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Tire Repair, Pressures, Sizes,
Rims, Vibration/Thrumming,
Studding, Mudflaps.
Tube & Tubeless type tires.
Fitting various sizes of tires. 
Copyright, 2013, R. Fleischer
http://bmwmotorcycletech.info/TireRepair.htm
Article # 54....section12
 

 

You may be interested in reading this:
http://bmwmotorcycletech.info/section5.htm

 


How MOST tire punctures/flats occur (maybe!!):

I am not sure of the accuracy of the commonly held belief that the front tire "sets up" road debris for rear tire punctures.  I think it possible & would be ONE reason the rear tire always gets more punctures than the front.   I think the MAIN reason is because the rear tire is the POWER applier; hence produces MUCH more force to things in the road.  I have seen arguments that the use of a mud-flap on the front will 'reduce' punctures. THAT may also be correct.  A few think that a mud-flap on the FRONT OF THE REAR FENDER also helps SOME, if it sticks down enough. That is not very easy to accomplish properly on some bikes, as the rear fender is not necessarily part of the wheel unit.   I think both flaps MAY HELP.   I have found nothing but anecdotes; no definitive testing on how/why/details punctures occur. If there is such testing, I'd be interested in looking at it; so let me know.    http://bmwmotorcycletech.info/emailimage.htm

I suspect that more than one tire company has done testing in this area; but have not looked in some years for it. I once tried to find out, from two tire manufacturer's, and did not get much useable information back from them.

It may be a combination of things, and that is what I believe.  Various discussions & arguments put forth (some by me!) have included weight; the high pressure-point contact of the rear tire when the motorcycle is accelerating; the fact that the rear tire slips a lot even in cruise, even when not accelerating; etc.  My own belief is that punctures primarily are a combination of the front tire 'sometimes picking up debris', but probably (??) the phenomena is PRIMARILY the driving & also when accelerating forces at the point barely ahead of the major contact area, that is responsible for flat tires.   As you ride, power-on just to maintain speed, and worse when accelerating, this causes the rear tire tread to deform, and that helps to strongly pick up the debris and force it into the tire. A factor with this particular idea is that low tire pressures probably increase the likelihood of flats, & many do not check tire pressures regularly.

Until I get some sort of definitive answers/replies from motorcycle tire manufacturer's or others who have actually done testing, I leave my speculations...or at least ideas.... for you.   Meanwhile, don't ride in the middle of the lane, don't ride on shoulders of the lane, and keep your tires inflated...and INSPECT THEM regularly.  A fair amount of flats occur from nails, etc., that have been in the tire for some time.  Install mud flaps, at least at the rear of the front fender.

IMO:   A tubeless tire that does NOT use steel strands in the tread is more likely to have a LASTING on-road repair from use of sticky strings or internal patch, or certain types of external plugs.  This is particularly so if you are using such as the Stop'nGo slippery mushroom type of plugs, which require a lot of reaming of punctures in steel belted and steel ply tires.  The Avon Roadriders, as ONE example, do NOT have steel plies.  Conversely, that makes them POSSIBLY more conducive to punctures...perhaps offset by somewhat less likely the tread would be punctured.


Getting a rear wheel out, various methods:

(a)  Bike on center-stand at curb, rear wheel hanging over curb.

(b)  Bike on center-stand. Tie center-stand to front exhaust crossover pipe. SECURELY. Use extra strong bungees. USE TWO to be safely sure of no problems!   Remove front wheel. You will have to undo any disc brake caliper(s) that prevent the wheel from removal.  Hang caliper(s) via a bungee, NOT by the hose, which could kink the internal tiny hydraulic plastic tubing, and ruin the hose.  Put gloves on ground.  Slowly tilt bike forward, so forks rest on the gloves.
You now have the rear end of the bike WAY up in the air, and PLENTY of room to work.  

(c)  You may find that the wheel does not come out, even on an angle, unless the front end is lowered, or the center-stand is used with a board underneath it.  This is common if you have a Reynolds Ride-Off center-stand...put a board under the center-stand.  It is also common with an oversize front tire.   If you are careful, you can remove the wheel all by yourself by tilting the bike a bit to the right, while getting the wheel out.   It helps if the tire is fully deflated. Some have gone so far as to lay the bike on its right side.

If you have tubeless tires, you probably will repair the flat tire temporarily with a plug of some sort.  You could also consider removing the wheel & inserting a tube.  An internal plug/patch on the inside of the tire is the proper permanent repair.  Use your best judgment on this.  Sidewall repairs almost never hold up. You are not really suppose to ride at any speed with an external plug. Steel cords, in tires containing them, can cut inside or outside plugs, over relatively few time/miles.  

For serious work, such as repairing a tube, or installing an INternal patch/plug, breaking the bead is necessary; OFTEN NOT EASY.  You must have the tire totally deflated.   You can try the weight of one side of the center-stand; or side-stand; I think those things are iffy for most riders.   I prefer a real tire bead breaker. You CAN carry a multi-piece bead-breaker, that assembles easily, and usable by the side of the road.  I suggest the following product, and it is a LOT better than the modified C-clamp that I used to carry, all-things-considered:  http://www.bestrestproducts.com/c-98-beadbrakr-tcm.aspx


Tubes, conversions, tire sizes, hints:
The purpose of the single outside valve stem nut is to help with installation of the new tube.  After installing the new tube & inflating the tube/tire (making sure the stem is sticking straight, not angularly out), the nut can be thrown into the junk box, thrown away, or moved up against the cap.  I never throw anything away!...unless totally, forever, worthless!  Just do NOT have that nut down against the rim.  If it is against the rim, & if the tire should shift on the rim during a serious flat situation, the tire could try to rotate the tube.  Having the nut at the rim does not allow for ANY tire/tube movement.  Be sure you use a lot of tire talc on your hands and all over the tube and inside of the tire.  

Some folks have modified the 8 mm hole in the snowflake tube type rims, to 11.5 mm, and modified the inside area too, so that larger tubeless stems can be fitted for using tubeless tires without running tubes. Flattening the inside of the rim at the hole area by machining may be needed.  There are also metal stem types available that fit the smaller original hole, but definitely need a flat inner surface, and I think that type are preferable.  BMW and others sell them.  More on them later herein.

If you have a hole size conversion involving a larger hole & then revert to TUBES, DO NOT use RUBBER to seal the inside.  Use a metal washer, shaped properly.  Use of rubber could cause the tube to not eliminate trapped air between the tube & tire, causing chaffing of the tube.     SOME have cut off a 'rubber doughnut' by modifying an old car-type tubeless rubber stem.  They then use the rubber piece to seal the m/c tube at the rim, with a washer & nut.  This works, but keep in mind all caveats. 

Ultimately, anything done besides the original stock method means you are on your own, safety-wise and performance-wise.


REAL tire talc (no oils in it) and REAL tire vegetable based lubricant (thin it per instructions) are available from tire distributors and auto repair stores.  You might want to obtain some 6 or 8+ ounce flip-tip plastic bottles like used for certain hair and other products, and have some talc in one, some thinned tire lubricant in the other, and keep them on your bike with your big C-clamp or bead-breaker or whatever you use to break the bead from the rim.  I have kept a spark plug hole type of compressor adapter, patches, spare rear tube (front one too on LONG tours) on the bike.   Some (me too!) may want to use the guts, modified slightly, of one of those cheap CHEAP 12 volt compressors sold at WalMart, etc.   They DO work just fine.  I LOVE those modified 12 volt compressors. Versions using the same Chinese pump are available from bike shops, etc. at a considerably higher price.

ALWAYS replace tubes when replacing tube-containing tires.  SOME say to never patch a tube, only use new tubes.  I have done both, but replacing a tube anytime the tire is demounted after the tire has been on the road, is probably the safest thing to do.    The best tubes are natural rubber based, and these resist long tears/rips better, but they also are slightly porous, so they leak, although very slowly....another good reason to keep an accurate tire pressure gauge in your tank-bag, or wherever on the bike. BTW...There is a lot of confusing information about Natural Rubber tubes and those 'not so'.  The truth is highly mixed-up, and both the Natural and Butyl/other tubes just vary in their percentage of ingredients. BUT, the one sold as natural rubber types ARE less prone to rips and tears.   I recommend you NOT use super-thick competition tubes.   There ARE several reasons to replace a tube when replacing a tire, REAL REASONS, including a used tube being weakened by use.  A used tube will NOT fit weakened areas into the same 'grooves', on the inside of the tire, ETC., that it did on the first tire.....thus, INCREASING the chances of having a rather goodly sized tube failure.  That type of tube failure is USUALLY NOT REPAIRABLE.   The inside of a tire may or may not have those ridges, and the type of tires withOUT ridges is probably a bit less likely to keep a tube from rotating slightly upon a serious flat.

Almost all tires marked as TUBELESS are actually OK to use with tubes.  If not sure, ask your tire distributor, although many motorcycle places that sell tires know almost nothing about the finer details.    This generality about tubeless usage is NOT necessarily true...but can be.... for radial tires.   Yes...there are now some radial tires designed for old classic motorcycles, even some in sizes that will fit your Airhead.  Tubeless tires containing tubes should be speed limited...to less than the tire rating.  The rule of thumb is to reduce the speed rating by one position.  This is because adding a tube causes more heat from flexing.  You also can expect tread life to decrease with a tube. There seems to be some evidence that using a tire withOUT a tube on tube type rims will extend tire life, due to less heat buildup.  BUT, zero information on if performance suffers due to the possibility that the tire does not operate in the designed temperature range.  I think all of this highly speculative and can mostly just be forgotten.
...or tucked into the 'around the campfires discussions'. Or, see next paragraph too.

Some have run tube type rims with tube-type tires, where the tires seem to be inside-sealed well enough by the tire maker, to not leak, without tubes being used.  I have some preliminary reports that tires are getting better mileage than they did with tubes.  You are on your own if you do this sort of thing.  There is an extensive article on the subject of tubes, tubeless, usage on tube type rims, on this website:  http://bmwmotorcycletech.info/section6.htm

It is not commonly known that H rated tires MAY last longer at reasonable speeds & loads, as compared to V and higher rated tires.   This is especially so with the same make and model.  Sometimes this is purely the result of the lower rated tire having DEEPER tread! Deeper tread squirms more, and generates more heat, so for higher speed rating, the manufacturer may reduce the depth of the tread.  So you MIGHT have the situation of purchasing a high speed rated tire for whatever reason (not speed!), & find out it costs more and lasts less! 

Even slightly larger tires or tires of different profile ratio will change the handling of your bike, you may or may not like the difference. You may or may not even notice the difference.  In some cases a larger front tire in a fast handling type, the Metzeler ME33 is an example here, will revert to more stock-like handling, but last longer, and even handle better when pushed hard, than the smaller size. Improvement by using a slightly larger tire is NOT a universal thing to be expected!  Typically, the handling is decent if the front tire is up one size and same for the rear tire. Tires may then last longer too.  DO NOT always expect more 'grip' from a larger tire...that may not happen, mathematics & testing proves it.  For the rear tire, increasing the size may help with load carrying ability of the bike, but going too far may cause the rear end to effectively change the front end handling too much for your liking.   

