Axial gears (overdrive/underdrive)

[natskiboy]

I have always used overdrive front snd underdrive rear on my scalers. I want to know what is an optimum setup for a ultra 4 rig.

I was told to underdrive both front and rear. Currently i have overdrive front and rear.

Im using a Tekin RSX and ROC412 3300kv combo.

Can someone help. Thanks

[MountainStorm]

Originally Posted by natskiboy

I have always used overdrive front snd underdrive rear on my scalers. I want to know what is an optimum setup for a ultra 4 rig.

I was told to underdrive both front and rear. Currently i have overdrive front and rear.

Im using a Tekin RSX and ROC412 3300kv combo.

Can someone help. Thanks

Under drive has the best mesh so adjust your gearing at the transmission with the spur and pinion to get the wheel speed you want because the under drive axles will really slow you down.

I've managed to keep the HD spiral cut 13/38 sets alive in my 11 pound U4 rig but I am careful. If I went balls out all the time they would be toast after a run or two. I will be going to under drives and a larger pinion soon.

To give you an idea of what the "experts" think: Super Shafty does not sell the over drive gear sets and does not recommend using them. They have the least amount of mesh and will strip out the soonest.

[meatmonkey]

I currently run underdrive gears front and rear in my Wraith. They are the strongest of the 3 options and help reduce TT, making them the natural choice for abusive go-fast U4 fun.

IMO running uneven gears at higher speeds makes for sketchy handling, but others don't seem to mind as much.

[natskiboy]

Forgot to mention im running a Dinky split skid setup. Supershafty beefed up internals. Not sure how many tooth the spur is though (have to check)

[SimpsonC1]

I run 38/13 in the front & 43/13 in the rear of my rigs. It is great for crawling & I haven't had any problems at high speed. I run MMpro/Roc412

[winnerone23]

I run HD stock front and UD rear on my Sexo/wraith drive train. I use it for an all around rig.. Trailing, crawling, C3, go fast basher, rock racing.. 3500kv HD on 4s.. 30mph..
I like the effects of the off set gearing at all levels..

My yeti ran UD F/R.. 3300kv HD on 4s at 30mph.. The gears are rock solid..

So I guess it's just preference and what your choice is.

[k7zpj]

This thread answers most of the questions that you can think of about over/under with the Axial HD gears including where to use the different combinations.

Overdriving the Front Axle?

The right combo really depends on the rig, how it is setup, how you drive and what problem/capability you are trying to address.

To find the optimal answer and really understand how it works, you need to buy the gears to be able to experiment and observe performance with the different ratios.

[new2rocks]

X2 to what k7 says. I tried OD front and UD rear in my Wraith (ROC 412 3100 on 3S) and found the front end darty at higher speeds on surfaces with any traction. I switched to HD stock ratio in front with UD in the rear and like it much better. It climbs better than matched ratios and almost as well as OD/UD without the sketchy high speed handling. If I were going more for speed than crawling/climbing, I'd probably go UD/UD for the reasons others have mentioned. The best way to figure out what will work best for you is to try out a couple of combinations on your rig in the same place(s) and see what you like.