I wanted to do away with the 16″ rear wheel and discovered the wheels and forks from an ’82 XS400 Seca would bolt right on.
There were just a couple of issues.
- The SR250 has a 520 chain and the XS400 has a 530 chain. The splines on the countershaft sprocket are the same, but the XS400 sprocket has a shoulder. As a quick hack fix, I made the XS400 sprocket fit by grinding off the shoulder.
- The rear brake backing plate on the XS400 is held using a brake arm attached to the swingarm and the SR250’s backing plate is fixed via a slot in its backing plate. I fabricated a bracket for the XS400’s brake arm and had it welded onto the SR250’s swingarm.