Just allow me to caution you about putting any motor on any Wally World $85 Huffy type cheap bike, especially for your kid to ride with a motor.
It's not a matter of IF the bike will fail, it's HOW SOON, what fails, and when it happens.
It is usually the back wheel first too, no fun when you are cruising full speed.
Maybe just surprise him with a new solid bike a few month before you motorize it?[/QUOTE]
My 2010 Huffy has more than 1,000 miles hauling MY 200lb carcass hither and yon without failure... but then, it's outfitted with the HOWARD HUB MOUNT instead of the ragwort mount and sports several remarkably HOWARD modifications. I have tested the frame and wheels as well as done the structural numbers on these bad boys... I trust them. The eariler ones, 2009 and prior, are at the low end of the learning curve.
I am a qualified gunsmith- that covers welding, machinework, blacksmithing, metulargy both ferrouse and non, structural and mechanical engineering as well as an assortment of arcane skills that would have little bearing in this endeavour. I have a turret lath, upright mill, pony gas rig, Lancaster longbed forge with two Peter Wright Anvils and full setup along with the regular assortment of DIY goodies. When I design something, I take note of the works of John Moses Browning and Paul Mauser for inspiration... while he was alive, I had the privilage of correspondance with 'Mad Bill' Ruger... I was one of the few who would call him that to his face. He offered me employment... silly me, I turned him down due to his ornery nature. Live and learn.
Point is, I am accustom to the idea of designing something to handle strong force.
And again, my experiance leads me to trust the Cranbrick.
the Old Sgt.