Over-size piston in 94.46mm for all R 100 models up to September 1980.

These forged pistons are approx. 240 g lighter than the originals and their compression ratio is 9.5:1.
This increases the power and also the torque.
Piston kit is including piston rings, pins and clips.

You will not need new cylinders, just let yours bore and hone.