Help! Clunking noise inside the hub motor.

[Lezallib]

Good morning!

So I received an ebike conversion kit a few days ago, the battery will be here in about 10 days.
Its a 48V 1000W gearless hub motor(rear) with a 7-speed freewheel.
I've been seeing how everything will fit together and what additional parts/equipment I will need.

Heres the meat of the matter. During all this, I noticed a concerning clunking noize what I believe is inside the hub motor.
It happens once per revolution. I am quite certain that it is not the freewheel because the noise still happens even if the freewheel is stationary, but doesn't happen when the wheel is spinning backwards and is engaging the power train.

Any help, tips, or suggestions would be amazing.

 

[vfr400]

There are no moving parts inside the motor. The stator is stationary and fixed to the axle. The rotor is attached to the hub and it's turned directly by the magnetism of the stator. The hub turns on the wheel bearings like any hub. I can understand a tapping of clicking noise from something like a loose magnet on the rotor, but not clunking. Can you video or record the sound?

 

[Lezallib]

The sound is quite deep and sounds like is coming from the outer part of the motor. I am at work currently but I can record it when I get home.

 

[Nealh]

It's a DD drive so no freewheel at all inside, you will find that out when you try and ride it without power .

 

[Lezallib]

@Nealh Yeh I am a bit concerned about how bad it keeps its momentum when I spin it up whilst my bike is upside down. Haven't test ridden it because of the clunking sound. eek indeed

 

[harrys]

I'm told the DD magnet drag isn't so bad when you're riding, and I have test ridden some 500W DD motors bike a few years ago and they coasted OK. Maybe the controllers on those bikes kept a little current in the windings. I've read that a tiny bit of throttle lets you pedal a 1000W motor nice. Ah, I'll never know. I don't want a DD.

As to the problem at hand, you probably do have a loose magnet. MAke a video for proof and have the seller make it right.

 

[Sturmey]

I had 3 different freewheels making a hammering 'clunking' noise in the last few years. In all cases, a sideways movement can be felt by reaching down onto the freewheel cluster and the wear is evident with a sideways rock.Indeed, in one case (DNP), the freewheel was new so it was not that there was wear but the freewheel was not properly 'shimmed'. It many cases it can be corrected by opening the freewheel (left hand thread) and removing one of the packing shim washers, although this may be too much bother for many. I suppose you could unhook or remove the chain and try 'ghost' pedaling to completely eliminate the freewheel from your inquiry.

 

[barbe]

So lezallib I want to hear your "clunking" sound! My motor too makes a Strange sound! And more than just a sound….I feel Something vibrating just when I pull away!

 

[MkFred]

So lezallib I want to hear your "clunking" sound! My motor too makes a Strange sound! And more than just a sound….I feel Something vibrating just when I pull away!

 

[MkFred]

I'm in the unusual position of having two Swytch battery packs - an older, larger one which includes odometer and speedometer for a 700 wheel which I bought second hand recently and a modern one for a Brompton.

I initially had to replace the Quick Connector on the handlebars after which the system worked well for a short time, but then the hub motor started making a clunking noise and the power output was intermittent. At the same time the odometer and speedometer would malfunction. The situation would improve slightly by using the smaller power pack for the Brompton.

This is nothing to do with the freewheel cassette on the back wheel and there is no obvious play in the power hub on the front wheel.

I'd be grateful for any inspiration as to how to carry matters forward.

 

[Nealh]

One suspects a wiring issue with the new connector.
Explain clunking a bit more.