Cutting down the fork tubes.
Cutting/reshaping a CB77 swingarm.
Swingarm with new torque arm anchor welded in place.
into the headstock and then assembled in the yokes. The forks were then placed into the yokes followed by the front wheel, to complete the front-end sub-assembly. The next job was to make a swingarm. My initial thoughts were to make one from scratch, but looking at the CB77 swingarm I could see that is was similar in many ways and could easily be modified. The main difference was that the pivot points were designed to fit on the outside of the CB77 spine frame so I cut the swingarm in half, reshaped the halves, then cut a
Swingarm parts.
Cardboard template and pressed-up side-plates.
portion out of the cross brace to reduce the width at the pivot end. The two halves were welded back together with a new one-piece bearing pivot tube and the plates were then welded on the top and bottom for added strength. The shock mounting points will need to be modified as well but I can do that later while making the frame so that I can position the shocks at the correct angle. I trial fitted the rear wheel in the swingarm, reduced the length of the wheel’s spindle and machined new spacers to centralise
the wheel, I then positioned the brake plate, attached the torque arm and welded a new anchor point onto the underside of the swinging arm. With this complete I now had the front and rear sub-assemblies ready to make the main frame. The frame for my RC374 would be an open type frame with the engine suspended underneath as a stressed member, but due to the design of the FZR engine it was not possible to stress the cylinder head as part of the frame like on the original RC174. I would have to www.classicmechanics.com / 73