Some early Airhead front fender braces do not allow for wider than stock size tires, and a later brace may work. This is a COMMON modification. 

BMW has shipped tire rims with rim widths from 1.85 to 2.75 inches for the tube-type Airheads.  Some tires are too wide for fitting, safely, to those rims, and the tire might have an excessive rolling tendency in cornering.   Don't try to measure a tire rim, there is not a quite specific place you will see for doing that.  Don't believe me?....then, next time you remove a tire, look on the rim for the width size...and then try to figure out just where the measurements were taken. 
 

A larger tire may not fit the rear swing arm.  A spacer may be required (BMW does sell them for this purpose).  On the Airheads that specified a 4.00-18" rear tire, generally a 110 rear tire will fit, 120 may or may not, and the same for 100 on the front. 

Tires expand in WIDTH as speed rises.

Front tires of 90 or 100 section or 3.25 or 3.50 are quite usable (handling will change somewhat). Same with rear tires of 4.00, 110 and even 120 section, on all the earlier Airheads that came with 3.25 front and 4.00 rear.  SOME 120 tires are too wide to fit without rubbing.  Often the rubbing occurs only at high speeds.    The 10.7 mm wide spacer (stock is 9.2 mm) used at the right side of the rear wheel, part number 36-31-2-301-737, is usually not needed on 1981 and later twin shock models, when using the 110-90 x 18 tire, but sometimes it is with the 120-90 x 18 oversize rear tire; especially with 1981+ models.  The 110-90 x 18 rear tire fits most Airheads.    Unless you have real reasons, such as very high loads, the 110 size tire is likely the way to go if you want a metric tire instead of a 4.00 inch tire.   Rear tires usually must be fully deflated, and messed a bit with, to remove or replace over the brake drum rear ends; sometimes with the disc brake rear ends, even though the caliper can be moved out of the way.   It can be helpful to cut the rear fender sides on a smooth curving angle, from the license plate area up and forward, to help tire removal.  Those with /2 bikes with hinged rear fender may smile at reading that.   Comments about the 129-90 x 18 tire rubbing the swing arm do NOT apply to the late model Monoshock RS and RT Airheads, after all, those bikes were designed for that size tire (they also use 2.5" rims, not 2.75" rims, like the twin-shock Airheads do for the older RS and RT). The 120-90 x 18 size tire works best on the wider 2.75 inch rim used on the RS/RT models (typically 2.75 inch marked rim or "C" on disc brake models). But, that brings the tire closer to rubbing.  The 120 tire will work on the 2.50 rim on the drum brake models. I do recommend that you use the stock size tire, or use a 110, instead of a 120.   It is probably better to use a 110, unless you know and for some reason insist on a 120; know the 120 will fit OK and not rub the driveshaft tube, nor perhaps the disc brake stay....at speeds of 85 mph this has been known to happen, even on later 1981+ bikes not needing the wider right side spacer.   If you have to move the rear wheel to the left with a wider right side spacer, you MIGHT, in some situations, need a flat washer between the disc brake caliper cast holder, and the left side top hat spacer, and might have to play with the brake stay a bit.  This is very simple to do.  Be sure to read NOTE 27, below.

For instances of tire interference, at rest or at speed, the 'disc brake stay' can be easily offset, and a washer used between disc casting holder and the left side of the wheel.   It may well be best to just use a 110/90 size tire, only a very FEW 110 are too wide to fit all the Airheads. 
There ARE some 4.00-18 tires that will not fit the rear twin-shock swing arms, these are usually Enduro tires; but often can be made to fit by using a wider top hat spacer of some sort on the right side of the rear wheel, that is even wider than the -737 spacer mentioned above.  There IS a wider spacer available, you will find information in the following article:   http://bmwmotorcycletech.info/wheels.htm.  Since the twin-rear-shock models have a splined coupling at the rear drive and the wheel cup has splines to match, change to a wider spacer, or vice-versa, may concern you.  Unless there is a very large difference in wear, you can disregard this.  You may not notice the difference except in possibly longer wear with a larger than stock rear tire, but there is also the situation where the rear tire wear flattens considerably.  A flat-worn REAR tire is THE most COMMON cause of high speed INstabilities...REALLY!!
 

On the front, the stock 3.25-19 tire can be substituted by a 90/90 or 3.50 or a 100/90.   SOME oversize front tires will not fit due to fender/fork brace interference (later braces were wider, & can be fitted), but other airhead braces or modifications can be used.  The larger size tires generally give a more stable feeling, but are not quite as quick handling.  Remember that tire profile varies with size. In some cases, such as with a Metzeler ME33 tire, which is quicker handling due to design, going to an oversize front tire seems to make the handling exceptionally nice.  After 1984, in general, the stock size tires seem to work best.  

NOTE!....the classic BMW handling is had ONLY with the exact original brands, sizes and styles of  tires.  This statement includes that you have original shocks, springs, ETC, in good original condition.


Removal and replacement of tires is VASTLY easier if the old and new items are placed in hot sunlight and allowed to heat up considerably.   It is very helpful to have THREE tire irons, two can be the standard shorter ones from BMW, and one should be the longer available BMW one.  Tire lubricant is a MUST.  


Do NOT pry on wheels with the discs laying on the ground...discs must NOT have pressure placed sideways on them. 

Gasoline is NOT an appropriate tire lubricant, and neither is common soap, saddle soap, nor anything else (well, almost....'personal' lubricants, water-based, are OK).  REAL tire lubricant is a vegetable product, made from FLAX, and is water soluble.

 


Balancing...yes? no?
MOUNTING.
HINTS.

Whether or not tire balancing is any big help, meaning worth doing, especially if you are paying for it, is debatable.  It certainly is worth the effort and cost if the assembled wheel/tire is quite far out of balance.  It almost always is helpful for moderate to high speeds.   The truth is that the better brands USUALLY have tires that are quite well balanced as they come to you, although they may have color markings for the best balancing use.  Those who do a lot of miles and do their own tire work WILL want to invest in a tire balancer.   Some no-cost one's can be built, and one of many such types is described on the http://airheads.org website,  but something like the Telefix balancer may really be worth the money.  The tire balance mark, usually a color dot, goes next to the valve stem.    If two dots, usually the red is the balance point.   There are 3 hole, 4 and 5 hole adaptors available for the Telefix balancing stand for the single rear shock airheads and K bikes. The truth is, that balancing can help, can certainly weed-out (or fix) badly made tires, compensate for imbalanced wheels; ...BUT.....you may want to THINK about the costs, although quite low or moderate, for you to own balancing tools, versus your tire seller/installer/etc., charges for adding balancing.....versus your type of mileage.  You may well want to consider your labor involved in changing and balancing your own tires, tires you purchase directly.   I prefer to own and use tire balancing equipment.   I prefer the Telefix stand STYLE;  a picture of that stand is in Anton's, below linked article, but the stand has the Metzeler name on it.  In fact, my old Telefix stand was purchased from Metzeler!  Metzeler probably no longer sells them..???

For Classic K bikes; Monoshock and Paralever Airheads too; I have, for a long time now, used a Telefix type of stand and an adapter that fits the wheel. I have a thinner "axle" with cones, for use on the Airheads that are twin-shock type. That thinner axle is still larger and more beefy & does a better job, than the Harbor Freight item, which also does not have the nice movable and rotatable cones. 

One thing seldom talked about is the true/actual NEED for balancing wheels/tires. As I noted, above, most motorcycle tires seem to come relatively well-balanced. I have found this particularly-so for some brands.  Once in awhile there is one that is quite far off. HOWEVER, seldom do I have to use over 30 grams of balancing weights.  My testing was on a very smooth road, at slowly increasing speed, noting where vibration is, and is not. I would also do sudden braking at various places I felt any vibration (or HEARD anything, like thrumming), as the braking can bring on an oscillation that might not be felt otherwise. Now and then I would test on bumpy high speed roads.  I just can't flat out tell everyone that they "must" balance wheels and tires. My testing on a number of various bikes and tires, tubed and not, just does not give answers that are definitive, yes or no, on balancing. SO.....I think that for most folks, whether or not to balance the wheels and tires, is not all that cut and dried.  I do know a few folks who are very anal about how smooth they can make their motorcycles.  These folks purchase quality tires (such as by Michelin); maintain their bikes well, and always balance their tires.....and they RE-balance the tires after they are well-broken-in (yes, tires can change balance after they have been in use....they tend to do this only once...).

Here is an edited version of something I posted to the IBMWR.org tech list:
Anton Largiader put a page on his website http://largiader.com/balancer/ discussing SEVERAL of the various balancing methods, applicable to K and Airheads too, and there is certainly even more information available in the ibmwr.org archives and other articles you could find. Anton's site has dimensions for some adapters, etc. You can also purchase balancing equipment such as a stand, a round 'axle' (and cones for Airhead jobs), and an adaptor that fits 3, 4, and 5 bolt wheels. I think, considering what dealers charge to install and then balance tires, that a really proper balancing stand will pay for itself rather soon if you ride much. There are some simple methods using string, etc., that work, but in my experience they are not as good....AND, FRANKLY, I find them a PIA to use, compared to the real stands types. I have used a motorcycle type high speed balancer in my BMW shop, but found that it did not work much faster; was NOT hardly much better in actual on-the-road tests, as the static Telefix stand type.  I ended up selling it.  A long time ago, Harbor Freight sold an adaptor for use on its own balancing stand, applicable to other stands too, but the adaptor is NO LONGER available from them; it was also a bit crude in the hole threading, but quite usable...especially if you re-tapped the holes (just insert a metric tap, to clean the threads. For the curious, in case they find one someplace, heck, even at an old Harbor Freight store, the adaptor was 98490, for 98488 stand, and the adaptor was 3-1/2" in diameter, 1-3/4" high, and had 8 each 1/2" mounting holes, so spaced to fit most all of the wheels. The center hole was smaller than the Telefix adaptor (the Telefix used a larger rod as axle), but the hole diameter could be changed on a lathe to fit whatever size "axle" you use with your particular balancing stand. Note also that the bolts used with the Harbor Freight adaptor had the cones pressed onto the shank tightly. Two additional threaded holes were in the Harbor freight tool, enabling a bit more versatility for various wheels (3, 4, 5 holes). The Telefix, part number 65.10.01.12, was a nicer-made item than the Chinese-made Harbor Freight adaptor, as you might expect; but fit only the older 3 and 4 bolt wheels.  It is possible that you can now purchase adapters for any wheel.   I VASTLY prefer the Telefix/Metzeler/Handy/etc. brands, over the Harbor Freight product.  You< will find they do a better job, too, and no axle bending, poor fitments, etc.

