RE: Robinson Racing Spur and clutch bell problem.
If that's the case, you need to move your flywheel back towards the engine more. You can see if you can find a shorter flywheel collet, or maybe you could file yours down about 1mm or so. I had to do this when I installed a new Ofna 17t bell, it was rubbing my spur as well. Also, I shimmed my clutch bell as close as possible to my flywheel to give more room.