Exposed gears in off road

[Saito2]

Not Tamiya specific (although the original Holiday Buggy counts), what's to opinion of exposed pinion and spur gears on off road vehicles? I've seen this on the Redcat Ground Pounder and possibly the HPI Savage Flux. It seems odd to me. Wouldn't that be a wear issue or worse if a pebble managed to lodge in there? Maybe I'm too used to most Tamiya's nicely sealed up drive trains.

[Gruntfuggly]

I've always thought that it works both ways - when it's not covered, anything that does go in has a good chance of going out again. Unless you've got a totally sealed box, there's a danger of something small getting in and staying in...

[speedy_w_beans]

In a lot of 1/8 scale buggies, truggies, and monster trucks, the pinion gears and spur gears are hardened steel.  Not a big problem for a little bit of dirt/dust, honestly.  Guys run their nitro buggies and e-buggies at the local dirt track all the time, and the center diff spur and pinion gear are completely exposed.

[WillyChang]

Stones does get stuck in gears... pick them out with sharp tool.

But 1/8 gears also much chunkier like 32dp or mod10, can survive better.

Gears don't live forever.

[Jonathon Gillham]

My Lazer has the exposed spur and pinion setup in the middle. I haven't had a problem with anything getting in there, the body fits snugly over the chassis and is velcroed so its just really dust that gets in. Its also just a plastic 48p spur with hardened aluminium pinion, so nothing special. 

From what I've seen its only the belt drive cars (Losi 22-4) that have sealed drivetrains.

Funnily enough I have more problems on carpet, that stuff gets everywhere

[IoWBasher]

I've an FTX Hooligan rally car that like all the other variants of the chassis doesn't have a fully sealed transmission, whilst it's fine on dirt and grass if I use it on gravel I know I'll destroy the spur gear and pinion.

Therefore unless it's a fully sealed transmission I avoid gravel where possible.

[markbt73]

Never had a issue with the nitro trucks in the late 90s, and they all had exposed clutch-bell and spur gears. And the spurs were usually plastic. Scalers/crawlers often have exposed spur gears as well.

But then, I have also made rally cars out of both an HPI RS4 Pro and an Xray T1, both with exposed spurs, belt drives, and ball diffs, and ran them in loose sand and dirt, and nothing ever failed...