jb wrote:Alfine 11 owners might find my following findings interesting especially regarding some faults that have been reported further back in the thread.
The other day I was climbing a steep hill in bottom gear, when I got to the top and tried to change down it went into the wrong gear or would not change at all. I dismounted and started looking and found the selector arm to be stiff on part of its travel. After loosening the wheel it became loose again and I tightened it up and carried on. All was well until I hit the next hill and I dropped down to low. It became stiff again and gears were not selected in their proper order.
I decided to strip it down for a look.
All was well until I came across one half of this almost hidden in an alcove:
I looked around but could not find where it had come from and thought it may have broken off the end of the clutch spring which was the same cross section, so against my better judgement rebuilt it thinking it could have been causing the stiffness by getting caught in the mechanism and maybe it had always been there hidden. Not surprisingly down the road at the next hill the same thing happened again (hoping never works)
The only place left to look was the complicated spring mechanism so I rather reluctantly dismantled it and low & behold the other half appeared just inside the fixed sun gear:
So now I have the whole hub stripped to its bear bones:
So, what the problem was, & what the problem could be for a lot of failures is this clip breaking which causes the sun gear to be pushed forwards because its helical and there is side thrust. This in turn causes slight binding of the gear change mechanism, however a bit of back peddling can re-seat it & loosen it off again.
I'm a bit disappointed now because this is
a) looking like a weak spot in this hub gear which was up to now proving quite robust
b) The part is almost certainly unobtainable without buying the whole axle mechanism (haven't looked into the cost yet). I am reluctant do do this if this is going to happen in another 5000 miles or the next 1:4 climb
I could attempt to make one but its taking a lot of force and needs to be a very particular shape. There's probably a huge box full of them sat in Shimanos factory and my otherwise undamaged hub gear is grounded without one. This seems to be an Achilles heal of this box and makes it now an uncertainty for long tours, although I could have ridden it for a while as it was.
Hope this helps others with identifying Alfine hub problems.
You're a braver man than me stripping it down as far as that. I presume without a manual of any sort?