MOUNTING:

Motorcycle tires MUST be mounted concentrically. If not concentric, the motorcycle will vibrated BADLY.  Motorcycle tires are manufactured with a concentric ridge line near the bead, on both sides of the tire (check both sides!) so you can easily see if there is equal spacing all around, using the rim edge as a guide versus that concentric tire ridge line.   It is a PIA to have to demount the tire if it is not concentric and the most common cause for that is failure to use a lot of proper tire lubricant during assembly, AND have a quite smooth rim...you MUST clean and then sandpaper the rim and clean it again if not smoooooth.......with a secondary causes being too slow of inflation.....I will get into THAT later in this article.    Wet the lubricant or add more if it starts to dry out.  When you are done, wash the tire.  A new tire should be VERY thoroughly washed with common soap or dish detergent mixture and a stiff brush & hosed off really well.  NEVER ride very aggressively, especially in cornering, on a brand new tire; rather, allow 50 miles or so.  If the tire was vigorously washed, the mileage for this can be reduced some....but break-in is NOT just tire cleaning.

It was not all that long ago that tire manufacturer's generally did not want you using over perhaps 50 psi to seat the bead.  Most will now say a maximum of 50% over the maximum pressure molded into the sidewall.  Even with lots of tire lubricant, I never go over 60 psi.   Going very much higher than 60 CAN BE QUITE dangerous, although BMW themselves allowed 67 psi in a SI bulletin.  Be careful, use safety equipment & I recommend you DO NOT go over 60 psi!   Use LOTS of tire lubricant on the tire bead..... that must be on a CLEANED & SMOOTH rim...and everything HOT from being in the sun for quite awhile. The tire expands a bit in the sun, helping immediate inflation seating...but, also, the tire MAY continue to move slowly upon the rim, seating itself concentrically, after several minutes of sitting in the sun, well-lubed, inflated....so be patient, and ..again...the use of proper tire lube is a BIG help (flow the lube onto the bead during the initial assembly & during the inflating).   Occasionally you must demount and remount a tire.....but this is VASTLY less often if  you use my high flow inflation techniques with proper preparation of rim bead cleaning...and proper tire lubricant.

TUBE tires:  Once the tire is fully inflated, and the ridge lines look concentric on both sides of the rim, the tire is fully seated at the bead, it is a good idea on tube-containing tires to THEN FULLY DEFLATE the tire (it will not come off the bead-rim), bounce it a bit (upright, turning it & bouncing a few times in different spots), and then re-inflate it to NORMAL pressure; or, to maybe a few pounds extra, to allow for settling-in over the next day or so.  ONE of the reasons you got your hands full of tire talc and rubbed it all over the tube outer surface and the inside of the tire, is because bouncing, deflated, will tend to let any tube irregularities inside smooth out when you refill with compressed air.

HINTS & SECRETS: 
Many a person has tried to get a tire, properly located in the middle of the rim, to fully seat to the rim and EVENLY all around during inflation... without success..., even after lots of real tire lubricant, and even with the tire/wheel/...and tube, if using a tube....all being quite hot from sitting in the sun. Many modern tires are quite difficult to bead-seat.  There are secrets to nearly 100% of the time always getting your tire to seat its bead properly.  Many of you will not have the proper equipment.  But, I will make some recommendations below that really DO help:

The compressor should have a substantial tank, 5 gallons or more being fine, 2 or 3 might be OK.  Have the air tank filled to 100 to 125 psi, or whatever your compressor can safely do over 100.  It is important that the air chuck NOT HAVE its CENTER PIN, you need to remove it!   That allows a FASTER flow of air from the chuck.  Even more important to ensure a FAST flow of air is to REMOVE THE TIRE/TUBE VALVE CORE.   Doing these things with a well-lubricated tire, and a very well smoothed and clean rim, and with real tire lube, will ensure the tire snaps into full concentricity NICELY!  You will have to hold the pin-less chuck against the tire stem while you quickly open the air outlet valve on the compressor.  It is the SPEED at which you inflate that is so important (assuming a lubricated hot tire).  Having the tire and wheel in the sun, and thus HOT, is also a BIG HELP.  In some instances, you may have to drill out the pin-less chuck, or change hoses to a larger inside diameter, etc.  Check your equipment for every place that the inside diameters might be too small.  These things have become THE answer in my shop to inflating even difficult to mount tires, so they are fully properly concentric.   If you are using an extremely long hose, certainly that is if in excess of 25 feet, then get a shorter one, and, again, get one with a large internal diameter, and the fittings should also have large diameter holes.

The heaviest part of a snowflake wheel is/may be marked near the rim with a CIRCULAR STAMP.  Put that marked spot, which is the heaviest point of the wheel balancing, next to the factory balance mark on your tire, if there is one.  For SPOKED WIRE WHEELS, the tire mark goes next to the rim valve hole.

Airheads CAN use the spark-plug hole type of air compressor, but this is a very slow fill, and may not work for getting the bead to seat.  That type of compressor is for field use. Any possible influx of gas mixture from the carburetor is quite minimal, as these devices use an intake port in the adapter itself.   However, since ANY gasoline vapor will rot rubber, at your earliest convenience deflate fully and re-inflate using fresh air.  Spark-plug hole type compressors will NOT provide fast enough air flow to inflate SOME brand-new tires, to the proper concentricity lines....but these types of compressors are fine to take on trips....as is one of the very inexpensive Chinese-made 12 volt compressors.

The original BMW wheel weights of the snap-in-place type are still available, as for the snowflake wheels, etc....as are the clips to hold them to the rim.   I prefer these to the glue-on/adhesive types, but the preference is not an overwhelming one.  Only certain sizes are still available.  The below information is subject to change.
 

36-31-1-235-625    5 gram

36-31-1-235-626   10 gram
36-31-1-235-627   20 gram
36-31-1-235-628   30 gram
36-31-1-240-152   15 gram
36-31-1-240-153   25 gram
 

You will have to hunt for the spoke-mounted type of weights, if you want the original genuine types. Here is what is available from Buchanan's: http://www.buchananspokes.com/categories/miscellaneous_tools.asp

 

36-11-2-227-943 are 5 and 10 gram segments on a strip, peel-off, self stick.  These were originally for R1200C
The clip is 36-31-1-235-632

            

NEVER EVER work on a wheel...especially with tire irons, with the brake disc lying on the ground.  Support the wheel (tire actually) on 2 x 4's, or use a lidless old oil or grease drum, etc.   Repeating a prior caution here, NEVER hang the disc brake calipers by their rubber hoses, you can seriously damage the internal plastic tubing, which has thin walls and is easily damaged.  This has been the cause for many a brake pad dragging problem....& can cause serious overheating and even total loss of your brakes.

Brand-new tires need to be cleaned as mentioned earlier herein, & need to be run ~50 miles to break them in.  Do NOT try tight pushy turns and anything but modest speeds until the tires ARE broken-in. Ride with increasingly larger angles.  However, if properly washed; and, roughed up with a stiff brush...they are more likely to be more immediately usable.  No matter how you try to speed up the breaking-in process, the tire will need some riding to warm up the tread and properly scrub-in and treat the rubber from the heat generated at the surface contact.  Tire break-in is MORE than just scrubbing off mould-release chemicals.  It can be very dangerous to not wash the tire lubricant off before riding.  This is particularly so if you happen to ride through some water....the tire can get very slippery, suddenly, and more than you might think.
 

Failure to have a valve CAP on the valve stem CAN cause you to loose air at VERY high speeds, as centripetal force allows the center part to release air (the spring might not be strong enough to prevent that).   There ARE high speed Schrader valves available.

 


Tire Tools, etc.:
 

71-11-1-237-855    SHORT tire iron, was replaced by -871 which is the longer one.   I prefer my on-bike tool kit to have TWO short, ONE long.  I have been told that BMW discontinued the short irons.   In that instance, I'd purchase & carry THREE long ones.   There are aftermarket tire irons available that are quite good.  BestRestProducts has a kit that contains irons, etc. http://www.bestrestproducts.com/

Tire repair kit:   Type depends on whether or not you have tubes in your tires.  While you WILL want to carry a tire repair kit, I recommend against CO2  bottles (ANY size).  Seldom enough of them with you, and they are EXPENSIVE in actual use.  You probably will find them to be a PIA in actual use, and it is easy to not have enough of them along, or have to re-inflate, etc.   They typically come in 16 & 45 gram sizes. You will need several, no matter the size.  FAR better is a very small 12 volt compressor, see below.  Important is something to de-bead the tire.  I have made tools for this from C-clamps with welded curved pieces on the anvils.  Probably better are commercial types that are cleverly designed, others are metal & massive.  One that folds up and comes apart, and stores nicely, and does more than just bead breaking, in fact it INCLUDES the tire irons, ETC., is this one, & you may well want to look into it:   http://www.bestrestproducts.com/c-98-beadbrakr-tcm.aspx

Just what you get is up to you.  There are some complete kits from various manufacturers, some include tire irons, patches/plugs, glue, a cylinder (via spark plug hole) operated air compressor, & they work fine.  You can purchase, very cheaply, under $20, a very small 12 volt electric compressor; remove the innards including the fan, make a plug for it to fit your auxiliary jack....or alligator clips to go directly to the battery.   BOTH of these types of compressors...spark plug hole...or electric... are FAR better to have than the near-worthless BMW hand pump that fit on the rear frame.   The electric compressors are also available for nearly $80, mounted in a modest sized can/box. I think them a large waste of money; but YOU MIGHT NOT, and the BestRestProducts.com is a good one. You can purchase the small low-cost compressors at such as WalMart.  If you want to, you can then remove and toss the case.   WalMart also likely has really small-cased versions that need no modifications except the correct BMW accessory plug (if you want that).  Coleman also sells a small compressor that does not need the case removed.   For some other ideas on tire repairs....see:  http://www.stopngo.com  and http://www.bestrestproducts.com

StopnGo plugs don't work exceptionally well with steel corded tires, but if you ream the hole really well on those tires, you can use them, but be prepared to replace a plug on steel corded tires if on a long trip.

Be sure that if you use the cylinder spark plug hole style of compressor, the compressor hose is long enough to reach each wheel; and, if using an electric compressor, be sure the electrical connection and hose is long enough. 

Many BMW airhead motorcycle riders have never repaired a flat tire, nor have they ever changed a tire.  Many have never seriously considered the consequences of having a flat while on the road; especially if out of cell-phone coverage. However...many do their own tire repairs, tire changes, balancing, and wheel bearing service.  A LOT of $$ can be saved by doing your own servicing.   Knowing it was done correctly is a big added plus.

