NEED FAST INFORMATION???:
For fast advice on the Web, try the Yahoo sidecar LIST ... see information in the http://bmwmotorcycletech.info/sidecarbasics.htm article on this website, and in http://bmwmotorcycletech.info/url.htm
There are other manuals, etc., available from various sources, such as the USCA. One is called Driving a Sidecar Outfit ...often called the Yellow Manual. There is also one that was a translation from German that has a lot more technical information, called "Riding with a Sidecar". This was translated and is available in America ...THAT ...and some other quite valuable additional materials was available from Hal Kendall, long before he passed away ...who had a LOT of information (4 manuals) available on ONE CD he produced ...which UPDATES that manual ...or, better said, is the updated manual. This CD is entitled: Sidecar Manual, Sidecar Operator Manual, Sidecar Catalog, Riding with a Sidecar. I have no idea about the CD availability, although maybe someone has one that could be duplicated. The same information is available free, all 4 of the books, athttp://www.sidecar.com/links3.asp
The information is also available for free at:
The serious sidecarist REALLY SHOULD own at LEAST Hal's CD, or print out the information from the above website.
Here is a link to the Evergreen sidecar training organization: LICENSING and OPERATION: Authorities of various sorts are INconsistent in fee structures for sidecar outfits for such as toll use of bridges and the like. Some Authorities, or automatic in-pavement sensors, are very confused by three axles. Many sidecars have the sidecar wheel ahead of the rear tire of the tug....called the LEAD amount. That makes them THREE axle. Harley's and some others may have their sidecars with the axles in line with the tug. Tolls are often based on the number of axles. Some sidecarists have had this clarified with their State Authorities, many have not. Dr. Hal Kendall took it upon himself to be very vigorous with the various Authorities on this situation. I am no longer listing his contact information in this article, as Dr. Kendall died. Requirements for helmet use is a bit muddled. In California, before ~1981, helmets use was complicated due to the number of axles ...due to a definition of the old Class 3 license being necessary for 3-axle vehicles grossing less than 6000 pounds. I won't get into this further here, as it is no longer the situation. In California, which is the State I am most familiar with, LICENSING of sidecar drivers is NO LONGER complicated. This came about, finally, after requests from such as Doug Bingham. Doug took DMV-appointed "Raymond Soon" for some hack rides. Mr. Soon was appointed to investigate the problems. Finally, around 1981, it was straightened out ...and spelled out in law ...and interpretation of law. Before this, the DMV and CHP had not agreed on things between themselves, let alone others.
The licensing requirements for operating a sidecar outfit varies from State to State; and around the World. Besides the licensing requirements, the way Authorities treat sidecar operators in other ways can vary. Here are a few things of possible interest:
After they all agreed upon laws and interpretations, a sidecar rig could be driven with a Class 3 license ...which INcluded Class 1. Confused? These classes were all changed, so, enough on those.
LICENSING and OPERATION:
Authorities of various sorts are INconsistent in fee structures for sidecar outfits for such as toll use of bridges and the like. Some Authorities, or automatic in-pavement sensors, are very confused by three axles. Many sidecars have the sidecar wheel ahead of the rear tire of the tug....called the LEAD amount. That makes them THREE axle. Harley's and some others may have their sidecars with the axles in line with the tug. Tolls are often based on the number of axles. Some sidecarists have had this clarified with their State Authorities, many have not. Dr. Hal Kendall took it upon himself to be very vigorous with the various Authorities on this situation. I am no longer listing his contact information in this article, as Dr. Kendall died.
Requirements for helmet use is a bit muddled. In California, before ~1981, helmets use was complicated due to the number of axles ...due to a definition of the old Class 3 license being necessary for 3-axle vehicles grossing less than 6000 pounds. I won't get into this further here, as it is no longer the situation. In California, which is the State I am most familiar with, LICENSING of sidecar drivers is NO LONGER complicated. This came about, finally, after requests from such as Doug Bingham. Doug took DMV-appointed "Raymond Soon" for some hack rides. Mr. Soon was appointed to investigate the problems. Finally, around 1981, it was straightened out ...and spelled out in law ...and interpretation of law. Before this, the DMV and CHP had not agreed on things between themselves, let alone others.
Today, California has two types of motorcycle driver's licenses ...two CLASSES as they call them. TWO-wheeled motorcycles require either a Class M1 or M2 driver's license.
Class M1: Can operate ANY two-wheel motorcycle rated at 150 CC or more ...and may operate all vehicles listed under M2.
Class M2: Can operate ANY two-wheel motorcycle rated at 149 CC OR LESS, or a vehicle called a 'motor-driven cycle', or one called a 'motorized bicycle'. Those two types are spelled out as to their meaning in the codes. NOTE! ...People driving in California often see, on freeways, a sign prohibiting Motor-Driven Cycles. Basically it means if you have 15 or more horsepower, you are OK on that road, and if less than 15 horsepower, you are a forbidden Motor-Driven Cycle.
Here's where it gets to be fun ...or, at least interesting! .....>>
The Class-C car driving license....the one most everyone has ...has specifics about axles, trucks, gross weights, and so on ...but ...regarding sidecar rigs ...it specifically states that this license "Class-C" is OK for operating a motorcycle with a sidecar attached ....""OR a three-wheeled motorcycle"". DMV defines these terms, elsewhere's. Thus, trike's are covered, as are sidecar rigs.
A motorcycle with a sidecar attached requires only a regular Class C driver license ...the same license needed to drive a car in California. I personally have both a C and an M1 license. I can drive a motorcycle, a sidecar, a trike, and some trucks ...besides cars.
In California, all motorcycle riders and passengers are required by law to wear a legally approved helmet. There is NO provision in the law to EXclude sidecar passengers ...note, again, that the definition of a motorcycle includes sidecars, but LICENSING of operation spells things out as above. If you are confused, read the above 4 paragraphs again, imagine yourself with a car license, driving a sidecar rig, etc.
