scraping noise 9C

[Paul T]

Hi all, I have just fitted a 2kw 9C front hub to my Basman cruiser. Its a big pretty heavy bike being all steal but a sweet ride. Anyway there's a scraping noise from the hub motor when just coasting, its quite loud. If you lift the front and spin the hub wheel there's the noise and it doesn't spin freely, there's drag, which I guess is making that noise. Its brand new will this go away and free up with use or is there a problem? It seems to pull really well but would it not be better if it spun freely or at least more freely than it does. Its not rubbing on the forks anywhere I checked.
Thanks

 

[Paul T]

It was just the mudguard stay rubbing on the tyre, how embarrassing

 

[dogman dan]

I was thinking the corner of the hub near the axle was just touching the fork. Very rarely, a zip tie securing the wiring inside the motor can scrape.

That resistance is called cogging, and it's normal. If you want to pedal without using the motor, I recommend still using just a tiny tickle of the throttle to eliminate that cogging.

Not easy to hold the throttle below 100w, but once you get the hang of it, it makes limping home on a low battery better.

 

[itchynackers]

Can you spin it freely by hand? If not, then you need a spacer washer in there so the hub motor doesn't rub on the frame.

 

[dogman dan]

Yep, for others who may be reading this, that's the fix for a cover that still just touches the frame and rubs. It might need a thin washer between the inner shoulder of the axle, and the inner side of the dropout.