5

I have a Nexus 7 speed hub with 19t cog and a triple chainring.

Experiment: Using a rear derailleur to take up chain tension; the hub shifts fine in all gears and the the triple shifts fine. It all works well in that respect.

Issue: I have resistance in the hub while back pedaling that leads to slackening in the top run of the chain.

Question: Is this resistance normal on internal geared hubs or should it spin while back pedaling as freely as a cassette based hub?

Cheers Rod.

1
  • What's the approximate mileage on the hub? Has it ever been serviced ?
    – Criggie
    Jun 18, 2022 at 1:53

1 Answer 1

1

You may have some resistance, but it shouldn't be so high that the top of the chain is going slack. The chain should spin freely, as long as you are not spinning it backwards as fast as you can (really only possible if it's up in a repair stand). I would check a couple of things:

  1. As mentioned by Criggie, I would evaluate the need for maintenance. If you have the same resistance while turning the hub sprocket by hand, or feel grinding or binding, the issue is with the hub internals.
  2. Since you are using a derailleur, make sure that the derailleur is clean, and all of the jockey wheels are turning freely. If one of the jockey wheels turns (but with more resistance), it won't be able to keep up with the rest of the drivetrain while pedaling backwards.
  3. On the derailleur, also check that the main pivot moves freely, and the derailleur can snap back when you shift from high to low gears in the front. The pivot may stick if it is rusted inside, or had been damaged and cannot rotate freely.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.