In the middle area of the photo below is my own modified C-clamp tire bead-breaker, note the welded-on shaped plates on the jaws/anvils.   The welded-on plates are shaped on one edge of each to match the circular portion of the wheel rim, so as to have good wide contact with the tire bead at the rim area.  This particular C-clamp has been lightened a bit by drilling holes in it.   This type of modified C-clamp could be taken along with you on your rides.  Those with TUBELESS tires NOT containing tubes normally do NOT take any type of bead-breaker on rides....but you may want to take along some sort of strap or rope that fits around the circumference of the tire, in case of bead seating problems during trying to re-inflate, if the bead became unseated.  THAT usually does NOT happen.

 

 

 

 

 

 

 

The lower right area has a weighty and heavy duty tire bead breaker. You'd likely NOT take this one on the bike due to its weight, which is MUCH higher than it looks... but it is OK for the home shop that does occasional tire work.  I vastly prefer, for my home shop work, a floor type bead breaker.  For serious work, such as repairing a tube, or installing an INternal patch/plug, breaking the bead is necessary, and OFTEN NOT FUN AT ALL.  For field work you must have the tire totally deflated.   You can try the weight on one side of the center-stand; or side-stand; I think those things are iffy for most, and I prefer a tire bead breaker. You CAN carry a multi-piece bead-breaker, that assembles easily, and usable by the side of the road. I suggest the following product, and it is a LOT better than the modified C-clamp that I used to carry, all-things-considered: http://www.bestrestproducts.com/c-98-beadbrakr-tcm.aspx

In the above photo, just in front of the C-clamp bead-breaker is a modified wrench to operate the nut of the C-clamp bead-breaker, although any common open-end wrench would do.   There are many versions of bead-breakers for motorcyclists; the one shown here is very heavy.   There are some plastic types that are much lighter, and rather clever.     There is another type of bead-breaker, for home/shop use, it is shown in a photo somewhat down this article. It is what I personally use, and I have modified mine to work with motorcycle tires/wheels.

Some folks use one side of the center-stand to break the bead area, but I have never liked that method.  If it works for YOU, then you need NO tire bead breaker.  Please keep in mind that putting pressure on a brake disc and disc carrier is a VERY BAD thing to do, you could, and are LIKELY-TO, warp the disc carrier permanently.   If you plan to use the side-stand or center-stand, keep that in mind; perhaps carry a piece of wood to keep the disc off the ground.  Bending a disc carrier will cost you  $$$$.

Fix-A-Flat (or similar brand of goo like Slime) is NOT overly practical, and perhaps should NOT NORMALLY be used.  These sometimes work on tube tires, but may work better on tubeLESS tires.  Fix-A-Flat and similar makes a mess inside the tube/tire/wheel, OFTEN does NOT work (particularly tubed tires), often prevents a patch from sticking if you are forced to try that later.....and if the stuff does work, it often fails shortly thereafter.   One should NEVER let a dealership repair your tire later-on without first telling them that you installed that stuff. You will NOT like using solvents and rags to clean out your wheel if YOU are doing a tire job.  Most dealerships will NOT be happy finding out that your tire/tube/wheel has that messy stuff in it. Cleaning it out takes time. Time is money, ...out of YOUR pocket.    SOME do carry these cans of pressurized goo for emergencies, and have had decent results.  It DOES give added protection if you are doing a tubeless repair, particularly with steel-belted tires, or any tire with steel cords. 

At the lower front in the above photo is a common patch kit for a TUBE-type tire.  The patch kit contains patches AND A SMALL TUBE OF GLUE.  BE SURE you check your glue tube now and then....even if has never been punctured for use, they have been known to dry out.  Some folks replace those glue tubes yearly.  Others, LIKE ME, purchase a larger container, usually a small metal can with a brush inside the screw top, and check it every year. I even go so far as to add a bit of the proper solvent every time I open the can to check on the stuff.

I have not shown a kit for tube-LESS tires....see information later in this article.   

At the top middle area of the above photo is a package containing a new spare inner-tube.  For most bikes with not hugely different front-rear sized tires you can use a front or rear tube at front or rear in an emergency.   It is usually OK on our BMW's to carry just a spare rear tube, rather than a front tube or both.   Also in this photo is an old pill bottle that contains real tire talc (REAL tire talc contains no oils that rot tubes); needed for tube type repairs.  To its right is a plastic squeeze bottle with flip lid; one can use any sort of these flip lid plastic bottles, such as from hair styling products, and this particular bottle is partially filled with REAL tire lubricant liquid, made from properly water-thinned concentrate. Some use thinned soap, I vastly prefer REAL tire lubricant, which actually is 'flaxsoap', which is not a soap as you would normally think of soap.    Auto-parts stores carry real tire lubricant in tubs (thin per the tub-printed information) ...one tub will last several lifetimes for you and several friends; so share your 5 pound tub with your buddies.   

Note the electric air pump with hose & electrical cord (I removed and tossed the original large plastic case before taking this photo).  These are available very cheaply, often less than $20, from such as Wal-Mart, etc.  The large outer plastic case is removed, and the small fan removed by cutting the shaft with a Dremel or similar tool, & alligator clips as shown or perhaps a BMW accessory plug attached at the other end.  The current drain from the battery is fairly low for this item.  Some of these pumps have air pressure gauges which can be utilized, or not.    Motorcycle batteries ARE capable of running these small electric compressors to fill quite a few tires....and still start the engine. These cheap little Chinese compressors also hold up better than you may think.  Some folks are packaging these tiny piston compressors in their own metal box, and selling the boxed compressor for $$$.These electric pumps are now available in a SMALL package; previously they were not....so see further down this article for photos of them. 

The engine-driven type of pump is at the lower left in the above photo;...these come in kits with various sizes of spark plug hole adapters.  Only the 14 mm spark plug adapter is shown in the photo.  NOTICE above it are two coiled-up Sash Rod springs, available from any hardware store.  Those two springs, when you need to use them, are wrapped around the engine cylinder and spark plug metal body, so that the removed spark plug, with its electrical cap attached! can be held to the cylinder fins, to avoid injuring the ignition system during the one-cylinder operation of the Airhead engine.  If the spark plug was just laid on the engine, it could fall off, and produce an open circuit, causing a lot of $ damage to the coil(s), that might not show-up immediately.  On the 1981+ models you can additionally damage the Hall device in the ignition canister, and even the ignition module under the fuel tank.  Damage may not show up right away!

This next photo is another type of bead-breaker....very practical for the home or small shop user; can easily be modified to work well with motorcycle-size wheels by removing the small vertical tab. You may want to extend its tail a bit too.  Using it with two pieces of 2 x 4 allows it to be used with single or dual disc brake wheels, without putting pressure onto the discs.   The bead-breaker shown here in its automobile usage style, not yet modified;....is not expensive, often available from such as JC Whitney; or other stores.  There are motorcycle specific versions of these, most are fine. 

 

 

 

 

 

 

 

 

***There is a bead-breaker combined with tire irons, a clever, if complicated looking unit, that is called the TireIron BeadBrakR, sold by  www.bestrestproducts.comI have not tried this unit myself, but have heard favorable reports from those that have purchased and used this item.  It completely folds-up and is a small package, totally carry-able on your bike.

Frankly, I do almost all of my tire changes, and there have been MANY hundreds (really!) with three old-fashioned tire spoons....the heat of the sun, talc, proper compressor setup, tire lube, etc.

The two compressors, below photos, are small; but, if you want even smaller, you can get one or some other type/style of these Chinese-made compressors, and discard the case and gauge. I did that for the compressor that is a much earlier photo (with all the various miscl. tools) in this article, well above.

A small compressor, basically a plastic-cased version of the one in the first photo at the top of this page.  This one, in its blue package (the carton it came in is in the photo), came with a standard American cigarette lighter plug, which I changed to alligator clips.  $9.99 at Wal-Mart Slime brand compressor. Small, fits easily with tire tools in my Airhead's fairing pocket. Fits tool trays too, leaving some room.  $9.99, Wal-Mart, June 2015.  I installed a DIN style plug; standard for BMW motorcycle use, instead of the cigarette lighter plug; it plugs into any BMW bike accessory socket!

 

I do NOT recommend CO2 cartridges for repairs.  Best is a cylinder pump or an electric pump as shown in the above photos. It can take way too many of the small CO2 cartridges to fill a tire adequately, typically even a handful will only fill the tire partially.  Even the larger CO2 cartridges are not adequate many times. Also, if you have to refill the tire if the repair worked only partially in such as seating the bead, you'll likely have no more cartridges.  More on cartridges a few paragraphs below!

For TUBELESS TIRES (no tubes inside) repairs when on the road, you should carry on the bike some sort of tire plugging devices and tools for them.  One common brand is Stop&Go, either the standard model 1075 gun type, or the compact hand unit model 1000. NOTE that the Stop & Go tire plugs are also useable for steel belted tires, but with steel belted tires the injury hole MUST be reamed really well, with the tool included, before installing the plug.  Failure to do that will likely result in the plug being sheared and permitting a leak very soon.   In general, I recommend the StopnGo smaller plugger kit, and ALSO recommend you carry BOTH their plugs PLUS some sticky-strings ...and glue/cement.  In quite egregious instances, having a plugger kit, sticky strings, and extra cement, can be very worthwhile.

There is something hardly ever said, that is favorable for some tires (and, any others similarly constructed):   A tire that does NOT use steel strands in the tread is much more likely to have a LASTING repair, from use of sticky strings or internal patch.  This is particularly so if you are using such as the Stop'nGo mushroom type of plugs, which require extra reaming on steel belted & steel ply tires.  The Avon Roadriders do NOT have steel plies, and there are many others.  Conversely, that makes them POSSIBLY more conducive to punctures.  Strictly speculations!
 

I personally have had one exceptionally bad large tire puncture, not a round hole either. I had to use BOTH sticky strings & mushroom plugs.  When this nasty bit of metal went into the tire, it did not go straight in, but went in on an angle before it straightened out. I then had a rectangular, large, & truly nasty hole in the tire.  Was the devil to get the tire to hold air so we could get home.  We were maybe 70 miles away, in the mountains.   Towing service asked for $800: NO WAY!    I managed to fix the tire enough with sticky tire repair inserts & two mushroom inserts. I carry a tiny electric pump which did fine (see photo of all the tools, WAY above).  It had to be used to inflate the tire 3 times from flat, + topped off once, & this is not a motorcycle tire, but a car tire on my sidecar rig rear wheel.  I replaced the tire when I got home.


Plugs, installed from the outside, are a temporary repair for tubeless tires.  You are not supposed to travel far and fast using an externally plugged tubeless tire.  Many have done it, but I do not think it advisable and I DO NOT advise doing it.  Many who have bikes with tubeless tires will carry a tube, for emergency repairs, not trusting external plugs.   Many have temporarily repaired tubeless tires with a 'string' or other type of external plug.  Many have gotten away with this for the life of the tire.  My suggestion is that you do NOT do this, but have your road-side temporary plug repair properly fixed at the next available dealership.....or, do it at home. So, what I am saying is that tubeless tires should eventually be properly repaired with an inside patch-plug....or replaced.    Please keep in mind that if you install a tube in a tubeless tire, you should reduce the tire speed rating by one step, as the combination causes more heat to be developed.
 


