Nice work 93firebird. Yeah metal spur and pinion will be a little noisy. Are you running 6s with 2200 kv? What center diff?
Are you sure that your system isn't cogging at the startup? It would explain the rough noise.
Sry guys, have to admit that my projects haven't gone any further. Still looking some extra time. Since now weather has cleared up in here cold cold Finland my other hobby has started to taking my little time
There's my DH bicycle