It’s a frame up
In which Mick Payne takes the blame for something he didn’t do...
Last time I tried to cast a little light on the construction of sidecar bodies and what I took at face value as a Steib body for sale wasn’t.* Thanks to John Hind for pointing out that it is actually a Garrard GP built in Bletchley, probably even more desirable. Whatever your body is, however, it usually needs a chassis to make a sidecar and, like bodies, these have evolved over time.
Back in the early days of the beast, motorcycles had no rear suspension so the chair followed suit; the body might be suspended on coil or leaf springs if the passenger was lucky. With rear suspension came similar springing for the sidecar. My own BSA A10 outfit had a sprung wheel and the Meteor body pivoted at the nose and was supported by two cee-springs at the rear. The BSA also had mounts for sidecar attachment on the frame, as did many of its contemporaries. No subframes here, as is the case with many modern classics.
Different means of providing springing at the chassis were applied. Most mimicked motorcycle suspension with some form of swinging arm and a spring/damper unit, although this was not universal. Watsonian used a limited form of suspension in the ‘wobble wheel’ although this would be improved with a swinging arm and spring/ damper unit. As bodies advanced, then the famous Silk and Super Silk chassis were developed with a drum brake as an optional extra. The Watsonian frames were of a wraparound design and are still used on the company’s classic models today. There was, however, a new kid on the block. Squire started manufacture in 1974 and used a similar frame format, some having a roll bar incorporated into the design. One feature in which the Squire departed from the norm was by using rubber in torsion units as a readily available alternative. The medium also has the advantage of not needing a separate shock absorber; this lived on in the Watsonian Stratford until recently.
Another use of torsion type suspension is the Hedingham chassis, another perimeter type. From the first Unit design a transverse torsion bar was utilised, at first without a damper, although many later versions had one fitted. Sourcing the bars was relatively easy as the system was fairly common in the automotive world and could be machined to suit individual applications. If this type of suspension is good enough for the Jaguar E-Type it should be good enough for a sidecar. One popular sidecar within the classic movement is the Czech Velorex. These have a tubular platform chassis with conventional swinging arm suspension and are often found attached to Jawas. But, owing to their lightweight origins,
there is one point to be aware of; older models might not be suitable for fitting to heavier bikes. The early models had a wheel spindle of just 15mm while later and current frames use a 20mm spindle. That translates as a cross-section of 177sq mm compared with 314 for the larger diameter, a big difference. Fortunately, a conversion kit is available to update any earlier models.
The Indian-built sidecars currently available also use swinging arm suspension controlled with a spring/damper unit. These are readily available and make a good alternative to the Velorex, although there are still question marks over quality. I’m not sure this is deserved as they must do plenty of miles in their home country on rough roads. Sadly, anything built outside of Europe, the US or Japan does seem to be treated with suspicion. Time will tell and it will be interesting to see what the new Chinese Chang Jiang outfits are like when they reach the UK. Will they end the discrimination?
*I can’t let Mr Payne shoulder the blame for the mislabelling of a Garrard GP body as a Steib in OBM434. That was entirely my error and I can only thank Mick for his chivalry in attempting to take the blame – and for not shouting at me! Blue