Sidecar folks sometimes use rear tires on the front of the tug, with the directional arrow, if present, reversed. This is acceptable practice, even admittedly so by such as Metzeler. It is possible to seal a tube stem via rubber washers and exterior nut to the rim to hold air better, if the tire/tube is punctured. But, that must be offset with the knowledge that if the tire rotates any on the rim, it could rip the stem out of the tube. Understand that the real reason for the stem nut is for help in installing the tube, then to be NOT used ...or to be up against the valve CAP, NOT the rim. Up to you. I've sealed stems, and I've used tubeless function on tube rims, and all sorts of combinations, on sidecar rigs.
BMW makes a special all-metal valve stem that fits in original tube-sized-valve-stem holes, but is for tubeless tire use ...and it comes with the core, metal cap, nut ....and rubber O-ring, as part 36-32-1-452-748. A NICE part! This type of part is available at 1/3 the price, elsewhere's. Some rims are not flat on the inside, and will require spot-facing for this item, some spot facing will leave the rim too thin, so a rubber washer is used.
Sidecar folks sometimes do all sorts of things that are not necessarily considered OK on a solo two-wheel motorcycle.
Here is a link to a rather nerdy article. The article has extensive vector & other diagrams, & some conclusions about contact forces that may well surprise you. When you read it, keep in mind what REALLY happens when you are cornering. THINK about the effects of you changing a tire size ....from, an example here, a 90/90 to a 100/90. What REALLY happens when you go to a larger size tires (larger width). What are the differences between motorcycle and car rims. ETC. You may be very interested.
That article is quite nerdy in places, but has some real jewels of information here and there. It really is worth the FULL read, as many of the information jewels are later in the article.
Photos of my 1983 BMW R100RT WITH URAL SIDECAR.
Other views are in http://bmwmotorcycletech.info/photogallery.htm
The tug has a dual-plugged engine and raised compression ratio, the front forks are UNIT brand, with stock dual Brembo brakes. The rear drive is 3.36:1. The rear brake is the stock single Brembo disc brake. Front wheel size is 19 inch, rear wheel size is 18 inch. Rims are stock. I have two rear wheels available, one has road rubber, the other has an Enduro tire. The sidecar tire and rim are stock Russian Ural items, 3.50 x 18. The left side of the tug has a Luftmeister 1 gallon auxiliary fuel tank. A very long list of other modifications have been made. The fairing is stock BMW "RT" type, and the lowers are still in place, although the right side one is modified for the upper strut of the sidecar attaching. The attachment to the tug is via a subframe of the Lowell Neff style, somewhat modified from his design. Even though of steel, the joints and fitments were HELIARC'd. There are two upper struts and two lower ball mounts. The subframe, photos later herein, picks up numerous points on the tug frame. There are some frame beef-ups on the tug, nothing major, but what WAS done was deemed important. There have been ZERO problems since this rig was put together in 2001.
The photo below is of me, at one of the Griffith Park Sidecar Rallies. This older photo is from back when we could camp overnight there.
Below photo was taken January 12th, 2005, a bit over two months before a much nicer spare tire carrier was installed.
BELOW is a view of the added hack brake pedal, made from a salvage yard aluminum BMW pedal. I cut off the L section from the left side of the pedal, and welded it onto the right side of the added pedal. A long piece of steel round rod was added to the sidecar brake rod angularly under the sidecar for additional strength; ...the angle was to help to avoid any bending, then that rod was welded to a somewhat shortened Ural slotted lever, and then bent downwards and then extended to the left, towards the bottom in this photo. The rod then had an additional round rod welded to it, for the BMW stock brake pedal to push against. Note: the added modified pedal presses only on the Ural's brake rod. The tug's brake pedal presses on that too AND actuates its own, stock, hydraulic cylinder.
Thus the two brake pedals are independent ...BUT, in a special way. You will need to read at least five more paragraphs to understand how the special function operates. I was pretty proud of myself after figuring out how to do it.
Normal stopping is done with the tug's stock pedal, which applies LIGHT BRAKING to the sidecar wheel at the same time. If the other pedal (the added one, the top one in this photo) is used, the sidecar braking is done separately, and gives as much braking as desired, independent of use of the tug brake. This can be very useful for tight right turns. NOTHING keeps you from actuating BOTH pedals at the same time, either, but this isn't needed. There are some 'fancy' maneuvers possible by using these levers in special ways, to allow rear wheel slides, etc. Not going to get into that here.
The mounting for the added pedal is a special shoulder bolt, to maintain a tight assembly without noticeable play. A small spring keeps the pedal from vibrating, at its tip, onto the brake rod. An adjustable stop, hard to see at the top here, sets the amount of distance the pedal is off the brake rod.
BELOW is another view of the dual pedals, and also showing the upper rear strut. The pedal on the left is the stock BMW pedal for the rear brake. Actuating the BMW rear brake (left pedal in the photo) applies the rear BMW brake and also puts pressure onto the horizontal sidecar brake rod you see in the photo, but the sidecar brake pedal activates only the sidecar brake. The hack pedal came from a BMW junkyard, and its toe-plate is a bit different, it is centered, not offset ....but any version would do.
Not shown is the underside of the right pedal. I modified the underside profile with a common file, so that the sidecar brake will have limits. That means that once the sidecar pedal has been pushed hard/far enough, the rod slides under the pedal and no more braking can occur. This is handy in special circumstances. I calculated the mild cam-shaped slope of the underside of the pedal to get the maximum braking I would ever want.
Due to the normal stock limited travel of the BMW pedal on the left (particularly with tug that has a disc brake like this one) and careful adjustment of the Ural brake adjustment nut (on the Ural wheel brake rod), it is not possible to lock, or overly brake, the sidecar wheel, from the BMW stock pedal on the left. This worked out PERFECTLY! Thus, this setup is 100% mechanical without ANY tug rear disc brake hydraulic connections, and very reliable, for braking of the sidecar wheel. This SAME sort of thing would be easy to do on a BMW tug with drum rear brake. In essence, I have a somewhat sophisticated brake controller & 100% reliability, as opposed to hydraulic proportioning valves, a hydraulic brake, ETC. ...NONE of which is necessary!
Below is the very sturdy subframe that was built for the right side of the R100RT. The upper portion at the top of this photo fits the ADDED cross piece above the stock area battery. The lower part, horizontal, attaches to the rear frame, the rear footpeg, other places, and to both engine bolts. This is a Lowell Neff type design. It is extremely strong.
