I have a proline proformance transmission on my rusty for about a month now and all I do is bash and bash hard mainly because there is only 1 track any where near me and it a about 50 miles away. also no bmx tracks nothing. so construction sites parks and the street any I beat the you know what our of my rusty, and the proline ( 86 / 19 or 23 and 9.6v venom 5000mah) and it's been stellar is strong fast and quiet. For what it's worth that's my 2 cents.