Clunking hub

[anon4]

My partners bike has developed a clunk in the rear hub motor that happens once per revolution. It happens powered or unpowered so it's definitely mechanical. It's a deep clunk and can be felt through the frame, worsens with peddling, have ruled out spokes and brakes already, I'm guessing either freewheel or something in the hub. Any ideas

 

[Nealh]

Remove the chain and rotate freewheel to rule out issues, check tightness of wheel nuts and AR washers in drop outs.
Put up on a workshop stand if you have one and rotate the hub either powered or not to try and pin point the clunk better, if it is internal then could be a broken down bearing or clutch/ casing drive gear may need greasing . What ever if it is , if pin pointed as internal noise hub will need opening.

 

[anon4]

Forgot to mention the noise only happens with a rider on it, everything appears to spin freely otherwise

 

[Nealh]

Check the cranks are tight, the only time added rider weight might affect a hub AFAICS would be with axle rotation and play in hub axle or a knackered bearing.

 

[Nealh]

Forgot to mention the noise only happens with a rider on it, everything appears to spin freely otherwise

Oil or grease the riders joints.

 

[anon4]

Check the cranks are tight, the only time added rider weight might affect a hub AFAICS would be with axle rotation and play in hub axle or a knackered bearing.

Just tightened the bottom bracket and cranks, plus it happens without peddling just that makes it worse. Looks like a teardown of the hub is needed. The rider is a bit worn but I don't think it's that

 

[Sturmey]

I had a similar problem twice in the past, once with an ordinary 21 speed bike and once with an eight speed ebike (even with power turned off). In both cases it sounded as if the hub was been hit with a small hammer (a deep tapping sound). In both cases, it was noticeable that there was play in the freewheel bearing and in both cases, I dismantled the freewheel and removed one of the packing (shim) washers, instead of replacing freewheel. Anyhow, in your case, I would (with the bike turned off) check the freewheel by grabbing gear cluster and see if there is much side to side rocking/play. Even the smallest amount can cause the freewheel body to knock against the hub side at its bearing.

 

[Nealh]

My partners bike has developed a clunk in the rear hub motor that happens once per revolution. It happens powered or unpowered so it's definitely mechanical. It's a deep clunk and can be felt through the frame, worsens with peddling, have ruled out spokes and brakes already, I'm guessing either freewheel or something in the hub. Any ideas

Which hub do you have ?

If it is a bearing the freewheel will have one maybe two. The hub has one on the brake side and a larger central one, if opened you can roate them by finger to feel if there is any issue other then a smooth rotation.

 

[anon4]

Which hub do you have ?

If it is a bearing the freewheel will have one maybe two. The hub has one on the brake side and a larger central one, if opened you can roate them by finger to feel if there is any issue other then a smooth rotation.

It's unbranded as far as I can tell, came in this kit we bought to replace the original wheel as spokes kept breaking https://www.ebay.co.uk/itm/36V-250W-Rear-Wheel-Electric-Bicycle-Motor-Conversion-Kit-E-Bike-Cycling-Hub-26/113440267463?hash=item1a69911cc7:g:pDgAAOSwNXpb-GbU

 

[Nealh]

Screwed face plate should be easy to open.