Brief Sidecar Fitting Guide

We are talking about the most common form of sidecar fitting which is a 4 point mounting, so this is 2 at the front and 2 at the back.

Let's assume that the sidecar will bolt onto this hypothetical bike and don't worry about if it's compatible or not for the sake of the fitting guide.

The first job is to fit the mountings onto the bike frame. Do them up tight and then loosen the nuts off.

If it is easy to take the body off the sidecar chassis then take the body off. It makes the job a little easier.

The next job is to sit on the bike and see how much the rear suspension goes down. Then find a way of compressing the rear suspension so that goes down a similar amount without you sitting on it. For this I usually use ratchet straps around the swing arm up to the frame.

In theory you could do the same for the front suspension however it's not that critical and other adjustments may go against this anyway.

The next job is to position the bike upright on the ground in a convenient position so you can place the sidecar next to the bike so you can begin the attachment process. The bike needs to be sitting on its wheels but held in the position that it will be with somebody sitting on it. I've got a jacking system that I put under the bike frame. You need to make sure the bike doesn't fall over so some additional straps would be a good safety measure.

Put the sidecar chassis next to the bike approximately where it's going to go and use a couple of axle stands or similar to get the sidecar chassis level both ways. Spirit level is best but you can do it by eye. The height of the sidecar floor is determined by the sidecar wheel size and vertical positioning.

As a general rule of thumb the sidecar wheel needs to be ahead of the rear wheel of the bike, typically 8 to 12 inches. The further forward the sidecar wheel is the more stable the machine will be, however there are limitations to where you can go with this.

Set the 'tow-in' whilst the sidecar chassis is disconnected. Loosely bolt on the front lower mount and then recheck the tow in. It will still be level because it's on axle stands.

At this point adjust the lean out of the bike, this is adjusted typically two or three degrees leaning away from the sidecar. However you may need to adjust this later anyway depending on how well the outfit rides. Recheck the 'tow in' then bolt the other three 3 mounts on. Tighten all 4 mountings. The sidecar chassis is now mounted in a position where you can road test the outfit.

I usually road test at this point with some weights on a wooden board on the sidecar chassis. With practice you can tell whether its right or not when you've done as little as 25 yards. It should not be pulling to the left or right at steady 30mph.

This is basically what you have to do and it's then a matter of putting the body on then putting the electrics in place and you're done. This information has all come from personal experience from fitting more sidecars to motorcycles than I could ever begin to count and help from my father and comments from my grandfather who was fitting sidecars in the 1930s.

Here's a summary of the steps to fitting a sidecar:

  1. Fit the mountings onto the bike frame and loosen the nuts off.
  2. If possible, take the body off the sidecar chassis.
  3. Compress and clamp the rear suspension so that it goes down a similar amount to when someone is sitting on the bike.
  4. Position the bike upright on the ground and put the sidecar chassis next to the bike in the approximate position.
  5. Use axle stands to get the sidecar chassis level both ways.
  6. Set the 'tow-in' and adjust the lean out of the bike.
  7. Bolt on the other three mounts and tighten all four mountings.
  8. Road test the outfit with some weights on the sidecar chassis to check it's not pulling to the left or right at steady 30mph.
  9. Put the body on and install the electrics.

Remember that this guide is for a 4-point mounting system, and it's important to make sure the sidecar is compatible with your bike before attempting to fit it.

We offer a selection of new sidecars & fittings, please contact us for more details or with any questions which you may have. Call David 07808 572709 or e-mail

David Evans

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