Originally Posted by
Snowsurfer
Mtn bike (front suspension only) aluminum frame, add torque arms, even steel frame drop outs will fail.
Mtn bikes usually have wider rims for bigger tires like Schwalbe BA's or Maxxis Hookworms.
They have front suspension which is good.
If you want higher speeds, usually, they have mounts for disc's (e.g. large rotor 8" disc brakes)
On a mountain bike with an aluminum suspension fork you don't want to put a hub motor on the front wheel. Do the install on the rear wheel. The drop outs are cast and easily susceptible to failure without notice--torque arms won't help you.