Technical Pages

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Setting up a Sidecar


S
ome basic principles of sidecar rigging should be understood prior to attempting to learn to handle a sidecar rig. Even the best of drivers will have a tough time of it if his beloved chair is improperly bolted on.

The following information is general in nature due to the many variables which exist between different sidecar and motorcycle combinations. The measurements indicated are to be used as starting points from which finer adjustments can subsequently be made. This data pertains to the American method of attachment wherein the sidecar is attached to the right-hand side of the motorcycle.




Attachment points indicated on four basic frames. X markes indicate alternate attachment points.

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Toe-IN

Toe-in refers to the slight inward set of the sidecar wheel in relation to the wheels of the motorcycle. All sidecars should be rigged with the amount of tow-in prescribed by the manufacturer. The purpose of toeing the sidecar wheel inward is to offset a slight "crabbing" tendency of the motorcycle's rear wheel, keeping tire wear to a minimum. In some cases, improper toe-in (particularly in conjunction with improper lean-out) can contribute to handling difficulties; noticeably a tendency of the rig to pull to the right or left. Toe-in angle is approximately 1/2 to 3/4 of an inch, measured by a straight edge laid edge to wheel as per Diagram.
C = Toe-in less than at D by 1/2 to 3/4 inch.
Measure to the centerline of the motorcycle wheel rims.

Wheel Location (wheel offset)

The amount of wheel offset is another measurement ordinarily specified by individual manufacturers. For best performance under most conditions (most motorcycles, driver weights, passenger weights, road conditions, etc.), the axle line of the sidecar wheel should be positioned approximately 8 to 14 in. forward of the axle line of the motorcycle's rear wheel (Diagram B). This is the standard which is followed by the majority of sidecar builders. There are exceptions, however, such as the Harley-Davidson rig which is set up with the sidecar wheel even with the motorcycle's rear wheel.


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Vertical Lean

In most cases the bike should lean very slightly away from the sidecar when the combination is unladen (see diagram E). "Very slightly" is defined as being 1/16 to 1/8 inch in 24 inches as measured with a 24 inch carpenter's square aligned with the motorcycle's rear tire centerline or sidewall. With a rider astride the motorcycle and the rear shocks compressed, 1/8 to 1/4 inch of the lean-out is a good starting point.

Literally pages could be written about driving a sidecar unit. Notice the word driving as opposed to riding. Unless this key word is understood at the beginning, sidecar touring can be tricky.

Perhaps the thing to keep uppermost in mind when you first swing into the saddle of an outfit is that the rig must be steered when cornering. The solo motorcycle is leaned into corners and steering is accomplished largely by the shifting of body weight. Not so the sidecar. It does not lean, and getting it around corners is almost strictly a matter of pulling and pushing on the handlebars. Since steering forces while turning with a sidecar are considerably larger, wider handlebars will give more leverage!

A novice should approach his initial sidecar drive with a passenger in the sidecar. There's literally a world of difference in driving an outfit laden and unladen. Straight line driving is the easiest. Motorcycles that have steering dampers are very good since the damper helps control an odd although perfectly normal tendency for the motorcycle to wag its head back and forth at slow speeds. A firm grip on the bars neutralizes this as well.

Front end shimmy is just one of the reactions that have to be accounted for in sidecar driving.

Cornering is where first-timers get into trouble. The left hand bends are great. In fact, an unwary neophyte can get himself into a heap of trouble taking a left hander too fast because when turning left, centrifugal force comes into play and nails the sidecar to the asphalt. This is assuming, of course, that the sidecar is mounted on the right hand side of the motorcycle as is normal practice in the U.S.

The right hand corner is a whole new ball game. Centrifugal force, your instant friend on the left handers, becomes you foe turning right. It tries to lift up the sidecar and you have to counter with some body english and a slower speed.

At anything above a crawling pace, the right hand corner can most easily be negotiated by leaning slightly into the corner, applying some front brake and rolling on the throttle simultaneously. It sounds awkward and is initially, but this cornering drill allows the motorcycle to pivot around on the sidecar wheel with a minimum tendency for it to lift.

Another important consideration is to always remember that you have some extra width to jockey around. Give curbs, cars and other objects in and around your patch a suitably wide berth.

All these hints should be considered even more if the sidecar is empty. With no passenger, the outfit is lighter and right hand turns should be made with extra caution.

Practice is the key to developing into an accomplished sidecar pilot. Temper that practice with a liberal dose of caution and common sense and soon you'll be flinging your outfit through the corners like a veteran.

Sidecar maintenance, simply, is good motorcycle maintenance. The sidecar itself requires a minimum of service. Periodically check the sidecar wheel's brake (if it has one) and tighten the spokes if it has a wire wheel. An occasional wheel bearing repack is also called for. Air pressure in the sidecar tire is generally nearly the same pressure as in the motorcycle rear tire.

The body demands no more than a Saturday afternoon wash and wax and a vacuuming of the interior. Sidecars are quite agreeable creatures and need a minimum of care.

However, special attention must be paid to the motorcycle pulling the sidecar. Most important, keep an eye on chain adjustment and spoke tension of the rear wheel. The bike is working under a load at all times and key systems like brakes, clutch, tires and the like are consequently under more strain than they would be solo.

Periodically check the swinging arm pivot to make sure nuts and bolts are tight. The rear shocks come in for a good deal of use and most sidecar pilots either replace the stock units with a stronger specialty brand or move the stock units to their stiffest position. See: suspension.

After Several weeks of practice, you'll probably notice two things: One, sidecar driving is becoming almost second nature to you and two, people in cars and on the street are usually very friendly, with smiles and waves the norm.

In fact, that may be one of the sidecar's biggest pluses. After all, when was the last time someone smiles and waved at you when you were riding solo?

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