Rear Derailleur Noise

[JeffWarner]

Here is one that I haven’t run into before. Checked all the common issues. Since Google’ing didn’t offer anything else useful, I’ll take any suggestions/opinions.

I have a Dura Ace 9000 Mechanical group with 10K miles. A few rides back, I started to get an increase in drive drain noise. I thought it was the front derailleur out of trim and rubbing, but after putting it in the stand; it’s the rear mech. Specifically, it’s the jockey wheels; the chain is not riding smoothly on them .. almost looks/sounds like the pitch of the chain is off or a tight link.

Things checked:
- Confirmed it’s not the hub/cassette by removing it from the bike and running a chain keeper.
- Chain is good. Clean/lubed, no stretch and no tight links.
- Pulled both jockey wheels and cleaned them. They spin smooth, bottom one has the correct orientation. - No noticeable wear on the teeth and pitch measures about the same as the jockey wheels I have on older 9 & 10 speed stuff.
- It’s not the B-limit screw or shift wire tension, no issues shifting in the stand or under pedal load.
- It’s an old-school-attached-to-the-bike derailleur hanger, no screws to get loose. The hanger is a ¼” slab of Titanium, so I can’t see it getting bent without the frame suffering a serious and noticeable impact
- Derailleur has no side to side wobble and doesn’t look bent. Bike hasn’t been laid down or wrecked. Chain alignment between the jockey wheels and cassette look good visually.

While it looks like the jockey wheels are the culprit, I can’t see if they are not visually worn (pitch widened) how they would cause an issue. The internet searching says most of the time, the issue is a bent derailleur. While it’s possible, I don’t suspect it … no signs of impact and shifting is spot on. Before I haul it off to the LBS or give in and buy a new derailleur, anything else to check?



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[zmudshark]

I'd check derailleur alignment.

[sales guy]

Here is one that I haven’t run into before. Checked all the common issues. Since Google’ing didn’t offer anything else useful, I’ll take any suggestions/opinions.

I have a Dura Ace 9000 Mechanical group with 10K miles. A few rides back, I started to get an increase in drive drain noise. I thought it was the front derailleur out of trim and rubbing, but after putting it in the stand; it’s the rear mech. Specifically, it’s the jockey wheels; the chain is not riding smoothly on them .. almost looks/sounds like the pitch of the chain is off or a tight link.

Things checked:
- Confirmed it’s not the hub/cassette by removing it from the bike and running a chain keeper.
- Chain is good. Clean/lubed, no stretch and no tight links.
- Pulled both jockey wheels and cleaned them. They spin smooth, bottom one has the correct orientation. - No noticeable wear on the teeth and pitch measures about the same as the jockey wheels I have on older 9 & 10 speed stuff.
- It’s not the B-limit screw or shift wire tension, no issues shifting in the stand or under pedal load.
- It’s an old-school-attached-to-the-bike derailleur hanger, no screws to get loose. The hanger is a ¼” slab of Titanium, so I can’t see it getting bent without the frame suffering a serious and noticeable impact
- Derailleur has no side to side wobble and doesn’t look bent. Bike hasn’t been laid down or wrecked. Chain alignment between the jockey wheels and cassette look good visually.

While it looks like the jockey wheels are the culprit, I can’t see if they are not visually worn (pitch widened) how they would cause an issue. The internet searching says most of the time, the issue is a bent derailleur. While it’s possible, I don’t suspect it … no signs of impact and shifting is spot on. Before I haul it off to the LBS or give in and buy a new derailleur, anything else to check?



Sent from my iPhone using Tapatalk


I would make sure on this. It's super easy to get these backwards or in the wrong position. I've seen them backwards AND the upper on the lower and vice versa.

Usually that is the cause of pulley noise.

If they are correct, then check the hanger. It could be tweaked just enough that you can't see it with a naked eye. Alloy hangers are super soft and designed to bend/break so not to destroy the frame. They are normally the cause of pretty much all derailleur noise or shifting issues.

[oldpotatoe]

Der hanger alignment. Even 'slabs of titanium' der hangers get bent. Also make sure rear wheel all the way into dropouts, to make cogset in proper, flat plane in relation to rear der.

[eddief]

How many miles on the chain?

I have used a Park chain checker and it indicated my chain was fine. And in the end, a new chain fixed noise / shifting issues.