NOT pictured: the upper front mount, which mounts at the BMW frame cross piece, just under the steering head. There are TWO ways of doing a upper front mount there, one is welding, one is a special sturdy clamp. I dislike welding on the BMW frame, and used a clamp ...in fact I purchased mine directly from Lowell Neff. It places front strut forces directly into the existing, stock, BMW frame AND BMW STOCK CROSSPIECE.
Below are some views of the struts; steering damper setup (with several hole adjustments), front and rear lower mounts, and a rear view. The clamp and plate assembly for the steering damper was made with several holes, so it could be made adjustable for stroke and other effects. The damper is an inexpensive VW type, used by many sidecarists. I believe most who use them do so wrongly. I'll explain further on.
There is only ONE Heim joint needed with my mountings, and the sidecar upper strut end of the damper has the stock damper's rubber mount in the 'eye'. Originally two Heim joints had been tried, but I found this to have, due to the complex angles of use, too much movement before damping began. I spent a fair amount of time was spent getting just the right angles and clamping, so I could eliminate one Heim joint. There is ZERO instability, no wobbles, etc. There is also NO excessive damping ...again, I will explain it later herein.
The stock BMW hydraulic steering damper still exists, but is not powerful enough, hence the VW damper. It would be possible to set the added damper mounting plate holes further inward, for LESS stroke, and less steering effort, if the BMW damper was turned on to position 1 or 2. Dampers, whether hydraulic or friction, are always a compromise, too much damping (over-damped) makes for heavy handling, too little (under-damped) can allow the front end to oscillate badly. Each rig is different. The MINIMUM damping that does the job is VERY MUCH preferable.
The VW Beetle damping unit is used by a LOT of sidecarists, primarily because it is inexpensive, functional, and easily available with multiple types of ends. It is important that it be used correctly, or poor return of the steering to straight ahead will be had with stiff steering (that means higher human forces needed). For some adaptations, use of the Beetle damper, NOT Super-Beetle, may be better ....for some, the Super is better. The VW standard Beetle damper can be attached to some tugs by replacing an upper shock mounting bolt ...with a Heim attachment. Try to avoid using two Heims in your installation, it often gives rise to excessive movement before damping. The end of the standard most commonly available Beetle damper is 10 mm, and if one can not get a 10 mm threaded Heim ...sometimes hard to find ...then one could consider using a 3/8" Heim, and run a 3/8-24 tap over the 10 mm end. The other end of the damper attaches to the front strut ...you can weld on a tab, or use a clamp, or whatever is really needed.
In MY installation, I use the standard damper end of 90 degrees as shown in the SECOND PHOTO. I bolted a standard threaded post Heim to it, and the strut end is fitted to a bolt-on clamp (after all, the strut needs adjustability). I kept the rubber bushing in the eye of the damper, it was needed. As noted earlier, originally I'd tried two Heim's, one at each end, but this allowed excessive movement before damping began...and, tiny as that was, it made me have to use an attachment hole on the fork clamp ...see photo ...that was too far away from the fork, and whilst that gave enough damping stroke action, it also increased the EFFORT for steering. By carefully aligning the design, I eliminated the eye end Heim, moved the attachment at the fork closer to the downtube, and that reduced stroke amount per steering amount ...a NICE effect. For those that can eliminate the rubber bushing, you will be even better off.
The two special Hagon shock units for the tug's LL fork have some adjustment by the upper shiny collar. I found the lowest setting just fine. At the upper center area is shown some of the stock BMW oil cooler. The shocks and spiral wrapped SS brake lines all came from Heddingham (UNIT FORKS) of England. Spring and damping of this sort of design should be such that under VIGOROUS braking, the suspension NEVER extends to rock-solid limits. If that happens, the front tire and braking will be 'skipping'.
Note the damper mounting clamp-plate assembly in the first, below, photograph. Note that the damper Heim is in the third hole from the end, that is, it is in a very close-to-fork tube position. It gave enough dampening, without making the steering too stiff. Use of a square front tire, the Avon Triple Duty Sidecar tire, installed AFTER this photo was taken, allowed me to move the pivot one hole further inwards, for less damping via a shorter damper stroke per forks movement. This resulted in lower steering effort, even considering the INcreased effort usually coming from such a flat tread tire. Yes, this photo is hard to see/understand.
The clamp(s) at the top of the Hagon shock/spring units are adjustable up and down on the UNIT front ends. This changes the TRAIL! & also the angle of attack of the lower arm of the leading link ...that has an effect on how the tire, and front end, is affected by oncoming road items.
All that speckling on the fairing lower is sand and gravel pitting, primarily from motorcycling trips to Alaska on gravel roads!
There is a VERTICAL beef-up plate that is hardly visible just barely to the left, underside, of the two clamp bolts. This may be way overkill, but made me comfortable with the strength!
BELOW shows the front Ural mount, notice the additional bolt on it! (see red lines). Installation was done in such a way as to INcrease the track width by about 3 inches; for easier access to valve adjustments; ...see later photo about the rear mount. The rear mount is similarly beefed with an additional bolt. NOTE that the stock Ural front mount is NOT adjustable. I cut that one off, and obtained another rear type (there are at least two versions, they all can work OK here at the front), and notice the beefed-up horizontal angular plate that was added (red line with an arrow).
The next two photos are of the right side of the tug, showing what I crudely did to the right side lower fairing piece. The first photo shows that I cut this piece vertically, so there is a REAR half and a front half. For the purposes of this photo, I put something (hidden) inside to move the rearmost part outward slightly, to better show the cut, in white here, but with a red line and arrow also. By unfastening at the bottom fasteners that go to the stock metal bracket (not shown), and at the top (see second photo, inside area, where I made a simple beef-up plate), the parts are removable without having to remove the strut, bottom mount, etc. I'm not proud of this "workmanship"!...but it was my experimental rig, not what I later did for customers. I had numerous people tel me that I could not 'keep' the lowers, and even if I kept the fairing, it would disintegrate from the road vibration, etc. They were wrong, and I have a LOT of VERY rough mileage on this rig, including on boonies trails on National and State forest roads, designed for horses, not vehicles....very rough stuff, including climbing over rocks and tree limbs, big ruts, etc.
