Shaw and Tommy,
The bike i'm working on this with respect to, is my 50/50 stock cylinder E-50. I'm trying to get a 2 shoe to hold up to an absurdly high stall speed so i've been doing some research.
The motor wont be finished until spring, but I'll let you know when i find out how well this works and what it costs. You can actually buy the material from mcmaster-carr, and the material is fairly cheap, so i dont think it will cost much. I'm mostly interested in how well a harder material locks up.