[wheeledgoat]

yeah, i know a guy that removed his optidrive, kept reverse, and loves it. all you gotta do is make sure you don't switch into reverse while moving - there's no safety catch to prevent damage at that point, but shifting into and out of reverse becomes instantaneous without the opti-drive.

i remember reading in some Traxxas literature that they alluded to the opti-drive having something to do with shifting, but that's not the case so far as I can tell... it just prevents reverse shifting while moving. like Dafni said, the shifting is all mechanical with springs and tension inside the tranny.