Q128C motor not spinning freely

[kurtster]

My shiny new Q128C motor, built in a 20-inch wheel, arrived a few days ago from BMS Battery, but still waiting for the battery which I ordered from another vendor. In the meantime, after placing the wheel in the dropouts, I noticed that it doesn't spin freely by hand, in fact there's a LOT of resistance.

Is there a break-in period for this motor, or do I need to add grease to the gears? This is my first hub motor, so any advice appreciated.

 

[motomech]

Did you bolt on a brake disc?
Perhaps one or more of the mounting screws is too long and pegging against the stator.
Other wise, dismount the motor and try and turn it by hand.

You ordered the motor from BMS Battery and the battery from someone else
I've thought for years that the batteries from BMS Battery were the best things they sold.

 

[Ykick]

It should turn a little harder in one direction than the other but still turn fairly easily using mild input. There should be nothing needing grease or attention (clutch) for a while. Is this rear or front motor?

As moto suggest, brake rotor bolts?

 

[kurtster]

That was it, chaps. Many thanks. I used the rotor bolts from the original wheel, instead of those supplied by BMS, as they seemed to be the same length, but on closer inspection they're slightly longer. Crossing my fingers I didn't cause any lasting damage.

Anyway, now the only other wrinkle to work out is the contact between the hub and the brake calliper unit, which I had to disconnect in order to allow the axle to seat properly. Looks like my only option is to find a replacement unit with a narrower profile.

 

[motomech]

That's the downside of the Q128, it's rather wide.
I've been able the create clearance for set-ups with a flat file, but the interferance was not great.
You don't need to replace the motor, you get a larger disc w/ an adaptor to move the caliper out.
I'm guessing you didn't have time to do any research here before starting this build.
It's time to do some searches.

 

[kurtster]

Oh, I should've been clear that by "unit" I meant the caliper unit, not the motor. Should be a trivial matter as this particular caliper is rather wide.

All in all I'm very pleased with the motor from a stealth standpoint. It's smaller than expected, and the rotor combined with a 42T sprocket I have lying around somewhere should help make it even less noticeable. From a cosmetic standpoint though I would've preferred a one-cross pattern to the radial one used by BMS.