heres my story
I decieded to work on my old RC18 and the Mamba 25 wasnt working so I upgraded to a Mamba Micro Pro and run that with a Hyperion yc-22 long can 5000kv motor with a FP 3s 1500 lipo, well it turns out the standard pinion for the 1/18th scale is a 2mm .5 mod and the Hyperion long can has a 2.3mm the short can has the 2mm shaft.......I have found this to be very irratating....