baked at high temperatures and mixed with what could be dozens of chemicals and even
silica/sand. Varying quantities and types of these determine the compound's softness and its optimum
operating temperature and its wear.
The tire grips by pushing itself against the surface so the softer the compound, the more it will grip. The
softer compound will also be more abraded by the road, wear faster, as well as generate more heat by
Regardless of compound, there's a temperature at which tires operate best for the purpose they were
specifically designed for. Unless a tire reaches its optimum temperature the compound won't soften
enough to provide the intended grip - hence the use of the silica in road compounds to ensure a certain
level of grip in cold, damp conditions and why it is important to warm up your tires carefully. Silica can
also INcrease tire tread life. There is also a temperature at which all tires will overheat. After
construction a tire is cured in an oven at a certain temperature for everything to stick together. If your
tire goes over that same temperature for too long, it will de-cure; at first it squirms and loses traction
as it breaks down chemically, then it delaminates as it breaks down physically. So each tire is carefully
tailored to suit its intended purpose.
The compound is designed for plenty of grip at constant, high temperatures
reached by the extreme pace maintained on a track: hard acceleration, hard braking and high corner
speeds. Because it is designed to live at high temperatures the race compound will also take longer to
reach its peak. If you use these tires on the road and even if you ride quite hard, you'll be forced to
slow down for traffic and stops, etc., and every time you do so the tires will cool off and take a long
time afterwards to even approach their required temperature again. Keep this up and the tires will wear
fast and shed rubber through cold tearing; so they may look like they're being used hard, but in fact
they're disintegrating from misuse.
Each time a tire goes from hot to cold it IS re-curing itself to become harder, as
chemical oils used in the tread to maintain compound are released (hence, in some cases, the blue
color you sometimes see on a tire's tread after hard use). While this is minimal on a road tire, it
becomes more extreme on race compounds. Specialized race tires are designed to go through only
one heat cycle before compound deteriorates, while track-focused tires are a lot more sensitive to
heat cycles than their road equivalent. Hence tire warmers not only bring tires up to their required
temperature, they also maintain a constant temperature between races or sessions to minimize
heat cycles. ROAD tires are designed for all the heat cycles you might need.
The carcass gives the tire its required strength; it's more resilient on a road tire & how
much the carcass lets the compound flex affects heat generation) and its rounded shape. But
because the tire's contact patch is flat the tire has to compress & distort where it meets the ground.
This shape-changing means some of the rubber has to slide across the road to achieve the new
shape, causing wear, while the constant flexing of compound & carcass at this point generates heat.
The old-style cross-ply tires used many layers of plies molded at an angle to give the tire strength.
But the sheer amount of material used made them heavy and generate a lot of heat, so harder
compounds had to be used to maintain the right temperature.
As bikes became faster, lighter and more agile, tires had to follow suit. Bias-belted tires appeared as
a step on the path to radial heaven, and they're still in use on big heavy bikes where sidewall stiffness
is more important. But radials broke new ground thanks to clever layering of fabric. A radial tire is not
only lighter and more responsive, it also runs cooler as the tire distorts more easily, a special type of
distortion and angle that seems to be opposite than flexing increasing heat that I have previously
described (and with running tubes). Running cooler means you can use a softer tread for better grip
with no increase in wear. The shape of the carcass's crown radius also dictates the way a tire handles,
which together with the sidewall determines profile.
On a 120/70-17 front tire, 17 is the diameter of the wheel rim in inches, measured at a
particular point of the sidewall area of the wheel; 120 is the width of the tire in millimeters, and 70
is the percentage height of the sidewall against the tire's width - so the sidewall is 84 mm tall. The
higher the sidewall, the more slower steering but good stability. Lowering the sidewall by 10mm to
a 120/60-17 the tire acquires a steeper profile - it is more 'triangulated'. The results are quicker
steering and more grip when leaned over, but anywhere in-between straight line and transition from
upright to lean angle is less stable. The carcass's crown radius also shapes the profile.
The sidewall also acts as suspension for the tire and comes in varying degrees of stiffness: a big
heavy touring tire needs the thick bead filler found in the sidewall of touring tires for added strength
and stability. By reducing the height of the sidewall, the tire is less capable of absorbing surface
irregularities and tends to hop when cranked over, causing the bike to understeer. A race
chassis with high quality suspension copes well with a quick-steering 120/60 or a racing
slick's more radical profile and flexible sidewall, but fit racing slicks to a road chassis and
the bike becomes un-settled. As a result road bikes and Superstock racers would generally
opt for the more suitable 120/70 front tire.
Rear tire size also affects performance: a 180 section will steer quicker, while a 190 will last
longer by coping better with power battering.
A road tire will greatly outperform a race tire in terms of acceleration, cornering speed, braking,
durability and stability ....over the course of a road trip.
A tire's compound (tread) is molded onto the carcass. On a radial tire the
carcass is typically made of two plies with strands usually of steel or aramid (that's Kevlar):
the first is a radial ply that runs at 90° to the tire's rotation (folded under the steel bead),
while the second runs in the direction of the tire's rotation to minimize expansion at speed.
The top two plies are cross-plies (with usually Nylon strands) placed at an angle to add strength.
