A video of one 4200 with the new track motor kit. It's running here up to about 2/3 of full speed. Possible limited speed, in % of full, can be set on most radios. Pretty good torque from those motors, one need a very strong grip to stall them by griping the tracks with one hand) Planning to have some new kits ready for sale in April,
https://youtu.be/60gSjtnwJog