WHY I do not recommend CO2 cartridges (of ANY size); & some hints when NOT using cartridges:

I do not use CO2 cartridges.  Besides their cost & bulk, they will not really do the job much of the time.  I prefer the tiny electric compressors shown above, even though they have lower instantaneous air available.  CO2 cartridges ARE  "somewhat" adequate to inflate a TUBED tire after a flat repair or a new tube is installed on the road someplace.  It takes WAY too many of of them to actually inflate to the proper pressure....a nasty little drawback, hardly ever mentioned.  They are adequate for tubeless tires, BUT ONLY IF THE TUBELESS TIRE IS INTACT AND ALREADY SEALED TO THE RIM, ALL AROUND.  They STILL will NOT inflate the tire more than enough to travel at low speeds to a place you can do a proper inflation.   If the tire is not properly inflated, it WILL get hot, perhaps TOO HOT.   Steel-belted tires will have more flexure at the plug repair; the steel sharp points will possibly shear it off.
 
It is NOT unusual for a tire to move to inside the rim when it goes flat.  This can be a little, or a lot of movement.   This can even occur even with so-called Safety Rims, which have bumps or ridges to help prevent the tire from moving into the center well.   When that happens, or even if it does not, to a tubeless tire, not containing a tube, you MUST find a way to bring the tire sidewall fully in contact with the side of the rim, in order to inflate the tire.  One has a lot of leeway on this in a SHOP situation, because in a shop you have the ability to remove the valve CORE, and use a tire chuck, or modified tire chuck, on your compressor with the tire chuck center removed, and you have strap tools.    That type of modified tire chuck, and a tank of high pressure air driving it, gives a LARGE flow of air, just what is needed in marginal situations for trying to seat the tire sidewall to the rim.   That is NOT available in the field. CO2 cartridges do NOT have proper inrush VOLUME SPEED, NOR actual total VOLUME.  

   
For those with tubeless tires, NOT running tubes, I recommend your favorite plugs, patches or string or whatever style of repair kit you wish to use (with reasonably fresh rubber cement!).   I DO recommend you carry BOTH sticky-strings and some sort of mushroom plugs, and have a piece of rope or long strap that goes around the outside circumference of the tire, which you can use with one of your tool-kit items, like a tourniquet, in case your tire no longer is sealed to the rim.  I also suggest tire lubricant (the REAL stuff).
 
Tire plugs of the Stop-'n''go type are useful, but if you have steel belted tires, be SURE to ream the tires quite well & be prepared to re-plug & use sticky strings if needed, & re-inflate, if the plug fails.


Hints, methods, advice, ideas to consider, ETC:

If your fuel tank is approximately half full (or more), I "suggest" you REMOVE the fuel tank before repairs, IF...IF...you have to lean the bike over on the ground.

One very popular method of repairing the rear tire on ALL twin-shock airheads (some do it for Mono and Paralever bikes too) is put the bike on the center-stand and then to SECURELY! tie the center stand to the front exhaust crossover pipe.   Remove the front wheel, don't hang disc brake calipers by their hoses!!    Tilt the bike forward onto the fork lowers, onto something like your gloves, etc., to protect the fork bottoms.  Be sure to bungee any disc brake calipers so their hoses DO NOT have sharp bends, especially at the fittings ends. NEVER hang disc brake calipers by the hoses!   

This crossover-pipe method is what I personally do.  I HAVE, in the boonies, simply removed the fuel tank, and laid the bike over on whatever the surface is.

Below is another method of strapping the center-stand ...here it is to the front forks.  Note that the owner is not using any strapping of any front exhaust crossover pipe to the center-stand.  Photos courtesy of Dann Rudd (which I cropped).  You really want to be sure that the strapping can NOT come off suddenly.  YOU MUST, if doing it this way, do it such that the bike CAN NOT POSSIBLY fold-up the center-stand rearwards during the lashing operation!

In the photos below, Dann has the strap around the very bottom below the axle fitment projections of the fork lowers.  Be very careful that the strap can NOT come off the lowers.  The bike is being tilted forward so that easy removal of the rear wheel can be made for whatever servicing needs.

In general, you will have only REAR tire flats.  In a field situation, you remove the front wheel, re-insert the axle, and tie the axle or forward exhaust crossover pipe VERY SECURELY to the center stand.  I tilt the front of the bike down onto the ground.  On the ground I placed one of my gloves under the left fork lower, and one of my gloves to be under the right fork lower; but you don't have to.


      


NOTE!!!.....Snowbum does NOT use the above strapping method; he uses heavy-duty Trucker's type bungees, between the front exhaust pipe crossover and the center-stand.   He has NO problem with you using the above method; using quite long straps, etc., to the center-stand, in any SECURE fashion.  NO MATTER WHAT METHOD YOU USE, YOU REALLY REALLY DO NOT WANT THAT CENTER-STAND COLLAPSING BACKWARDS!!!!!!

The best on-road fix is to discard the old tube & install a new one with tire talc put on by your hands.  It is also MUCH faster than removing, patching, & reinstalling the original tube. Purchase another brand-new tube for your on-bike repair kit items soon.  Don't forget to remove the offending nail, screw, etc., from the tire...many have forgotten to do so!! Unless your front and rear tires are the same size, or close to the same size, it is really best to have both sizes of tubes. Many do not, and carry just a rear, which can be put into a front in many instances (such as 18 rear into 19 front, but not recommended for 18 rear, 21 front).

The next best choice is to repair the tube & continue on.

Some do not carry tire repair items, or have limited items, or install some sort of sealant product into their tires or tubes.  YOU REALLY SHOULD HAVE DECIDED, LONG BEFORE any ride, what YOU are going to do about flats.

NO TUBE that has extremely long splits, tears, etc., should be patched, and usually the patch is not successful if huge, on a motorcycle-sized (or bicycle-sized) tube. 

Butyl AND natural rubber tubes, with punctures or small tears/slits, etc., are certainly patchable, contrary to some beliefs.

Most people fail to first roughen the tube and clean it properly. Most also slather on WAY too much tube glue (DO check now & then that YOUR glue is in good condition!).  They also fail to dry the applications of glue the correct amount of time. They additionally fail to allow a long-enough final cure.  All these things can lead to patching failures.
 


There is a lot of misunderstanding about tubes, tubeless tires, tube-type tires, types of tubes, etc.  This is slightly edited from a posting I did to the Airheads LIST, on 04/05/2015.   A lot of information follows this section.

"The insides of tires vary between manufacturer's, including differences between models of their tires. This particular variance I will describe happens on both tube rated tires & tubeless rated tires (which can be used with tubes). The inside of the tire may...or may not... have MANY RIDGES, that you can see, and feel. These ridges are on an angle (NERDY TYPES might concern themselves with those angles and tire rotation direction, if not marked, most of the time the tire IS marked for one of several reasons) and provide places for the TUBES to press-against, and thereby the tubes deform a bit to the ridges during inflation, and so are more or less captured in a more or less fixed position. The tubes are then less likely to rotate inside the tire upon a flat being experienced. Some feel that the tube SHOULD be allowed to rotate slightly.   A bit of allowance, in case movement does happen (more likely on NON-ridged insides of tires) is had by following BMW & other's advice, & NOT screwing the installation nut down to the rim, but, discarding it, ...or moving it up to the valve cap. THAT IS proper & allows the tube to move a bit, before forces would tear-out the entire valve stem, making not only for an UNrepairable tube, but allowing, typically, a very fast air release. NOTE that the 'plastic tubes' are
more likely to have this type of damage. I HIGHLY RECOMMEND THAT YOU USE A LOT of REAL TIRE TALC ON TUBES & INSIDE OF THE TIRE, WHEN ASSEMBLING THE TUBE & TIRE.  YOU ARE LESS LIKELY TO GET A TUBE FAILURE FROM FRICTION EFFECTS.
 
Plastic versus rubber (or natural rubber) tubes:  The prime difference in materials is the percentage of the two types in any given tube. There are NO 100% natural rubber tubes; nor, AFAIK, no 100% plastic tubes.  I could be wrong on that last point.

In order for the tubes to properly equalize to the tire inside, & that includes the movement during normal tire rotation as you ride; & to ease installation, tire talc is generously applied to the inside of the tire, and onto the tube surface too, by one's hands...rubbing it into the materials....during tube installation...including when installing a new tire.  This is also why after first inflation using tubes, you are supposed to totally deflate, and bounce the tire around at various points, to help equalize, distribute tube folds (if any), and then re-inflate.  Any tube fold  left because you did not do this WILL result in stresses.

If you remove a tube for patching, & reinstall the tube, it is HIGHLY UNLIKELY to align itself with those tire ridges again. Under the best of circumstances, the alignment is not perfect. If the tube sides are reversed, they will NOT align, EVER. The bottom line here is that the tube has stretched & thinned in narrow but longish areas, where these ridges made tube changes. Thus, the tube is weaker at those areas. Tire & tube makers always say to replace the tube, rather than repair it....or, they say to always replace the tube with every tire change.  Obviously, the implication, and sometimes this is stated, is that a reused tube, patched OR NOT, is less strong. Thus, a patched tube should be regarded as a temporary on-road emergency fix. I completely agree. I am WELL-AWARE that most of you reading this probably will continue to use that tube.  We all know few pay any attention to these things. Some, usually very few, have gotten bitten.

Guess what type of tube material is less conducive to blowouts or serious air releases upon a puncture (or, break at a ridge line mark)...?  yes, 'natural rubber' tubes...

 


Yes, after all the above ...The main section begins here!!

When you start working with an existing tire on the wheel, deflate it by REMOVING the Schrader valve core; if the tire is not flat, do this slowly, as the valve core may tend to shoot out suddenly, and head for the unknown.  "Break" the tire bead on BOTH SIDES of the wheel, being careful of any brake disc.   PUSH the valve stem (on tubes) to the inside.  REMOVE the tube.  Remove the tire, unless just repairing a tube....if so, be SURE you have removed the puncturing item BEFORE removing the tube.  When you replace a tire, inflate the tube a small amount, just to shape it a bit & install into the tire.  Put the wheel rim on an angle, & insert the tube's valve into the rim hole. Feeding the tube stem into the rim hole can be difficult.  There is a tool for that that makes it easier.  Later in this article I will have some specific advice and photo of the tool.   Once the stem is inserted through the rim, put on the nut a few threads. START spooning-on the tire at a point totally away from the valve...the opposite side of the rim.  Repeat on other side. It is during this spooning-on procedure that many make the mistake of doing it wrongly, and pinch the tube. Be careful, and watch what you are doing!

