Originally posted by Boomer
Ummm, we're talking about nitro cars here. Nitro cars use al. chassis'.
Nitro cars have a lot of oil and dirt and sometimes rocks get in them because we have to run outside (although I've heard of indoor tracks. . .) just like the off-road guys. Most off-road tracks around here don't have much bigger rocks in them than you would find around the edges of an on-road track (like Rev). . . I pick up little rocks all the time in my spur and pinion gears - I used to pick them up in the belts of my GT-4.
The conditions of an 1/8th buggy are harder than we get (off-road is harder on drivetrains which is why 1/10th uses slippers and we don't), but the point remains - we use a shaft just like the hardest class on drive-trains do. If a shaft won't hold up, why do they use TWO of them? (and they can seal a drive-train. so why don't they do it?)
Shaft drive is durable in an environment where there are a lot of debris. I have ruined around 2 pulleys and no belts in 2 years of onroad asphalt racing, so I guess my track is pretty clean comparitively. So I really have no drivetrain preference either way on my tracks.
There are two things I dont like about shaft drive however. Firstly the drivetrain is very rigid making on power wall impacts dangerous. Secondly the design of a ring and pinion drivetrain inheriently is self destructive. Ie the pinion is always trying to push itself away from the crown gear putting a lot of sideload on the gearbox housings and the bearings.
This being said it can be made to work nicely, but the above design elements need to be considered.