Hey Mike
question : what made you decided to use the gear diff?
well we all started running them last outdoor season. at the time i was sponsored by Atomic/Spec-R and running XRays. They came out w/ a gear diff at the time so I said I'd give it a try -- it was free
. running a gear diff is very similar to running a loose ball diff ... but if you do that in any class other than 17.5 blinky you'll need to rebuild your ball diff very often. when i started running a gear diff it took my 'pushy' XRay T3 and made it rotate, especially through 180s, where it would usually push. and when you jumped on the power the car would just hook-up.. no slipping, just lot of acceleration.
also -- i don't know if everyone remembers or not.. but the Worlds occurred last summer and the Spec-R gear diffs were "very" popular because of the win from Marc R.