Overdrive and underdrive

[dmcchaser]

Hi,
I see a lot of people are running overdrive gears in the front and underdrive in the back of their AX10s.
What is the benefit of that? I'm guessing it helps keep the crawler from flipping over backward on steep climbs.
Does it affect the turning radius?
Can just one axle's ratio be changed, or do they both need to be changed for it to work properly?
I assume there's a gear set from Axial that includes the parts to do this.

 

[JeremyH]

Personally, I run the overdrive gears in the front and stock in the back of my Axial. Yes, the front wheels turn a bit faster and drag the rears along (barely noticable). This does help reduce torque twist and will help on vertical climbs when you need the front pulling a bit harder than the rear is pushing.

No, you dont need both for it to work. You can run both, or only the front overdrive, or only the rear underdrive....

 

[Stormin2u]

Typically only one axle is modified either under drive (rear) or over drive (front). The fact that your front wheels in either situation are turning faster than the rear gives the front a slight wheel speed advantage with less lift caused by the rear wheels better climbing. It also help increase turning it's a must have mod IMO.

 

[dmcchaser]

Cool. I'll add that to my "to do" list.

 

[dmcchaser]

I was doing some shopping around and I realized I don't know what's in my crawler now. What's the stock gear ratio in an AX10 diff?

[edit] just found out the stock ring and pinion are a 13/38 ratio.