There aren't any good throttles for performance, but that should change soon. Many mods have been tried, we are close to have one offered in the sales section IMO. I use an half grip, for it is the one that is most convenient for mountain riding.
Make it fool-proof, and I will make a better fool.
Norco A-Line, 50+ Mph dirt bike and winter commuter... sold
Specialized Demo 8 performance dirt bikehttp://img715.imageshack.us/img715/5824/dsc03417ae.jpg
Santa Cruz Heckler, lightweight road racer
Santacruz V-10, performance dirt bike
Work in progress:
Trek Session 10