Below is of the inside beefed up area that also allows easy removal of the fairing piece that has that vertical cut in the ABOVE photo; it is all crudely done, but effective. Once I perfected everything on this rig, the next one I built, for a customer, had MUCH nicer-looking workmanship. This view is from above.
This view, below, shows the extension piece that was made up, that allowed the wheel lead to be reduced to 6 inches, a rather low amount, but one that is very easy on tires and has the very quick handling that I personally prefer. The drawback to such a short wheel lead is that one must be more cautious about overly-vigorous turns away from the sidecar, lest the sidecar nose go over and dig in, a very BAD thing to have happen! I do NOT recommend that most folks use 6 inches of lead on this type of rig. 9" or 10" would be safer for them. The photo might lead you to believe that the extension is not parallel to the hack and bike frames, but that is not so. NOTE the additional bolt on the Ural sliding mount. These modifications were done (and the front mount too!) such that the TRACK WIDTH of the bike-to-sidecar, was also INcreased, by roughly 3 inches. That allowed for the proper access for servicing, and also I felt would make for somewhat more stable driving on common road track widths. The former more important than the latter. So, that rectangular metal addition added rig width, AND set a shorter wheel lead.
This was the initial setup, with the Ural fender rack & rear rack. I am carrying a spare front tire here in this photo.
Below is a photo of the final modification of the above mount, rack, etc., completed 03/19/2005, that enabled me to carry a spare BMW snowflake rear disc wheel/tire. I can put another tire on top of the rack, or lots of luggage. In order to do this, and preserve the use of the neat-looking Russian cap, the Russian welding at the bottom of the mount was ground away, and a 6 inch long metric 8.8 grade bolt, with the same end threads as the Russian cap (12 x 1.75 mm), was welded from the bottom upwards. The stock large thick Russian washer under the mount was first drilled with a large drill that was just a bit larger than the diameter of the bolt's head, this allowed the bolt head to be recessed nearly 3/4 of its head thickness. That eliminated any chance the bolt would contact the trunk lid, and added a bit of length to the bolt, which I found was needed. I then welded the bolt head to the Russian washer. A spacer was made for the wheel bearing axle opening in the wheel, so that the wheel would not move about on the long bolt, as the wheel bearing inside diameter was considerably larger than the 12 mm bolt. That spacer was made from an old piece of chrome luggage rack round tubing. A thick flat spacer, counterbored to fit the BMW internal axle spacer, which sticks up slightly from the bore, was used between the wheel's disc hub, and the underside of the Ural rack. This made for a VERY neat installation. On the Ural chrome rack on the fender of the sidecar is a 2-1/2 gallon plastic fuel container I sometimes travel with. It's weight is just where sidecar weight should be ...over the wheel! I can put a much larger Jerry can there, if I wanted to. A 5 gallon Jerry can and fuel would likely weigh about 40 pounds, and be the equivalent of considerably more sidecar passenger weight, and the rig could then be expected to NOT lift its wheel in right turns very easily at all. The Ural chair is heavy anyway. The ride, for a passenger, was very comfortable with the stock Ural suspension system.
More photos below: The first two photos show the round solid steel spacer that allows sidecar upper rear strut forces to the right side of the tug frame to be shared by the left side of the tug frame, via that added spacer. This spacer is located over the battery area, using EXISTING and UNused BMW frame tab holes. The spacer has a flattened area for a wrench, that you cannot see in the photos....otherwise, tightening the end bolts could, perhaps, cause the tube to rotate. I never needed the flattened areas.
A problem now exists ...the stock tool tray occupied where the spacer was installed! ...so, below was the first try at a 'crudely' modified battery tray. I'm not proud of this "non-workmanship"! ...but it was my experimental rig, not what I later did for customers. Surrounding that jagged hole and not easily identified is an aluminum sheet metal piece that is inside the tool tray, it is riveted and then sealed to the inside base, so tools, etc., can not fall out of the tool tray. I have, since, made vastly nicer versions, one was a new fiber-glass tray from a mould I made. The fanciest one I made, wish I had kept a photo, was made out of a solid block of metal, on my mill, and is an artistic gem. I spent an entire weekend making it for a customer, and then even anodized the surface. The cover was also of metal, and used a short 'piano hinge' design. I should have made it all on a CNC mill, and kept the programming.
Notes on Setup and Alignment:1. One of the very first things to decide upon when first starting any sort of assembly of a rig, is the amount of wheel lead, if any. Wheel lead is the amount the sidecar wheel axle is forward, if any, of the tug's rear wheel axle. Early rigid frame tugs, such as the Harley Davidson, using Harley's sidecar, can use zero lead, and most were like that. A racing outfit might use as much as 15 inches.
With zero lead, there is little scrubbing on the tires on turns, but weight distribution is poor, and any tendency to nose over (rear wheel lifting on turns away from the sidecar) is worse (the rigid frame tugs are much better at avoiding that). Added weight to the front wheel is poorer for handling. If the tug weight is massive, the tendency to nose over is lessened. As the sidecar wheel lead is increased, the sidecar wheel takes more load, & the weight on the front wheel is reduced.
As the sidecar wheel is moved more and more forward, the more tire scrubbing you get on turns. In fact, the sidecar wheel direction can REVERSE during turns if too far forward.
As rear suspensions improved over many years, they became less rigid, and the modern swinging arm was developed, & sidecar lead needed to be increased. It is rather typical on a good handling and good compromise (tire scrubbing, ETC.) rig, for the sidecar axle to point to the front edge of the tug rear rim. Further forward gives better weight distribution but more tire wear. Further rear eases turning effort and less scrubbing. Ideally, the lead should be as small as possible from several standpoints, BUT NOT ALL. It is from all these practical operating condition facts, that I said that the sidecar axle typically leads, for a street rig, the distance of axle to front of rim of the rear wheel on the tug.
2. The sidecar frame should be level, as measured on a level surface. That is, the sidecar wheel side of the sidecar frame ...and the sidecar frame portion towards the tug, should be LEVEL. Measure this with normal weights in the sidecar and on the tug. In some instances, this level-ness is less important than the level of the sidecar chair; perhaps considering oncoming wind effects on lifting the nose of the sidecar at speed, etc.
3. Toe-in: This needs to be checked with normal loading of tug & sidecar, unless you find your rig's toe-in will be stable with weight changes. SOME toe-in is needed. It will help counteract the bias & drag of the sidecar due to the wind resistance and tire friction drag. Less drag means less toe-in can be used. Toe in is measured by many means, but is almost always measured off the rear wheel.
TOO MUCH TOE-IN DOES NOTHING BUT INCREASE TUG REAR TIRE WEAR. You may wonder if the sidecar tire will also then have increased wear. It does, but only to a VERY MILD effect. The reason is that the sidecar wheel is well-away from the tug, so a small force at the sidecar tire contact with the road, has a quite large effect on the tug's rear tire ...due to LEVERAGE, combined with sidecar wheel LEAD. In all the years I have been involved with sidecaring, I have NEVER seen this explained ANYPLACE! It is also not explained how the wear is different between left and right direction turns ...the difference being the tug pushing the sidecar and needing to overcome the leverage. I had two sketches showing how this all worked, and decided it was too nerdy even for this article, so never used the sketches.
Zero toe-in is generally a bad idea. While correct toe-in helps correct for any tendency for the rig to pull towards the sidecar (not enough toe-in), that is difficult for an amateur rigger to figure out. If you want to try, the correct toe-in is achieved when at about 30 mph on a DEAD FLAT ROAD, when there is no tendency to pull either left or right. The HUGE problem with this is that normally the tug is leaned OUTward, to compensate for road camber/tilt AND THE DRAG OF THE SIDECAR, and all this greatly complicates things, as does finding a truly flat road. I did a lot of testing in this regard, and decided I needed a very sensitive method of determining flatness of the road, ideally a truly flat road, & I also needed high sensitivity to any pulling tendency. I also need to make sure my tires were not going to influence my tests, etc.I came up with the idea of using a frozen lake! From that, I learned a lot. I have NEVER seen anyone else talk about this!
Best for most of you is to take careful measurements, set the toe to an estimated value, and work from there, slowly, ever so slowly, making small changes in toe and lean-out, ONE thing at a time ...until things are 'sweet'. Toe-in amounts are generally about 1/4" to 1-1/2", with around 5/8" for more rigid tug rear suspensions and 1" for longer throw tug rear suspensions, as probably good values. For my personal sidecar rig, a K1100LT pulling a large EML GT2 chair, I set the toe-in at a near minimum value, that gave good tire wear ...and that amount was slightly smaller than ideal for normal road paving camber, etc. I am using 3/8" unloaded, and it is about 5/16" loaded; that is as low as I dare go. I may yet increase it to 5/8". I am also using a wheel lead of 13-1/4". Note that I have car tires all-around. No way should these values be used on an Airhead-Ural rig with motorcycle or sidecar type tires.
PAGES could be written ...and have been ...about how to measure, repeatedly-accurate, toe-in, by inches, by degrees, etc. I won't get into it here. For toe-in, the measuring points are usually just ahead of the front tire, and just behind the rear tire. I did it originally with a piece of string stretched between two nails on a common 2 x 4 piece of lumber, one each of these for the rear wheel and the sidecar wheel. Nothing fancier is really needed. The string must JUST touch both sidewalls on each of both tug tires, and both sidewalls of the sidecar tire.
NOTE! As lean out is increased, turns away from the sidecar are easier, but the sidecar wheel will tend to lift much more easily for turns away from the sidecar, NOT a good idea! There is controversy over lean-out. Some use Lean-In ...depends on the rig. Toe-in affects the amount of lean-out to be used. Too small of a toe-in will cause you to use more lean-out, with a very noticeable tendency for the sidecar wheel to come off the ground in turns towards the sidecar. However, MORE toe-in results in more tire wear, as I described.
4. Finer-yet considerations:
(a). To help compensate for road crown, and reduce the need for excessive leanout (sort-of), consider having the sidecar wheel side of its frame about 1/2" higher.
(b). Consider having the front of the sidecar frame slightly higher than the rear
(c). Consider having a minimum 44 inch track (my K1100LT rig uses 53-1/2 inches, making it fairly wide)
(d). Consider that toe-in tends to dynamically change, that is, it changes towards LESS toe-in, as the speed increases, due to flex in all sorts of things.
(e). If toe-in is too little, there may be a tendency to drift towards the gutter.
(f). If a rig is well set-up, it will move slightly towards the curve with acceleration, away with braking.
(g). Some say that about 14% lead is best (of wheelbase). I tend to discount this.
(h). Lean-out is supposed to be used strictly for compensating for road crown. Be sure, if using a major multi-lane highway, to drive the rig in every lane, moving over slowly, to see the crown road effects ...which may determine which lane you will travel in.
The main reason for adjusting the lean of the tug is so that you do not need constant left or right pressure on the handlebars, at the typical speed on the typical roads that you travel on. Constant pressure is VERY tiring, your shoulders will thank you for a properly set-up rig. If you travel on all sorts of different banked and crowned roads, you may want an electrically operated adjustable lean control (or, effectively the same thing by adjustment of the sidecar suspension electrically). HOWEVER, a very properly set-up rig, which is also built stoutly, tends to not need them.
Adjustments to a sidecar rig inter-react with each other. Make small adjustments to ONE THING AT A TIME, to find the 'sweet spot'. There are some 'quickie' tests on your garage floor that can reveal some things, and here is one such:
Place a vertical stick or pole on the floor, almost touching the center, horizontally, of the sidecar nose. Have the nose of the sidecar an inch or so away from the stick. Place a bit of masking tape in the center of the nose of the sidecar. Have the steering straight ahead when you line up the stick and masking tape. HOLD the REAR brake, and turn the bars full left, and then full right. What happens to the relationship between stick and masking tape, and, do you know WHY, and what it MEANS? The answer requires some real thinking.
Every rig, properly designed and built, can have a SWEET SPOT ...where handling, control, pressures, feel, all come together. The sweet spot is often the same for good tire mileage!
