Nexus 8spd noise when back-pedalling

shed-dweller
shed-dweller Posts: 123
edited May 2012 in Workshop
Hi guys,
I have a few-month-old Charge Tap with a Shimano Nexus 8 speed hub.

A few weeks in it began to make a scraping sound when back-pedalling only in gears 5 and above (the only gears I ever use). Obviously I don't actually do that much back-pedalling, but it is still rather annoying! LBS is completely nonplussed.

There is nothing obstructing the wheel or sprocket, and nothing the chain visibly rubs on when moving.
The chain tension is fine - altering this has no impact on the noise, and there is no corrosion or rust on the chain.
The cones are adjusted correctly, although they were a bit tight initially.
The bottom bracket is completely smooth.
I am confident that the gear adjustment is correct, as I have tweaked it since buying to accommodate for cable stretch, and the little yellow indicators line up nicely.

The other thing to mention is that when setting off it seems to slip into a lower gear for 1/4 of a revolution, before settling into the correct gear. This is completely smooth; there are no unhealthy noises from the hub when this happens.

Anyone have any idea at all what might be causing this?

Cheers,

Mike

Comments

  • MichaelW
    MichaelW Posts: 2,164
    The noise is a common complaint but is apparently normal.

    My Alfine had the odd clicky moment but since I started oil dipping the mechanism is has been smooth and silent.