I saw the Mtroniks one at Starluck RC.
http://www.starluckrc.com/catalog/pr...roducts_id=146
They even have a combo with a Feigao 380c 7T motor.
http://www.starluckrc.com/catalog/pr...roducts_id=158
But the bike takes a 540 size motor (I beleive the mounting hole dia. is about 6mm smaller on a 380 size motor). I have read that some people have used the Novak 5800ss combo but I was looking for a little bit more power.