Some very generally correct rules and comments for alignment are:
Toe-in affects pulling right and left (if it pulls to the right, an increased toe-in will help compensate). The very bad part of this is that if the toe-in is excessive, you gain nothing but rear tire wear, and rear tire wear with a lot of toe-in can be HUGE. For most common street-going rigs, toe-in over 1" is excessive, and I have found that most can do well with about 3/8" to 7/8". For initial setup, I have been recommending 3/4".  It is best to start with the toe-in on the high side, so using 1", which is typically the maximum for any street-going standard rig, may be better for you.
An issue NOT thought of by many, is that the condition of the sidecar wheel's suspension can have quite an effect on toe-in. Several ways. I will assume the bearing has no feelable play (if it does, fix it). I will assume the TUG suspension has no sideways movement either. Even things like weak or loose spokes in your wheels can have effects during turns. Both tug and chair suspensions may be mounted in deteriorated rubber; or have loose fittings in some way. Thus, toe-in can change while on the road, particularly with speed and wind changes. Suppose you have a dead flat section of road near you, a nice place to do test drives. Let's say that you find that you have 'perfect' alignment on your bike, as far as handling goes. You can almost take your hands off the bars, and the rig will go straight down the road. BUT, as you increase speed, while oncoming wind has almost no turning effect on your TUG ...it DOES push on the nose and body of your SIDECAR. That causes the rig to try to turn towards the sidecar. You will compensate by turning the bars away from the sidecar. But, that is a constant pressure on the bars. It is possible to set up a rig such that this type of effect is minimal, but it can take time to fiddle to get the rig that way. Everything dealing with sidecar rig handling seems to take TIME!
I well remember being frustrated with my 1983 R100RT-Ural rig after doing a lot of alignment work. It was too speed sensitive. Why? Gads ...why had I not thought about nose angle! ...yep, some quite modest change in the nose angle cured that final handling problem. After that, the only thing left was to decrease steering effort (and improve return-to-center) specifically caused by the too strong steering damper. I made an adjustable plate to allow adjustment of the shock absorber's STROKE used for damping. That fixed that problem. I now had a rig that I could put thousands of miles on in a tour, and be very happy. It took TIME to adjust things. ONE step at a time!
If the rig is not stoutly built, things may BEND, one way or the other, under pressure from cornering or even oncoming wind. Those things really put a fly in the ointment in trying to have a good handling rig.
Toe-in adjustments are, generally, a bad way to try to cure pulling (left or right). Tire wear is a strong reason, but not the only reason. That is why lean-in and lean-out are the prime adjustments for pulling right or left. Toe-in also has an effect on how hard the rig is to turn left or right. To most sidecarists (I think), they either don't know about this effect; OR, they can't feel it; or, think they can not. If the toe-in is excessive, that makes the rig turn harder away from the sidecar (left for most in this country). Toe-in affects some other things. If your toe-in is too much, not only do you scrub away tire rubber on turns towards the chair, but the rig might tend to drift towards the middle of the road ...and vice versa. If the toe-in is way too little, that you could find that you need way too much lean-out! Even your front brake will act poorer!! Guess what happens with excessive lean-out! ...yep, chair lifts easily ...and ...YOU guess!
Another thing that affects how hard it is to steer the rig, and even affects or causes PULLING! ...is the LEAD of the sidecar wheel. Here's another one of those things that few talk about. If the rig pulls to the RIGHT (towards the sidecar), the typical response is to change the LEAN of the TUG. However, DEcreasing the wheel lead will have a similar effect.
If the rig is hard to turn away from the sidecar; and hard to turn towards the sidecar, most think that they simply must have a leading link or Steerite, or, whatever, to reduce the TRAIL. Maybe they do not know that DEcreasing the wheel lead will do SOMEwhat of the same easing of steering ...and reduce pulling away from the chair at the same time. But, there is a limit to how far you can DEcrease the wheel lead, without leading to other niceties, such as the nose wanting to dig into the ground with overly-brisk turns away from the sidecar. NOTE that, generally, if you use MORE wheel lead, then you can use LESS toe-in. But, that is something to address MUCH later than at first. I prefer that the wheel lead be a good estimate for YOU, for YOUR type of riding. After all, you don't hardly need much toe-in anyway. If you need over an inch of toe-in, you have other problems with your design.
If the wheel lead is excessive, the sidecar wheel can actually reverse direction during turns, and scrub its rubber off not-so-nicely. Otherwise, on a properly set-up rig, the sidecar tire will likely last a HUGE number of miles. Generally, wheel lead is something you guess at, based on experience, and once set into the construction, it is usually very difficult to change, so most never try to change it. That is why I have made note of what the wheel lead should be for the average road-going rig, well above. Note that my discussion has not gotten into, much, about the straight-across NO wheel lead rigs, like some Harley's ...they are worthy of their own long discourse. I make an educated guess on wheel lead AND toe-in, when first working on a new rig. For rigs that do use lead, and they are not a rig for racing, I suggest keeping the wheel lead at the radius of the rear wheel AS MEASURED from center (axle center) to the rim edge. That will always be a bit more than the rated wheel size; which is not measured at the rim edge. That is almost always a truly good compromise between handling, etc. Thus, an 18 inch wheel would have a bit over 9" lead. More lead for a rig using car tires.
You can go too far with lean adjustments. As has been noted, if the sidecar lifts easily, you can DEcrease the leanout. But, you may not want to DEcrease leanout, perhaps because it causes the rig to travel towards the leaned-out direction. What to do?
(1) Toe-in can be under 1" on most every rig;
(2) ADD WEIGHT to the sidecar itself. The farthest point on the sidecar away from the tug, is the best point. To the REAR of the sidecar is VASTLY better than weighting the sidecar nose. This is really something that is VERY nice about sidecars ...weight HELPS handling, if the weight is centralized (or further towards the sidecar wheel, which is even better) and/or rearward. Some have even put a heavy metal, such as lead, inside a right side frame. A nice thing is to have a car battery at the chair. It takes up room if put in the chair's trunk, so some clever mounting might be needed. With today's no-maintenance batteries, putting one or two under the chair, toward the outside, is often very doable. You might even decide to eliminate the tug's battery. Reasons for and against, of course. Some put extra fuel underneath the sidecar, centered or slightly toward the rear or even a bit towards the sidecar wheel. Of course, as you use the fuel, that weight disappears. I was going to build a custom tank for vastly increased fuel on my Airhead-Ural rig, but sold it before I started construction. It was going to be 12 gallons, which would have been close to 100 pounds including the SS tank and mounts, down low, and well away from the tug. I would have been a real menace to Porsche's in the twisties!
