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Question for moderator, Spinningmagnets

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    Question for moderator, Spinningmagnets

    I remember reading a thread you made, about modding the Bafang geared hub motor.

    I just purchased a Bafang geared rear hub motor . It is rated 750 watts at 48 volts . I will be mounting it on a 26' fatbike rim . I weigh around 240 lbs and my ebike weighs around 60 lbs .
    My Lifepo4 battery is 48 volts and can put out 50 amp bursts with a Lyen 12 Fet controller . This means I can go up to 2500 watts output for short bursts { 60 seconds or less} .
    Will this Bafang motor be able to take that type of wattage for short bursts without stripping the 3 nylon gears or burning up the motor ? I already shortened the 3 phase wires to 6 inchs in length
    and went to a much heavier gauge wire for the phase wires, on the outside of the axle { I did not open the hub motor up and replace the wires inside } .

    One nice thing about experimenting with hubmotors is that...if you go a little too far and fry it, you can usually buy an un-spoked hub and simply swap-out the guts very cheaply. It's hard to say if it will work or not, heat is a big issue. It might take 2500W when it is cool, but once you get the plastic gears hot, they cannot take popping wheelies any more (until they cool down)

    if you don't mind drips, you can put a coffee cups worth of ATF in it, which transfers heat from the stator to the aluminum sideplates. Automatic transmission fluid is about $5 a quart, get synthetic.


      Heres the motor I just purchased.

      With the ATF method of cooling, I can expect the ATF fluid to leak out the axle/ bearings ?

      Do you know if any company sells metal gears to replace the nylon gears ?

      I was planning on adding aluminum cooling fins/ heatsink that went around the outside center of the hub motor { between the spokes} since there isn't enough room to put heat sink fins on the side covers. I would use a heat conductive epoxy to fasten the aluminum fins to the motor. Has anyone tried this with good results, instead of ATF fluid that would cause leaking issues ?
      Last edited by rumme; 03-17-2017, 06:15 PM. Reason: new material.