There is a lot of confusion about tubes & installing them:
1.  They should be installed using a fair amount of plain unscented talcum powder (sold cheaply for tire/tube repairs), pour some on your hands, and rub lightly all over the tube...and repeat for the inside of the tire.  You need NOT apply any on the tire BEAD area.

2.  Tubes come with plain stems vulcanized to the tube; and may or may not have a concave washer, and one or two nuts, and a cap.  The cap may be a metal type with a rubber internal air seal, or a plastic type, that usually seals air.  The purpose of a concave washer, if the tube comes with one, is that the construction of the tube valve area is such that the concave washer goes on the valve on the inside of the rim. If there is no concave washer, you do not need it with that particular brand & model of tube....unless it is missing!  For TUBELESS TIRES being used on MOTORCYCLE TUBE TYPE RIMS, you will see that the rim hole is 8 mm.  If you do not wish to enlarge the rim hole for a standard pull-in type of stem (often not a good idea, due to the shape of the rim and trying to get a decent air seal at the 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.

3.  If there is a single nut, that is used to help you with installing the tube into the rim hole.  That nut is put on the OUTSIDE of the rim, TEMPORARILY.  When the tube and tire are fully mounted, the stem must be at 90 to the rim. Once it is, either toss the nut, or, screw it up to the CAP.  The nut is NOT to be tightened to the rim.  The tube stem must be free to move about a bit in the rim; this   helps if the tube and rim try to rotate a slight bit to each other, it avoids the valve assembly ripping out of the tube.  The stem also acts as an indicator, and if it is not, in the future, at 90, you know the tube has rotated.

4.  If there are two nuts, the primary purpose is to allow use of the tube in a TUBELESS RIM.  That is because the valve stem hole in a tube type rim is 8 mm, and for a tubeless rim it is 11 mm.   The inside nut is usually a hex type, and the outside is usually a knurled round type.  If there is a concave washer AND this second nut, you could use both.  In this situation, however, I carefully inspect how the tube was constructed, and I may well not use the inner nut. In any case, do not screw the inner nut, if used, tightly down the stem.  NOTE that a concave washer may be better to use than an inside nut. INSPECT your tube and rim!

5.      Most everything else:
Most will install the tire on one side, then install the tube, then install the second bead.  Be very careful, no matter how you do yours, that you do NOT pinch the tube with your tools!!!  It is even possible to put a hole in the tube in the VALVE STEM area, if the tire bead is trapped and moved about at that point.   Take your time to watch what you are doing!  It is vastly better, and easier, to do all work with everything in hot sunlight, until quite warmed-up, & continue the work in such sunlight.

a.  Any puncture or tear needs to be cleaned up, sanded/abraded with a inner-tube metal abrader, & best to do that VERY thoroughly; don't use sandpaper, unless you have a way of solvent cleaning the area afterwards (gasoline if you must).    Next clean the area with alcohol or other solvent; gasoline is NOT good here, it MAY have ingredients that MIGHT prevent solid patch adhesion.  Gasoline is better than nothing.    Using one of the repair kit patches, peel off the protective layer, KEEP FINGERS OFF THE ACTIVE STICKY SIDE.  Using a CLEANED fingertip, spread the smallest amount, thinnest layer, of the cement goo on the tube, and the patch's active adhesive side.  Yes, BOTH of them.   BE SURE the patch is covered to its own edge. BE SURE the tube is properly prepared & you kept your dirty fingers off of the repair area and patch active surface.  Allow each application of the tube's goo, in tiny amounts remember!... to dry.  How long depends on humidity and temperature.  I suggest several minutes.  Repeat the fingertip application of glue THREE TIMES. Use the TINIEST amount of goo!!!  On the last application, before it is totally dry, press/clamp the tube & patch together & leave clamped for a day or so if at home. If doing this on the road, try to clamp with some sort of flat wood or ?, as flat as you can; and try to have the patch lay quite flat, particularly at its edges!  Allow as much time as your patience allows. When installing the tube, use your hands with TIRE talc all over the tube, and inside the tire. I like to wait a bit after inflating, perhaps 15 minutes or more, before riding on a patch job.   My personal method of on-road repairs, AND in my garage, is to R/R tubes with one side of the tire still inside the rim.

b.  If your tire is marked on either sidewall that it is to be installed in one direction, pay attention to that.  On BMW twin-disc wheels, the carrier NUTS are normally on the LEFT; which, thusly, identifies the wheel direction of installation. BUT.... many wheels and some discs, are marked for direction.  Whatever your wheel is, consider keeping it that way, or you will need to re-break-in your disc brake pads...however, there may be reasons to install it correctly.  

c.  Install one sidewall of the tire onto the WELL-CLEANED inside rim surface first, using tire spoons and REAL tire lubricant.  Cleaning the rim bead surface is important, do the best you can if on the road.  I've carried sandpaper for this purpose.  At the least, use gasoline and a rag (careful! flammable!!). It makes for easier bead seating.

d.  Sidecarists sometimes use rear tires at the front, and front tires at the rear.  Sidecarists may mount tires with any direction disregarding any arrows.

e.  Some motorcycle tires now come with molded sidewall information FOR BOTH DIRECTIONS.  The tire has mould marks on that tell you which direction the tire should be, for front or rear use!  Sidecarists and some 2-wheel riders also do strange things, such as using rubber pieces under the rim where the valve stem sticks through, and rubber on the outside, then have the stem nut and cup washer against that.  The idea is that the tire, whether a tubeless type or not, will hold some air, for awhile at least, if the tire/tube is punctured.  Normally, the proper installation is no rubber things, and the nut that comes with tubes is threaded UP to the TOP of the
valve stem, meeting the stem air cap.  The idea being that if a flat occurs, the tube (you DID install it with tire TALC all over it surface, and tire insides too?) can move a slight amount, with tire movement on the rim... avoiding having the tube stem rip out, making for a very sudden flat.  BMW even had a service bulletin about that.

f.  HINTS:  Feeding the tube stem into the rim hole after the tube is otherwise fully inserted into the tire may be difficult; especially if the sidewall is quite stiff.  The sidewall may need considerable finger pressure, & some may use a small block of wood or a tire spoon to keep the sidewall more open.  If you go too far with that idea, the other side of the tire will move & block the valve access.  Some have used forceps gripped onto the stem threads to help guide the valve into the rim hole.  I recommend you do NOT using any tool that can injure the threads.  There is a thin braided steel flex cable tool available, it is specifically for doing this job.  It screws 
INTO the valve stem.   Tusk Valve Stem Puller  part number 1188500001.  Get one of these; try your auto-parts store, if necessary an internet search.  These really work nice for tubes.  But, it is not the only type of these tools.  I recommend you own both types, see the two photos below, or, at least the second type modified slightly as noted.
        
              
Below is another type, this one was for tubeless rims for pulling the valve stem into place. If you modify it, it will work on tube type rims.    The Knurled end of this tool, see photo note, as purchased, will NOT fit through the smaller diameter TUBE-type rim holes; it WILL, if you carefully thin the outside diameter, by grinding the knurled cap end a bit thinner.  Grind the O.D.
just enough so it goes through the rim hole without forcing.  If you grind too far the walls will be too thin.  Haltec TL-645-24, or Grainger 33510, or similar on Ebay.   Get ONLY the flexible cable type as shown here.  One of the dual-barrel ends of this tool is to R/R the valve core, and the other end is to depress the center pin of the valve core on an already inflated tire, and there is a small side hole; this allows the air to come out slowly, avoiding you unscrewing the valve core and have it, from air pressure, flying into 'never-find-land'.  
        

Once the tube valve stem is in the hole, using one of these two tools, then put the nut on the stem, only a few threads!

g.  You also want to line up the painted dot or other painted marking, if you have such on the tire, with the valve, when installing the tire onto the rim (I do it before installing the tube, if there is one), before spooning the second sidewall onto the rim....this is a good time for more tire lube...note that tire lube is used on the bead seating area of rim/tire...and, on the EDGE of the tire bead area.

If you have to, move the OUTSIDE nut down fully to the rim, & move the tire slightly one way or the other (NEITHER bead has snapped to the rim yet, because you have NOT inflated the tube/tire) so the stem is centered and at 90, in the rim hole.   The valve stem should be at 90 degrees to the rim, and, the tire marking(s) lined-up, BEFORE spooning the final bead or inflating.  Do the spooning of the final bead now.

Assuming you now have the tire and rim and tube valve in proper alignment, move the nut upwards a number of turns.  It is best NOT to have the nut down to the rim and tightened just before inflation. The purpose of the outside nut is ONLY to keep the valve from going back inside the rim during your work.  This outside nut that is used as a tool can be tossed after installation, or, moved up to the stem cap. I recommend you move it up to the stem cap (after cap is tight), as sometimes new tubes do not come with a nut and I like to have one, in case I do not have the fishing tool, and, it makes things easier even with the tool. DO NOT leave this outer nut tightened to the rim on a tire containing a tube!  Even BMW had a bulletin on that!   The stem should be free to move about in the rim hole, stick straight out at 90, and not on an angle, when you have the tire/tube/wheel properly assembled and inflated.  You cannot determine if there is any side forces on the tube, unless you have the nut loose, during and  after inflation.  When done, THEN you can put the nut against the cap. DO NOT fail to use a cap that SEALS well.  Obviously if you have a tubeless tire, used as tubeless, you have NO inner-tube, and you have NO inner-tube type of valve stem to worry about.


h.   On a rare occasion a tire will not balance properly without a large amount of tire weights added.  It is OK to have the tire painted mark at 45 or even 90 degrees to the stem, if doing so reduces the amount of weights needed.  VERY FEW motorcyclists do this, as they hate bead breaking after mounting a tire, and you must be careful with a tube.

i.   Many modern motorcycle tires have VERY stiff sidewalls and beads and can be difficult to mount to your rim. In particular you may have difficulty getting the tire bead to seat all around, concentrically, on both sides of the wheel.  Copious quantities of tire lubricant will often help. Often the tire beads snap into place over a few minutes.  A big help is to have the tire, wheel, tube, etc., all in the hot sun for quite some time, before and during ANY tire work.  Use of too high pressures to get the tire to seat properly are dangerous.  Not all that rarely there are problems and even with repeated inflation, deflation, inflation, a clean and polished rim bead area and well-lubricated bead, the tire may not seat all-around.  This usually happens on just one side of the wheel and on a smallish part of the circumference of that particular bead.  While it is true that....in VERY rare instances, a tire is faultily made...or a rim unequal on each side (usually due to straightening of the rim at some time), those are VERY rare instances.

To avoid problems, I recommend that you follow ALL my suggestions FIRST, ahead of time...as best you can with your equipment.

