Originally Posted by
sweeks
I'm hoping to get a response from Dan Burkhart and others with experience with the Shimano Alfine-11 hub. Mine has started making a disturbing (and embarrassing) noise.
The hub has 10,500 miles on it and has had the oil changed every 600-700 miles since it was new.
The shift cable adjustment has always been on the mark.
The oil was changed recently (on schedule) but after the noise started. No metal bits were noticed or anything else unusual. The amount of oil recovered has always been close to 25 ml.
The hub shifts normally (ie, flawlessly) at all times.
The noise is a rapid sequence of low-frequency "knocking" sounds when the hub is under load. It happens with pressure on either pedal. It sounds like the chain is running over a frame element or other solid part of the bike. It isn't. I can feel the vibration through the pedals. The noise is present is all the gears and sounds the same, as long as the hub is under load. The bike coasts silently and smoothly, and there is no lateral play in the wheel. I have never opened the hub.
I've ruled out the pedals and their couplers. The bottom bracket is relatively new, and the cranks spin smoothly with the chain off (not tested under load though). The chain is not worn out, and the chainring and rear cog are relatively un-worn. The chainring bolts are tight. The chain is not rubbing on the cassette joint.
The weird thing is that the noise got markedly worse after I removed the wheel to repair a flat... this makes me hopeful that the noise is not from the hub, but as I've said the chain path is free of interferences and I've tried to account for all other possible sources.
I am prepared to remove the hub and open it to inspect for worn parts. I have a serviceable Nexus 8 red-band hub and shifter that I can put on the bike, but obviously I'd rather not.
It seems unlikely (to me) that there could be something inside the hub that's so wrong that this noise is produced without interfering with the shifting.
Any suggestions as to what I could try to sort this out will be most appreciated.
Steve
Well, it sounds like you have at least considered most of the possible external sources if not completely ruled them out.
I really don’t have any thoughts on what could be an internal cause of your symptoms.
Do you have another bike you can swap the wheel into? I’m thinking it could still be an external issue such as cranks, bottom bracket, pedals, or even saddle or seat post. Those types of sounds are elusive and often very difficult to isolate.
Or you can swap in the Nexus wheel and see if the issue persists.