alot of nitro cars have 2 speed gearboxes.

basicaly its a centrificle clutch that engages another "gear set" as it disengages the first.


looking at the savage SS instructions [link=http://www.hpiracing.com/index2.htm]http://www.hpiracing.com/index2.htm[/link] (page 18-20) it looks like you have 3 gears on a shaft. one drives the shaft. the next is on a one way bearing (first gear) and the other a slipper clutch.

when the slipper clutch engages second gear the previous gear freewheels on the one way. i have a savage but never had to take apart the gearbox yet.