racing them downhill reminds me of the gravity bikes that were made back in, I think the 80's? where you took the crank/pedals off a bmx bike and raced downhill. truthfully I can't see why that couldn't be done now. if a person really needed a larger strider bike, just take off the drive train, then put it back when your ready. or for racing just pick up any old flea market bike and again, take off the drive train. got a couple myself (pretty much never play with them though)