What overdrive are you running?

[Cuiken]

Just swapped the gears to try out the ~12% overdrive feature (up from stock ~6%).

The good:
1. Wow, it really pulls itself round corners now.
2. I was skeptical but it really does seem to help with trickly steps etc.

The bad:
1. It's comedically 'hoppy' in reverse
2. You can hear the tyres protesting if you're on a smooth (concrete) surface

I quite like the extra manouvarability but I'm a wee bit nervous about the constant strain on the drivetrain if not running on a loose surface.

What have other people settled on and has anyone had any issues with the 12% overdrive?

Ta.

[Phildirt]

Following along...was curious about this myself. I have the RTR version and have not swapped to the bigger OD yet. My mind can't wrap around the front spinning faster yet but that's coming from 1:1 and all of the no no's involved with that. Plus I do a little trailing so didn't want to adversely affect all of the other things my truck does. I have noticed the hopping in reverse and just figured it was the RTR ESC doing it's RTR thing lol.

[Cuiken]

Bump for any comments on this? Particularely keen to hear if anyone has had any reliability issues with the 12%

Ta.

[svt923]

12% overdrive is pretty mild with people regularly running 20-25% and comp builds pushing into the 40-50% range. Front overdrive has been commonly used for a long time in scale trucks and problems have been extremely rare.

[Phildirt]

Most annoying thing I've seen is if you are using it as a trail rig at walking speed or faster it won't go in a straight line no matter what your steering trim is set to, at least mine won't. If you stop and crawl on things plenty it's an easy tradeoff. It doesn't bug me a ton, just tap the steering but I rarely go flat out on a trail anyways, just whenever I see mud

[smog]

12% , no trouble whatsoever. I much prefer the performance of the overdriven rig.

[AC49]

My brother swaped up to a front Overdrive setup for a while on his SCX10.2, I can't tell you what the % was but I don't believe it was that drastic as it still drove straight, didn't dart and I think he was getting something like 1 exta turn on the front wheels for every 6 of the rear. So what's that like.. 16% I think.

Anyways, it worked quite well on crawls however on trail runs and urban walks it developed some serious heat compared to stock gearing. Battery life dropped by nearly 50% and he went from a nice 150-170 degrees on the motor to 220.
After changing the OD gears out for stock, temps dropped and battery life returned.

So if you plan on doing some long walks with it then I would suggest keeping a close eye on your battery life and motor heat.

If you are like me and do a mix of crawling and walking then my suggestion is to stick with 1:1
Ideally you have a second axel ready to go that you can swap out quickly and then you have the ideal setup for whichever type of crawling you are doing that day.

[CamoColton]

Originally Posted by Phildirt

Most annoying thing I've seen is if you are using it as a trail rig at walking speed or faster it won't go in a straight line no matter what your steering trim is set to, at least mine won't. If you stop and crawl on things plenty it's an easy tradeoff. It doesn't bug me a ton, just tap the steering but I rarely go flat out on a trail anyways, just whenever I see mud

I noticed this too. I thought it was just me, or "poor" geometry (not enough caster). But yeah, mine definitely tracked better with the milder OD gear set. If I remember correctly, mine tracks to the right more often, I'm guessing from the left front toeing inward under power from any play stacking up across the links.



I think I'll be leaving my Trailrunnner with the milder OD, just because I plan on using that truck for more trail, and less hard crawler use. I'm curious though if the very symmetrical layout of the IFS would experience less torque steer than the solid axle trucks.