This motor in a mtb ?
 

Would this motor be enough to push a fullsize mtb bike up to 30-40mph ?
And how mutch would i need to gear down ?


http://www.hobbyking.com/hobbyking/s...100cc_eq_.html

Would be nice if there was an actual description of the motor in question.

Wow fancy pants. You wanting to build a middrive setup. I can't help you, but I sure would like to see you building this one up.

Monster Mike should build these middrive setups for bikes. Slap on a big Castle motor or Astro w/Castle esc and call it Monster Drive.

might be worth asking here http://endless-sphere.com/forums/

it claims to be 20+ horsepower, based on that, yes it would work.

By the time that is geared down enough to limit speeds to a reasonable level (~15:1 @ 48v), the torque will be enough to rip the back end apart (even with torque arms) and twist your spokes into pretzels. If you can draw 250A from 48v, geared roughly for 40mph, that would be 176.09ft-lbs of torque at the axle.

Besides, that motor has a no-load current of 13A? Seems a bit high (inefficient) to me even for that size motor.

I would just get a hub motor. Less mechanical things to fab, cheaper, simpler, and cleaner looking.

[EDIT] Actually, one of the comments for that motor said the no-load current at 44v was 22A. Wow, that's bad. Almost 1,000w wasted power.