Some rigs are just plain overly sensitive to alignment. By this I mean that adjusting one thing causes a quite noticeable effect on another adjustment. Most of the time this can be gotten rid of, with attention to details. It is amazing how many sidecarists are so LAZY that they will put up with an ill-handling rig, or with tire wear, or both; instead of taking the time, and it can be considerable, to get things correct. Some have probably given up on sidecaring, due to poor handling rigs. In general (I use that word a lot), I try to align a rig based on my best guesstimates, and then ...USUALLY ...the lean-in or lean-out is the LAST adjustment I hopefully have to make. I also might put force on the sidecar suspension, after a long eye-ball look at it ...to see if something is angularly moving, etc. A sidecar suspension that moves 1/8" in a direction you do NOT want is a VERY considerable amount, in effects.
Anyway, what all this chit-chat amounts to is food for thought, and hopefully improved handling and tire wear.
For Heavy Steering: DEcrease the front tire width. Your choice of automotive tire or motorcycle tire (or sidecar type flat tread tire) for the front, has a large effect on steering forces, and "some" effect on actual braking. Car tires on the front tend to follow road irregularities, sometimes quite egregiously and annoyingly, particularly on rain grooves. Having a car tire on the FRONT also gives heavy handling, that is, it takes a lot more physical effort to steer the sidecar rig. The front tire wears quite slowly, no matter what size it is. A lot of rigs could be improved by using a M/C front tire (or the Metzeler or Avon flat tread 'sidecar' tires) .... and an small automotive tire for the REAR, if possible. Many use the Metzeler K block or the Avon Triple-Duty, which are sidecar specific tires ...and they are often NOT the tire one should select. Just because a tire 'is made for sidecaring', does not mean it is the correct tire for that purpose. Since wear is not much of a consideration for the FRONT tire, I also see less real need for a flat tread tire at all for the front, and that includes the Metzeler K Block and Avon Triple-Duty types. However, the flat tread tires DO offer one thing, and that is a bit more stability; just as if a quite mild steering damper was affixed. I'd rather have a real damper and a real motorcycle tire, but am fine with either of these two mentioned ones. Think carefully before going to the effort and cost of installing a small car tire ...at least for the front. Of special concern for sidecar use is the steering head bearings. The steering head bearings should be set up TIGHTER than for no-sidecar usage. If freeplay preload is too little, the rig may constantly drift back & forth small amounts & require constant small steering efforts. If even just a small amount loose, it may help induce nasty slower speed oscillations, which then you might think that you need a heavy-duty steering dampener, or to turn your dampener on. While that is true, you MUST check the steering head bearings BEFORE playing with dampeners! They are often WRONGLY added in such cases due to instability & steering oscillations between, say 8-30 mph, & then things get egregious from the combined effects of a loose steering bearing and the dampener that was added or turned on. Revisions: © Copyright, 2012, R. Fleischer Last check/edit:
Wednesday, January 17, 2018
Also consider that small car tires will lower your rig, and increase the effective rear wheel drive ratio, which increases RPM for any given road speed.
On some rigs, use of a smaller front tire diameter, compared to the rear tire diameter, can be beneficial for lowering steering forces somewhat, the effect on trail is why it is so.
Use of excessively wide flat tires on the sidecar wheel can lead to poorer handling in several ways, not the least of which is the rolling friction effect, which can make it more difficult to get the rig to handle the same between low and high speeds. There is also the rain-groove effect, accentuated.
It is very difficult for the amateur sidecarist (and plenty of experienced sidecarists!) to know how tire pressures really change feel/handling/etc….and, I've never come up with what I personally consider a good series of explanations that might work for all, or a majority. It is USUALLY easier to specify the sidecar tire pressure; rear tire is less difficult, but the front is problematical. I think most GUESS at pressures, or, just use what 'somebody' recommended. Often that means way high or way low. Handling is affected in several ways by tire pressures. Changing tire pressures can affect other alignments. I wish there were some hard and fast rules. I've certainly thought about it a fair amount.
8. If the tug rear wheel lifts, on turns away from the chair one should pay attention to possibly having a too large average or available suspension movement. Long throw soft comfy REAR suspensions on the tug are NOT good for most sidecarists. The old-fashioned plunger suspensions were really good for sidecaring. Once lift is too much on the rear of the tug, things can get out of control irreversibly, and FAST. A fairly well increased stiffer spring is often a better choice, where rear suspension is concerned ...this tends to lower the possibility of nosing-over the hack.
9. Use normal weight in the sidecar, placed at the normal area, when doing setup and testing. That means that if the normal weight is 40# of tools in the trunk and a 180# person on the seat, and maybe with gasoline in an auxiliary tank and a battery in the trunk, all that needs duplication during testing, with weights, or the real thing .....etc.
10. If the Wheel Lead is increased ...especially if a lot ...not only must reversal be considered, but it is usually a good idea to use less toe-in (within reason). Excessive wheel lead will give pulling to the left, be harder to turn right or left. You can also expect heavy tire wear. The combination of car tires on the tug and considerable wheel lead, will give heavy handling (but very stable too, at least usually). My own K1100LT-EML-EZS rig is like that: heavy handling, follows rain grooves, very stable though. Car tires, 13" lead, 5/16" toe-in. Even so, I may increase the toe-in a bit, in the future.
11. Too little toe-in usually requires too much lean-out ...and front braking is then poorer too.
12. A proper rig seldom requires much lean-out or lean in. Excessive amounts will have many bad effects, including one hardly ever mentioned: a nasty front tire angular wear pattern.
13. Nose up and nose down is seldom discussed. It affects safety, high speed handling, etc. Especially as speed increases, and even more so when turning away from the sidecar at speed. For some rigs, nose up and down has little effect. On some, a bit too much nose up causes excessive sidecar lifting as speed increases.
