Looks similar too a pre war BSA Blue star clutch.

email (option): fuzzyempire@hotmail.com

I cleaned up the back plate hoping to find perhaps a part number:

No such luck.

I don't understand what this bearing would do other than prevent the rear friction part of the chain wheel contacting the back plate. Assembled on the bench with a few balls and pressing the two together the chain wheel slides past the backplate with a bit of drag. Take the balls out and it slides with lots of drag. Isn't that what one wants from a clutch? Its also apparent that if the lift on the pressure plate is too much then the balls can escape the races - the grooves they run in are not that deep.

Murray

email (option): murray [at] littlewoodmansion [dott] com

The 6 spring pressed metal clutch hasn't really stood the test of time. I don't remember having any trouble with them back in the 70s but like me they're pretty worn out now. So I replaced mine with a Triumph one from Kidderminster Motorcycles.