ALWAYS CLEAN the rim inside bead area wall, so it is clean & very SMOOTH...this allows the tire bead to slide on the bead area easier during inflation.  The tire bead rubber will always try to grab onto the rim bead area, so a clean and smooth bead area, including the edge of the rim metal is important.  Use WATER and SOAP FIRST to remove old water-soluble tire lubricant, which acts something like glue when it is dry!  Then use a strong hydrocarbon-based liquid solvents, perhaps acetone or MEK.  Finish cleaning with fine sandpaper, then clean off any sand from the sandpaper, then WASH with soap & water again.  I cannot over-emphasize the need for a truly clean & smooth rim where the tire bead will pass over and then seat.   This is VERY helpful for both tube & tubeless tires in both spooning-on, AND in having the tire set fully concentrically to the rim.    Doing it properly will reduce your swearing & labor CONSIDERABLY.  A rather minor-appearing irregularity on the rim bead surface will be a point of substantial friction, which you do NOT want, once the tire bead is in contact with it during inflation.

Do NOT leave the Schrader valve core inside the valve stem when trying to seat the beads.  That valve, together with perhaps your air source being of too low a pressure, or too small a tank or no tank, too restrictive a hose (or chuck!!)....may not allow a fast-enough inflation.  

The PRIMARY SECRETS ARE:  VERY clean and smooth rim/bead, proper lubricanat, & FAST inflation using high pressure tank supply.   Otherwise, the lubricated bead STARTS to move, & then hangs-up.   Many have very considerably overinflated a tire (to quite dangerous pressures) & still could not get the bead to seat.

For tires withOUT tubes, there is another possible problem, & that is to get the tire to even start to seal to the rim, let alone fully seat/seal.   This is ESPECIALLY a problem if you have a very low output compressor (12 volt, on the road??) or limited CO2 bottles.  The answer is almost always a big belt or rope used as a tourniquet, around the entire circumference of the tire. Use a large tool of some sort, even a piece of wood, to tighten the tourniquet.  

Heed my hints!  I cannot overemphasize the need to do all of what is in this section!   HAVE THE TIRE & WHEEL HOT!   Remove the valve core & use a compressor hose, & associated parts including fittings & airchuck, that flow fast in volume. DO USE a modified airchuck that will fill the tire FAST (with well-lubricated tire bead too, on very well cleaned and smoothed rim).  A several gallon size (OR MORE) TANK at the compressor, high pressure (at least 80 psi, but 125+ is nicer) is very helpful to supply the huge amount of air FLOW really needed.  Check that the air HOSE is of the 3/8" inside diameter  MARKED type, NOT smaller; or flow will be slow (low flow volume is is BAD).  Do NOT purchase an air hose that has too small of a hole inside at either end fitting.  The hose length is NOT very critical, but the shorter the hose the better.  The entire air supply system needs substantial INside diameter parts.

I have found that SOME quick-release hose fittings are quite restrictive.  It is best to avoid them. Modifying quick release fittings is iffy...best to avoid doing that....but I HAVE modified mine using progressively larger drill bits (or reaming).  It takes very little diameter increase give a HUGE increase in air flow.

OBTAIN AND MODIFY AN AIRCHUCK specifically for this tire work:   REMOVE the center pin.  LEAVE the rubber washer in the chuck (after you modify the chuck).  DRILL the part of the airchuck that attaches to the air hose, for a larger size hole...all the ones I have seen are too small in diameter.  15/64" or 1/4" will be OK.

USE REAL TIRE LUBRICANT, properly thinned.  USE A 2" wide cheap paintbrush to apply it quickly so both rim (and outer edge!) & tire bead are well-coated.  If it starts to dry, re-apply or use a water spray from a cheap plastic bottle sprayer.

j.  I can't tell you a specific maximum pressure to try to seat tire beads; frankly I do not know what is truly safe for your particular wheel...let alone any particular tire. Motorcycle tire manufacturer's use to say not to exceed the maximum sidewall printed pressure by more than 50%.  Some said 150% ...which they meant to be 50% over the maximum sidewall printed figure, but that 150% could be miss-interpreted as sidewall printed maximum pressure PLUS 150%.  THAT would be EXTREMELY SUPER DANGEROUS. Recently, perhaps lawyers got involved with the litigious American's, as many tire makers are saying not to use higher than 40 psi when inflating. Some of these same manufacturer's have deleted their prior higher recommended pressures for RIDING too! This all may fly in the face of ~ 42 psi being a maximum on many sidewalls. I like the old recommendations myself...... & to restate them:  DO NOT use over 1.5 times the printed sidewall maximum. Speaking as my lawyer might advise me (besides not to say ANYthing), I am NOT advising you DO use 1.5 times.  My information here is of how I PERSONALLY DO MY OWN WORK.  
I would NOT want to inflate a tire so high that a rim exploded, let alone the tire be injured (they ARE injured by high pressures).   There is always the chance that a rim has been weakened, making things even worse!  I never ever go over 65 psi on common motorcycle wheels. 

I use a compressor that fills its tank to 125 psi (my compressor maximum safety pressure as printed on it), & I use all my previously noted hints about hose size, air-chuck modifications, no Schrader valve core, etc.  I usually use a gauge in the hose fitments, to tell me the PSI that the tire is being filled to. 

Please keep in mind that while a pressure change from, say, 50 to 60 psi seems hardly much, the pressure is POUNDS PER SQUARE INCH...and there is a lot of inside AREA for those pounds.  Thus, the pressure on the wheel can be MANY THOUSANDS OF POUNDS; and an increase of just 5 psi is a LOT, considering the total inside surface area.

I use REAL tire lubricant with a paintbrush.  Tire lubricant comes concentrated & looks like very thick jelly.  I thin it with water per the can.  If it dries out, add water from a hand-sprayer, or more tire lubricant.  DO NOT use lubricants that contain oils.  I am well-aware that some of you will use saddle-soap, dish detergent, soap, etc.  You have MY recommendations.

Once the WELL-LUBRICATED beads snap into place on both sides of the tire, & not exceeding what I believe to be a safe pressure, I check the RIDGE that is molded on the tire near the bead, to be sure it is EQUAL all around, on BOTH sides of the tire, that is, concentrically, all-around.   IF NOT, I first WAIT a few minutes...as sometimes it takes a bit of time...and, again, here is where lubricant and hot tire and hot wheel from being in the sun really does help.  Not seated correctly?....I deflate, break the bead, lubricate, repeat the process.  I may have to increase the pressure, but never over 65 psi for common BMW rims.   If you do this procedure the way I have outlined,
you will almost always have good results THE FIRST TIME, AND NOT HAVE TO DEFLATE & TRY AGAIN.
 


Vibration/Thrumming/etc.

A tire from any one given manufacturer is usually intended to be used with some other tire from the same manufacturer. In a fairly large majority of instances, tires can be mixed by model & manufacturer with no or few problems. In some instances they do not work well with each other.  Every tire has its own type of vibrations set up by/in the tire & transmitted to the suspension, frame & you.  In fact, suspension operation can also transmit vibration to the tire, synergistically. Even if the tires are perfect, & balance of wheel & tire is perfect, vibrations still occur, & if the front & rear tire were not designed to work with each other, strange effects can come about.  Vibrations come from from the tread design and how it pressures air as it rolls down the road, plus rhythmic things that come from tire tread squirming, ETC!   In many ways, the suspension system and even frame rigidity, and other such factors, influence tire vibrations.

Such effects in one tire creates something almost like a musical beat note with the other tire's noises....OR, what is created is a rhythmic vibration and/or noise, something like a regular interval thrumming that rises & falls in amplitude as speed decreases & increases, from any one speed.

In some instances, even proper mating tires can do this, depending on wear patterns, & a LOT of other things.  Some of these things, and/or causes, are not well-known or thought about. On Airheads, insufficiently tight motor mounts, for instance. Shock absorbers can have a dead place that is exceptionally narrow in stroke amount, & can cause vibration. If you change the loading on the bike, thrumming may mysteriously appear or disappear.  Balancing tires & wheels might only help somewhat, if at all....since often balancing is NOT the basic problem.  Just about anything that changes the characteristics of the bike in some way, will allow new or different vibration modes.

Other items that are often at fault are twisted forks, forks with stiction, looseness almost anyplace, & sometimes 'things' added to the bike that change vibration modes from the stock situation.  A flattened center-section of the REAR tire from normal wear can cause thrumming, noises, and be VERY dangerous at speed, as it promotes high speed INstability, even of the type known as a Tank-Slapper.

In some instances vibration and thrumming began after the front tire was worn, this happened now & then with the Metzeler Laser, which is very compatible, due to tread design, with almost any rear tire. The Metzeler Laser is hardly the only tire to have these problems now and then.

Braking/sliding that causes a worn place over one area of the tread, and not another, is a VERY prime cause. This often comes about from either very strong braking & sliding on an abrasive surface, that flattens, ever so slightly, part of the tire. The type of thrumming this causes can be exceptionally pronounced.

My point is that before blaming tires & balancing, DO check your nuts & bolts, & feel the front end for the steering head tightness or looseness & rear suspension. Check wheel bearings for looseness.  Check the rear wheel fasteners; particularly on the single-sided models....they do have a torque setting, & those threads are
never to be lubricated, & that includes not ever using antiseize compound on them.  If you cannot find the problem, remove the rear shock absorber(s), remove the springs from them, & test them over VERY SHORT movement conditions, in the SAME vertical/horizontal alignment as if on the bike; and do this checking at many places of the stroke.  Occasionally fairing parts are found to be the cause for vibration, and noises.

There ARE mechanical things with the driveline that can cause rhythmic vibrations. Usually an experienced wrench can determine, from speed and modest riding tests, where the vibrations are coming from. One of the high frequency vibrations that is difficult to figure out is from a driveshaft of the type with two U-joints, that was installed with out-of-phase U-joints.   See my
http://bmwmotorcycletech.info/phasing.htm article.

SOME vibration/thrumming can be serious, such as a loosening nut at the nose of the rear drive (which often produces no symptoms until serious damage is occurring); an internally failing cardan bearing, a failing transmission, etc.  Phasing problems are usually more constant, same for internal problems.  MANY times, changing speeds will help identify a vibration or thrumming; sometimes changing the transmission gear helps; sometimes pulling in the clutch lever, and other common experienced Wrench's tests.

 


NOTES:
 

(1) Modifying the rear fender, rear sides & rear bottom on some Airheads, can make for MUCH easier tire/wheel removals.  This is easy to do, can be done so no one notices. The rear fender, a composite material, is relatively easy to cut with a hacksaw blade in a single blade holder, & easy to smooth that cut edge with a common file.  Using a piece of chalk (or?), mark the fender from the side opening, downward/rearward, smoothly, to the bottom of the license plate.  Do on both sides of the fender. Cut and smooth.  When done, the fender should end approximately at the lower edge of the license plate. 