14. The objective should be not just basic handling, tire life, etc.....BUT SAFETY TOO, including from gasoline storage, rear suspension lift, good braking, handling that does not require excessive or constant muscle power; and, a comfortable and less tiring ride for pilot and passenger.
15. My personal goal is a rig, that, on a flat no-camber road, handles nearly the same, without hardly any left or right pulling, from zero to high freeway speed. This is sometimes hard to achieve, but really is doable on a well-designed and well-aligned rig. Consider just ONE interactive item. At near zero speed (and higher), the lean-out of the tug has a very considerable effect on how straight the rig goes without pressure on the handlebars. The sidecar rig's effect at near zero to rather low speeds has only the tire friction and rather minimal air pressure effects, as far as handlebar pressure goes to maintain straight ahead driving. But, as speed increases, the effects of the sidecar increase, and can be eventually quite high. I have not mentioned toe-in here either. This is why initial guesstimates and then careful alignment changes, one thing at a time, can be so important to obtain a truly good-handling rig.
16. Steering dampener: If excessive, the rig won't try to re-center, and steering effort can be greatly increased, particularly since YOU must re-center the steering, all of which is tiring. The goal should be for zero to minimum steering dampener. Don't use a steering damper at all if you do not need one. Steering dampener design is somewhat tricky. Hydraulic types versus friction disc types (there are REAL differences), stroke lengths, and many other things. The VW damper is often installed wrongly. Steering dampers being added strictly, or mostly for controlling rain grooves is a BAD IDEA. Just because someone is fine with heavy steering (I am, so long as it is tire induced) does not mean others are. Many rigs will require a steering dampener. A lot of information in my tech article on dampers.
17. Sidecar rigs are often rather sensitive to bearing free-play. Bearing freeplay/preload, if adjustable, needs to be set up correctly. This applies to wheel bearings and suspension bearings, which need no special 'sidecar use' adjustments....just have them within specifications. NOTE that BMW specifications for tapered wheel bearings for Airheads give, in MY opinion, a too high maximum specification. See my wheel bearing article. BE SURE your suspension bearings are set up correctly! BE SURE your motor mounts, swing arm, etc., are all PROPERLY tightened. Swing arms must be set to torqued specifications on Airheads. You can get all sorts of false ideas about what is wrong with your rig if things are basically not set correctly.
BE SURE that the steering head bearing is adjusted for somewhat on the tighter side than for a solo, no-sidecar ride. The adjustment should be such that the steering (wheel/tire OFF the ground), will NOT fall all the way, and not hardly much anyway, at the most 1/3 of the way, to one side or the other, if nudged. This is with NO damper fitted or turned on. This is very important.
18. START by setting things for reasonable values. Most rigs use a fixed wheel lead, and that is often not easy to change, so take that into primary consideration initially. Then, change only one thing at a time! One adjustment will OFTEN affect some other adjustment, sometimes considerably. BE PATIENT. A truly wonderful handling rig can take a lot of alignment 'playing'.
19. As we age, and perhaps go to the gym less and lose muscle mass, it is perfectly OK to re-align for less effort, if one understands the over-all effects by the changes. Changes to tire profile, pressure, trail, and a LOT of ETC, affect how one feels at the end of a long day in the saddle.
IF YOU NOW HAVE THE IDEA THAT SIDECAR RIGS HAVE LOTS OF INTER-ACTIVE COMPROMISES, YOU WOULD BE ABSOLUTELY CORRECT!! but .....A really-well designed and aligned rig is a pleasure to drive!
05/24/2004: add link to driving manual and notes for others.
05/26/2004: Add numerous photos and explanations, re-arrange page
06/19/2004: Expand information on tires/tubes
09/04/2004: minor updates.
03/18/2005: Rotate one photo, annotations improved, add notes on rack modification for the snowflake wheel, make a place for a photo to be placed there in the future.
03/19/2005: Modify notations on photos and add photo, enhance some photos for clarity.
05/25/2005: Add section on alignment.
07/21/2005: Alight corrections for clarity.
07/24/2005: Correct Hal Kendall's e-mail address.
08/12/2005: Fengthy note on the steering dampener Heims, etc.
03/16/2006: Final editing; add photos of right lower fairing area, update text.
11/03/2006: Add URL for the free download of the Sidecar Manual.
03/27/2007: Add hyperlink to Hal's manuals.
07/22/2007: Update hyperlinks and manuals information.
01/09/2009: Fix hyperlink.
04/26/2010: Remove bad Ural link.
02/01/2011: Add another link to Hal's books.
05/09/2011: Add more notes on alignment.
10/14/2012: Add QR code, add language button, update Google Ad-Sense code, update Hal Kendall's E address.
10/04/2014: Update, several places. Remove Hal's direct contact information.
10/05/2014: Incorporate a new edited version of what was article SC4, on sidecar frames, which had an internal address of airhdframe.htm. That article has now been deleted.
10/25/2015: Increased clarity of many sections/items.
03/29/2016: Revise meta-codes, layout, improve descriptions, ETC.
11/17/2016: Major revision. Metas, scripts, layout, fonts, HTML simplifications, improve clarity of discussions while at the same time shortening the article. Fix photos for no text wrapping, etc.
11/18/2016: Add addendum section transferred from sidecarURL article.
02/18/2017: Was SC2, now SC2A
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Of special concern for sidecar use is the steering head bearings. The steering head bearings should be set up TIGHTER than for no-sidecar usage. If freeplay preload is too little, the rig may constantly drift back & forth small amounts & require constant small steering efforts. If even just a small amount loose, it may help induce nasty slower speed oscillations, which then you might think that you need a heavy-duty steering dampener, or to turn your dampener on. While that is true, you MUST check the steering head bearings BEFORE playing with dampeners! They are often WRONGLY added in such cases due to instability & steering oscillations between, say 8-30 mph, & then things get egregious from the combined effects of a loose steering bearing and the dampener that was added or turned on. Revisions: © Copyright, 2012, R. Fleischer Last check/edit:
Wednesday, January 17, 2018
© Copyright, 2012, R. Fleischer Last check/edit:
Wednesday, January 17, 2018
Last check/edit: Wednesday, January 17, 2018