Type of thread on 2 speed pinions

Thanks guys thats a big help. Looks like I might have to use Mike's gears to get the ratio I'm after. The serpent range goes from 15-17 on first and 18-20 on second (not much of a gearing window!) The only problem with Mike's adapter for my situation is it's a tad short. I need about 25mm of shaft before the inside edge of the second gear pinion. Have a look at the picture in post #25 on this page http://www.rc-monster.com/forum/show...?t=9298&page=2and you will see what I mean. The cardboard cylinder represents where the motor can will be positioned.

[jhautz]

Its hard to tell from the picture, but couldnt you just move the motor mount closer to the spur gears? If you can help it you dont really want to have the gears hanging out that far anyway, it puts alot of extra stress on the front motor bearing.