Self-aligning rear main

[dickie65]

The idea of a twin track self aligning rear main bearing was to allow the crank to whip and not tip onto the ends of the rollers, the bearing is the same dimensions as a standard roller bearing so the flywheel bolts up as normal. In my case it was fitted to an 1 1/2" Allen Crank so less of a problem with whip. I think the theory was explained in the 750 Companion. The Twin track self aligning race was easier to find a than the standard rear main in the late 70s early 80s.
I do not think this bearing would cause crank failure any more than the standard set up although it would change the harmonics.

Happy Christmas