The bead that you'll find on all types of tires holds the tire to the wheel rim with a 'rubber'
bead filler to strengthen the sidewall.
• Low pressures cause tires to move around and generate heat, while high pressures will reduce
the contact patch and the tire will struggle to warm up. Always check your pressures from cold
(cool to baby bottle temperature). NOTE that many manufacturers, due to lawyers and thread of
lawsuits, will simply repeat the motorcycle manufacturer's recommendations for street riding tire
pressures; BOTH of which can be WAY wrong for YOUR tires and riding. WAY WRONG!
Typically and generally, the real tire pressures you should use for street riding on OLD BIKES
will be HIGHER than the manufacturer says. This is especially so for such as early Airheads,
which used the old soft and ribbed tires, like the Continental RB2/K112. For modern tires,
pressures under 30 or slightly over 30, will be QUITE WRONG for best handling...and life too!
You will probably find that your bike that was specified for those tires, say 4.00-18 rear and
3.25-19 front, should be run at 33-36 front, 38-42 rear, depending on speed and loading.
• New tires need careful scrubbing in to get rid of the slippery mould release agent used at the
end of the production process. Some say up to 200 miles. MY experience is that 50 miles is
more than good enough, but if you scrub the tire after it is mounted and inflated, with soap and
water, then flush it off, you can go do less. Just be particularly careful during initial 20 miles,
and be sure your break-in miles include some steeper turns....head into them gently until the
tires are scrubbed in!
• A slick's uninterrupted compound (or tread) optimizes dry grip, but it's unable to clear standing
water and debris. Hence a pattern is molded into a road tire's tread. A tread pattern also generates
heat by flexing ('block movement') and is usually no more than 8 mm deep to prevent weave and
excessive heat build-up. Mind what I have said about depth and tire rating (V, H, S...) much
earlier in this article, and tire mileage.
• Race tires are available in different compounds and mix-matching can provide an ideal compromise
between grip and longevity. A softer tread is used on the front for better grip while the rear gets a
harder compound to cope with the power battering. The front is also sometimes fitted with a flatter,
more stable profile while the rear can be more triangular for quick steering. Manufacturers do
all the work for you on road tires so don't mix-match on them, unless you know what you are doing.
• Specialized race tires get different compounds on either side of the same tire, so where a track
has a predominance of right-hand corners the compound will be harder on the right but softer on
the left. Similarly, Bridgestone's dual-compound road tires get softer edges for good corner grip
with a harder middle to reduce tires squaring off with the accumulating non-cornering miles.
01/28/2004: initial 'dated' upload after final revisions.
02/03/2004: expand information on handling and tire size uses slightly
02/09/2004: add #14
09/01/2004: Update article, with better clarifications and stem part number, etc.
04/03/2005: changes in emphasis throughout, and add some hyperlinks and add #15
04/20/2005: Add tire make and model description information in more depth
05/13/2005: minor updates, primarily on the top hat spacers.
08/07/2005: add comments on karoo and scorpion and info on Discount m/c tire and acc.
08/13/2005: update section 4
09/24/2006: add 17
12/15/2009: revise & add more tire model information
05/12/2010: Revise for clarity, combine some areas, add more information to what is now 23.
05/31/2010: Add 24.
12/22/2010: #25 finally added/updated.
12/23/2010: updated tire recommendations
03/14/2011: add #26
06/20/2011: Finally got around to updating my recommendations for dual-sport tires
06/28/2011: Add more information on tire flexing, contact temperature, use with tubes
08/04/2011: Correct my math on hydroplaning, add a bit more to that info too; combine into one place.
04/25/2012: Update tire information slightly, clarify minor things here and there
06/17/2012: add Bridgestone tubes; and, update vendors
07/11/2012: Minor updates on Roadrider tires and add 28
10/14/2012: Add QR code, add language button, update Google Ad-Sense code, minor other things such
as updating URL in #24. Language button removed later, as had scripting problems with it.
01/22/2013: Updated article to give more information, in depth, on tire types and uses, its own section.
04/23-24/2013: Minor updating, tire pressure reference, etc. Edit to reduce SOME duplication &
improve clarity at various places.
09/20/2013: Add Conti-Attack listing & info.
10/07/2013: Add tire photos, and a few comments here and there
04/08/2014: Update the entire article. Fix typos, add information, fix numbering system, etc.
04/23/2014: Update various places. a bit more 09/25/2014
11/02/2014: Add link to #5
05/24/2015: Add note to Avon RoadRider's. Additional note regarding steel plies pros/cons, on
05/25/2015 & 06/12/2015. Testing notes on 06/19/2015 & 06/26/2015.
10/02/2015: Updated for extensive testing on Roadrider's.
11/04/2015: Updated for clarity.
11/14/2015: Heindenau review. Clean up article some, with fresh formatting, more concise statements,
on 11/20/2015, & additional notes in late November. Incorporated my notes (I'd misplaced
them) for my Michelin tests....found them stuffed into one of my 10,000-pockets-riding-jacket.
12/11/2015: Increase font size to 14pt, finalize changes to meta-codes, clean up due to font changes.
01/21/2016: Some updating, due to changes in comparo methods; to bring article more in line with the
improved performance of the latest tires.
© Copyright, 2014, R. Fleischer
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