Originally Posted by SlamMan
Are they not all differentials? The "regular" diff is a ball differential.
No. Ok gather round people...
A "diff" is a differential, turn one wheel by hand the other wheel turns the other way.
A "spool" is a solid front axle, turn one wheel and the other turns with it. There is no diff functionality
A "one way" allows each wheel can spin freely forwards only. it is kinda like a spool when the power is on, because both wheels turn at the same rate, but off power can turn at different rates.
diff = brakes
spool = brakes
oneway = no brakes (or very little at best)
as for what to use where? that's personal choice, and alot of it is up to your driving style, a few pointers... if you are running a fast motor, you will need brakes, go for a diff or a spool, if you are running a slow motor and dont use brakes much anyway go for a oneway. the main reason is that with a diff on a high grip surface, and a low power motor (silver can etc) you will shave off lots of speed going round corners, this is especially noticeable when going from full speed down the stright into a sweeper, and there is someone right behind you. its like they get a huge burst of power. really its just you slowing down, even though you are still on full throttle...
hope this is useful though