[F22Rapture]

Without seeing a video, it looks like you might be seeing a lot of slippage. A CIM(?) geared like that at that kind of voltage seems waaaay too fast, especially using a non-compressable wheel. Faster != better.

I would say start with what has worked for other teams so far. Pneumatic wheels, 1:1 ratio first wheel 1:1.25 ratio second wheel, 10-11 volt range on both. If that yields better results, start tweaking one variable at a time until you find something that works well for you.