You can, not necessary, install a rubber mudguard (mudflap), such as from JC Whitney...or the ones I prefer, the BMW ones (pricey though). Note that fitment years shown below is not absolute, you may be able to use any of these.  Differences include whether or not they are complete with hardware, or have BMW emblems.
    
White, now no longer available unless you find a dealership with some:  46-62-1-239-274, fits from 9/78.
Black, 46-62-1-236-384, up to 9/78
Black, 46-62-1-230-766, up to 9/78
Black, 46-62-1-230-797, from 9/78
Black, 46-62-1-238-996, from 9/78

Check the dealerships' on-line parts fiche for number & fit/model; those numbers may be superseded or obsolete.  

If you do the below fender cut smoothly & neatly, and clean your cut nicely; it will probably not be noticed by anyone as not being stock. It makes removal of the rear tire easier on the twin shock machines.  DO NOT that the cut ends at the bottom of the license plate, that is masked by the mudflap in the below photo.

This is a photo of my 1984 R100RT that had the fender modification, including a mudflap.

 


(2)  Those with Reynolds Ride-Off center-stands, or, oversize tires, etc., will have to fashion their own methods for tire removal, as the front tire is typically on the ground at the same time the rear tire is, making for difficulties when trying to remove the front wheel for a rear tire flat; that is, for tilting the bike forward as described earlier.   Parking the bike so the front wheel is over a curb, with the bike on the center-stand, is one idea...DO tie the center-stand to front exhaust pipe; or, see earlier ideas.  I saw someone at a campsite with a tire problem who put the REAR wheel over a 'curb' to remove it....he had tied the front wheel to the ground using heavy duty tent stakes and some rope!

At home, you can jack the bike in some fashion that works well.  I typically use a board under the center-stand for tire work on Reynolds Ride-Off stand equipped bikes.   See notes much earlier, about half-way down in this article. With a stock rear tire, changing the front tire to an oversize type, can cause such problems.

(3)  The Chitech folks have a booklet on doing tire changes. Good information, but rather obsolete in SOME ways now. 

(4)  Tire Pressures:
The BMW factory recommended tire pressures for your early Airhead....certainly prior to the mid-1980's...is VERY probably too low for nearly 100% of tires available today for your bike. 

For the CLASSIC BMW airhead ride, use the stock sized tires, in the old ribbed designs....with the original manual-stated (or under the seat label) pressures.  These pressures are NOT correct, IMO, with modern tires, particularly on pre-1985 bikes.  Not many of us ride on the original ribbed front tires any more.  They do tend to follow rain grooves, contrary to what is said in some Clymer's publications. Still, you MAY want to try a SET, as they DO deliver the classic ride & handling that the 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 (by 2 psi front, 3 psi rear).   Also note that these tires DO give decent mileage before they wear out.   If you have a modified suspension, the classic ride & handling will be modified.  I suggest the Continental RB2/K112; but Metzeler is re-making classic tires now, and they are not the only manufacturer's.  See my tire testing article:  http://bmwmotorcycletech.info/section5.htm

By the nineties, the BMW recommended pressures were OK....not necessarily perfect....but often correct-enough.  You will probably find that for modern tires the appropriate pressures are LOW-thirties for the front and high thirties to even as high as the sidewall limits for the rear.  Tire pressure needs varies with loading (are you heavy? two-up?) & speed you might travel at.  

FOR YEARS I have been telling people that the tire pressures printed in your owners booklet, and in various literature, and very particularly so for BMW's made before 1985, after which tire pressure recommendations are a bit more reasonable, are much too low....for modern tires.  

At the end of this paragraph 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 pages.  This is one of the very few tire pressure guidelines that 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 THE TIRE MAKER'S TIRES!   AVON MOTO HAS BEEN KEEPING THIS ARTICLE CURRENT, AND ADDED MOST BMW MODELS, INCLUDING AIRHEADS!   IMO THE PRESSURES ARE VERY CLOSE TO MY FINDINGS FROM TESTING!!!! 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 on many tire makers!    I HAVE FOUND NO OTHER HONEST REPORTING LIKE THIS. 
 
http://www.avonmoto.com/tech/tire-pressure-guidelines

BE SURE to click near the top to select BMW in the small box.

MANY, if not nearly all, 'modern' tires require considerably higher pressures than stated on the tag under the seat or in the owner's manual or even in tire manufacturer's literature.  Failure to increase the pressures will cause very sloppy 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 TIRE MANUFACTURER AND TIRE INDUSTRY USES. There are certainly occasions where you may be using that maximum...such as on the rear tire, with maximum loads and high speeds.

The tire pressures shown in your early owners manuals are likely too low for MOST ALL modern tires. This is particularly so for the models before BMW changed the front wheel from 19 inches to 18 inches; as a general rule, all bikes before year 1985 have too low a recommended pressure for modern tires. You can probably just assume that information on pressures were TOO LOW.  Using too low a pressure leads to mushy handling, shorter life, and less crisp handling.

You can POSSIBLY determine the proper pressure for the tire, weight, speed, etc., of your type of riding, by measuring carefully the pressure before and INSTANTLY after a decent ride at cruising speeds.  The change is small, on the order of about a pound to 4 pounds (extreme conditions) and hard to read accurately.   MY Rule of Thumb of 6-8%% rise is proper after a fairly decent ride length, especially at goodly speed, and if less than 6%, DEcrease pressure, and vice versa. SOMEtimes this rule of thumb does not work well, and it appears it does not work too well with very stiff sidewall and some belted tires, which have less increase in pressure. This tire pressure measuring is tricky, and best you do not try; the method is listed here because it was so wide-spread in publications.

Using TIRE manufacturer's own recommendations USED TO BE more likely to be correct than BMW's recommendations.  Some manufacturer's KNOW that BMW pressures are too low but are UNwilling to take on liability by publishing their own recommendations if different.  SOME manufacturer's had the higher recommended tire pressures in their literature, and around year 2000 or so, changed to the BMW recommendations...probably lawyers were involved.     MY recommendation is to adjust pressure by FEEL on the road, and to NOT use the pressure rise method....  OR, use MY pressure information, which is just a bit below:


BMW owner's booklets, and books like Haynes and Clymers, usually show BMW's recommended tire pressures for the recommended and standard tires at the time of manufacture.  At times, BMW issued Service Information Bulletins (SI's) on tire recommendations.   BMW sent SI's on tires to dealerships for quite a few years during Airhead production.  BMW quit recommending tires for Airheads a long time ago. It is IMPORTANT to realize that BMW's tire pressures were always a compromise. It is also IMPORTANT to realize that most of the early types of soft sidewall tires are NO LONGER MADE.  BMW's compromise was between comfort, handling, and tire life.   BMW continued this practice, more or less; up through the ~1985 model year, and to a smaller extent, to the end of Airhead production.  From ~1985, pressures are more realistic for better handling, particularly by the 90's, although some advice & experience will help.  Typically improvements are still made for handling by some increase in pressure.

Because of these things, IN GENERAL, BMW's tire pressure recommendations in their owners booklets (duplicated by such as Clymers and Haynes), before 1985/1986, are OFTEN MUCH TOO LOW. All this is in MY opinion; but substantiated by others.   PARTICULARLY with modern tires.   I suggest you be VERY cautious about even trying BMW's old pressures, which were in the high twenties for front tires, & low thirties for rear tires.....depending on load and speed.

>>>>You can do your own testing, starting at low, or high, pressures.  I suggest you start with higher pressures, perhaps 36 front and 40 or 42 rear.  That way, you may get a better feel for things.  Consider speeds, loading (2-up? heavy?).  I think you will find that FRONT tire pressures of about 33-36 will be correct; REAR 38-42, all for most conditions and situations.  The highest of those pressures would be for high speeds and/or high loads, or very aggressive heavy riders in twisties. Pressures are always measured with a KNOWN ACCURATE gauge, tires cool (that is, UNridden, & NOT sitting in hot sunlight).

Lest you think I am making unfounded guesses, I ran across this link in 2014:

http://www.avonmoto.com/tech/tire-pressure-guidelines   
BE SURE to click near the top to select BMW in the small box.

More information on tire pressures and a lot more are in:

http://bmwmotorcycletech.info/section5.htm, and, for wheels, in http://bmwmotorcycletech.info/wheels.htm

(5)   Here is a FUN photo of not just simple studs, but extreme studding, used for ice-racing, etc.  This particular photo is of a front wheel.  I may eventually add more information here, on all sorts of studding, chains, ropes, etc.  for front and rear. Some photos of snow weather with various tire straps, etc., is likely in my photo galleries on this site already.
        

 

       
 

 

 

 

 

 


 


Rev:  
07/26/2008:  All prior updates incorporated, and article revised extensively this date
12/28/2008:  Edit for clarity.  NO substantial changes.
11/01/2010:  Expand on #5
02/19/2011:  Revise numbering, add section on exactly how to repair inner-tubes
04/11/2011:  expand on why I dislike CO2 cartridges
08/29/2011:  Add info on bestrestproducts TireIron BeadBrakR, inadvertently left out of this article several years ago!
03/16/2012:  update slightly for clarity
05/03/2012:  Add photos for second method of tilting motorcycle forward.  Clean up the article in various places.
10/15/2012:  Add QR code, add language button, update Google Ad-Sense code, modify photo, other minor stuff.
12/15/2012:  Add photo of studded front wheel at item (10)
03/11/2013:  Minor improvements to the article. Add entire section on how/why flats occur.
04/22/2013:  Add more on tire pressures.
04/24/2013:  Add more information on difficult-to-mount tires. Revise whole article for better clarity.
04/25/2013:  Additional tests proved that some couplers & excessive hose lengths DO detract.  Added the information & did extensive final editing on all parts of this article.  Sometime in 2013 removed language script and button.
05/26/2013:  Add Tusk inner core valve stem tool description and photo, and revise section i.
07/02/2013:  Add section on vibration/thrumming
09/26/2014:  Clean up article.
11/02/2014:  add link, comments, etc., to #4
04/05/2015:  Add section on comments made to the airlist this date
05/25/2015:  Add more commentary about Stop'nGo plugs, and steel plies in tires, pros and cons.
05/29/2015:  Begin incorporating items from catch.htm, tools, etc.
06/01/2015:  finished
06/02/2015:  Revise section on mudflaps
06/19/2015:  Add Slime photo and text
11/15/2015:  Clean up SOME.  Add some links, especially to BestRestProducts. 
12/24/2015:  Update meta-codes; change entire article to larger fonts; justify more to left; narrow to display better on small screens. Make tables to keep text & photos aligned.
04/05/2016:  Update meta code, layout, table, fonts, colors, eliminate/reduce redundancies, fix justification to left, etc.
10/29/2016:  Expand avonmoto information

Copyright, 2013, R. Fleischer

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Last edit of THIS page: Saturday, October 29, 2016