[karavshin]

Hi there.

I have a Dahon MU XL urban commuter bike. I've put perhaps 250 miles on it and really like it. I especially like the Nexus 8 hub: no deraillers, totally clean shifts, shifting while pedaling, shifting while sitting at a stop light.

Anyway, today I did a few tweaks to my bike (pedals, lights, etc). One other thing I did was to change the angle that the brake levers were mounted on the handle bars. The retailer had them too parallel to the ground, so I wanted to rotate them down about 35-degrees. To do so, I also had to loosen the shift lever set (Shimano SL-8s20). All I did was loosen the clamp screw, rotate, and re-tighten. Everything apparently went fine.

But what I now notice is that when I am in the low gears 1-3, and pedal hard from a dead stop, there is a slipping/popping/jumping noise from the hub. It's as if the gears are improperly engaged in the hub, and giving them load, pops them into a different space. For reference I'm 77kg and about 1.8m. It never did this in the past.

I checked the cabling to make sure everything is properly seated (it is). Checked that the cable was kinked or pulled funny or feeding weird (doesn't seem to be). I've made sure the two yellow lines are perfectly aligned during 4th gear by using the adjustment dial on the shift lever set. Regardless, the popping/slipping continues to happen.

This is really annoying me. I loved how bulletproof this hub was, but now it seems to be unhappy and unresponsive to the known adjustments. What should I do ?

Thanks

 

[w00dy]

There is a chance you are experiencing poor shifting due to cable stretch. It just happened to coincide with you adjusting your controls. I suspect a quick adjustment would set you straight. If you bought it new, your shop should do this for next to nothing.

 

[DavidMakalaster]

It's out of adjustment. It's between gears. If you aren't 100% sure you can adjust it bring it to someone who can. My best friend had one on his city bike and had the same thing happen to it. He ignored it and in 2 days his hub was toast. Whatever you do don't ride it till it's fixed.

 

[Shimano Support]

It sounds to me like you know how to adjust your shifting. It's super simple on Nexus stuff, just line up the yellow marks in fourth gear. Something that may be causing a problem is excessive friction between the cable and housing. The new angle of the shifter may have put a tigher bend in the housing causing this extra friction. This may be keeping the cassette joint unit (the thing that turns on the hub as you shift) from returning all the way when you shift to an easier gear. This may be happening only in some gears because the return spring loses a little power as it gets toward the lower gears.

If this is the case the noise will not occur if you shift all the way down to one and then back up to two. In this case you would be using cable tension instead of spring tension to get you into gear. If you do this little test and it works you probably just need to shorten the housing a bit and then it will work like new. If not, there is a two year warranty on Nexus hubs and your local shop can just warranty the internal assembly so that you don't have to rebuild a wheel.