Before you do this mod I've heard of countless people having problems swapping the throttle assemble out. Cutting the old grips off is a ridiculous amount of hassle apparently. That's why you don't see many aftermarket items on eBay.
Used the Renthal grips that came with the Fast throttle kit. It's the medium compound and applies a nice feel/grip.
http://shop.alpharacing.com/shop/in...iption=1&keyword=grips&inc_subcat=0&sort=20a&
Enter your email address to join: