2.01 Suspension
From Sidecarwiki
All modern bikes have suspension, as do all modern sidecars. It isn't just a luxury, it is a necessity. But the standard suspension for a solo bike isn't usually well suited to sidecar use. (I had a Dneipr MT-9 which handled sweet as a nut with the standard suspension, but that was an exception). How to improve it will vary greatly among all the possible combinations of bike, sidecar, roads and riders, and I'm sure there will be lots of suggestions from users around the world, but the aim is to find the best compromise between handling, comfort and maintenance.
The rear suspension of the bike usually remains standard, but may be stiffened either with the standard adjustments, or by changing the spring and damper fluid.
My Guzzi outfit has a pair of Fournales shock absorbers running 10 Bar pressure.
My Kawasaki outfit uses the standard rear shock with the pre-load and damping increased using the standard adjustments
The front suspension of the bike gets a lot of discussion going. Standard forks, leading links, Earls forks, and many others are seen and discussed.
My Guzzi outfit has standard front forks. I added a spacer (increased the pre-load) to regain the height that the weight of the sidecar took.
My Kawasaki outfit has a custom leading link front end with a pair of Koni shock absorbers. This reduces the trail and hence the effort needed to steer the outfit, and stops the front end from diving under brakes.
The sidecar suspension varies greatly depending on the manufacturer. The four types I have seen are a leading link and standard shock absorber, a trailing link and standard shock absorber, a trailing link on a steel torsion bar and a trailing link with a rubber block.
When well adjusted, the sidecar suspension minimises the amount that the bike tilts sideways when the sidecar wheel goes over a bump, and the amount that the bike leans onto or away from the sidecar when cornering.
If the suspension is too soft at any wheel, then the outfit will sag there when cornering. In severe cases it will wallow, making the outfit hard to handle in corners.
If the suspension is too hard, the bike will be thrown about. Mounts for fairings or panniers may crack or break from the extra vibration on rough roads. The front or rear wheel of the bike may skip or slide when braking or cornering.
The usual rule, that the suspension should settle about 1/3 of its travel under normal load, seems to work. Stiffer suspension can make the handling more stable, at the expense of a rough ride. Softer suspension is more comfortable, but cornering feels funny. There is plenty of scope for experiment and individual taste.
-- Pogo. 21 Jan 2008
