|8spd DuraAce Rear Noise - replace pulleys ?||scopestuff2|
Oct 8, 2003 10:00 AM
|I've been struggling with some chain noise coming from the rear deraillure on an 8spd DuraAce. Everything is adjusted, trim is working and still lots of chain noise.
It appears as though the chain is dragging against the inside of the cage at the top pulley of the rear deraillure. Alignment to the cogs is perfect. I've even gone way over in both directions and the chain still drags on the cage right above the top-most pulley.
Has anyone ever experienced this before ? Is it possible the pulley bearings are shot ? Anyone know if these parts are replaceable ?
I found this item, but not sure if it's the correct part:
Any thoughts/ideas are very much appreciated.
Thank you in advance !
|It's possible the bearing are shot but||Dave Hickey|
Oct 8, 2003 10:22 AM
|Have you taken the pulleys off to clean them? If so, did you put them back in the correct place? The top and bottom pulleys aren't the same. If you've removed them in the past, try swapping the pulleys..|
|It's possible the bearing are shot but||scopestuff2|
Oct 8, 2003 12:19 PM
|No .... I've not taken them off in the past. In fact, cleaning has been done with the deraillure attached. Just clean the chain with a chain-scrubber, clean the deraillure with a citrus solvent using a brush, etc. It looks clean.
I'll try pulling it apart. If the bearings are shot it will probably be pretty noticable.
Thank you for the feedback.
If you have any other thoughts on why the chain would rub the inside of the cage I'm all ears. I'm not looking forward to pulling the deraillure apart.
|It's probable the bearing are shot||JimP|
Oct 8, 2003 12:35 PM
|The upper DA jockey wheel bearings are pretty lame. The ball bearings are double race and less than 1mm in diameter to allow the pulley to "float". This design can allow water to contaminate the bearings. The replacement pulleys (non-DA) have better bearings that should last much longer. The replacement pulleys don't float as much, if at all, which is ok if you keep the RD well adjusted. I have recently removed a pair of Carmichael pulleys with 15k miles that the bearings are only slightly worn. The Carmichael & Bullseye pulleys are aluminum which can create a little more noise than the composite ones like Tacx. I usually take the jockey wheels off every 500 miles or so to inspect, clean, and relube.
When you reassemble the cage, use a drop of blue loctite on the screw threads and just snug the screw, not tighten. This will prevent stripping the threads.