# Noisy Rear Derailleur



## mmcycle10 (Oct 7, 2010)

This is an update from my previous thread "Brand New Crank Noise?"...

I don't have a work stand yet, so that is part of the reason why I am having difficulties troubleshooting this issue. But I did decide to hold my rear wheel off the ground and pedal with my hand while holding my head down closer to the source of the noise (I know...what a novel idea).

To bring everyone up to speed, I have a brand new bike with a SRAM Rival group (Force BB30 crank). I originally thought this noise was coming from the crank/BB region, as it sounded that way while on the bike, and it ONLY occurs during pedaling. 

As it turns out, this noise is 100% coming from rear derailleur. It happens as the chain moves through the derailleur and rolls along the two "wheels" that make up the part. It's kind of a clicking noise, and when looking really closely it almost appears that the derailleur is vibrating slightly as the chain passes through. It's brand new and has been adjusted once already, as the low limit was set incorrectly and it wouldn't allow my chain into the 25 cog. It now functions perfectly, but definitely makes this noise as I move the chain while pedaling. Any suggestions?


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## PlatyPius (Feb 1, 2009)

Don't pedal?

Take it back to the shop you bought it from.


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## andulong (Nov 23, 2006)

Does it happen on all cogs? Might want to check the b tension screw, make sure derailleur pulley isn't bumping the cogs.


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## cxwrench (Nov 9, 2004)

hanger alignment? chain lube? small animal in pulley?
seriously, have the best mechanic you can find check the alignment of the derailleur hanger. a bike that shifts well but makes a little noise makes me want to check the hanger. i put the alignment tool on every new frame as well, and i'd say at least 90% of new frames need some adjusting.


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## mmcycle10 (Oct 7, 2010)

> Take it back to the shop you bought it from


Trying to rely less on going into the LBS for everything. Thought this might be a good opportunity to at least try some troubleshooting of my own and actually learn something about my componentry. 



> Does it happen on all cogs?


Yes.



> check the alignment of the derailleur hanger.


I will give this a shot...thanks!


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## andulong (Nov 23, 2006)

mmcycle10 said:


> Yes.


Probably not the b screw adjustment then..normally only an issue in the larger cogs. Good Luck


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## frdfandc (Nov 27, 2007)

mmcycle10 said:


> I will give this a shot...thanks!




If you don't have the Park Tool DAG-1, you won't be giving anything a shot.


My Force setup is a little noisy when in the stand, but I hear nothing when actually riding it.


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## Kerry Irons (Feb 25, 2002)

*Lube?*



mmcycle10 said:


> Trying to rely less on going into the LBS for everything. Thought this might be a good opportunity to at least try some troubleshooting of my own and actually learn something about my componentry.


Agree that you should learn to troubleshoot bike problems on your own. Could it be that the chain needs lubricant? Is it clicking continuously as it goes through the derailleur pulleys? If yes, then that suggests lube. If it clicks only once in a while, it could still be lube, or it could be a stiff link, or even one of the quick-connect links if you have one in the chain. Close observation and a little detective work should see you through this.


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## DCE (Jul 14, 2010)

I had a similar problem with a new DA RD. Turned out the rear cassette was loose.


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## cxwrench (Nov 9, 2004)

DCE said:


> I had a similar problem with a new DA RD. Turned out the rear cassette was loose.


yep, that can happen too. usually people check things on the FRAME, and completely forget about the cassette...good call:thumbsup:


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## Amfoto1 (Feb 16, 2010)

I agree about checking the alignment of the der hanger.... The Park tool costs about $50-60, if you want to do it yourself. It's easy to check, you just have to be careful "tweaking" the hanger on some frames, to not do any damage. (I get a little nervous aligning the hangers on carbon fiber frames, mostly.) Go slow and don't overdo it. As rarely as it's actually needed, it might be more cost effective to remove the derailleur and take the frame to a shop that can do the alignment for you. You'll need a rear wheel in the frame for a shop to check the alignment. 

The other suggestions of things to check are all good, too. 

A few additional ideas... 

If it's a clicking that happens once each time the chain completes a rotation, then I'd suspect a sticking link or that maybe the joining link isn't fully seated or is bent in some way. 

If it's happening more frequently than that, it could still be tight links in the chain but is less likely. If it's clicking once per rotation of the jockey wheels in the RD, then it might be a bad bearing or a damaged tooth on one of the wheels. 

Check that the bolts that hold the jockey wheels in the RD are tight. They usually have blue Locktite on them, for good reason.

Check the jockey wheels by hand for play or movement, and for smooth bearings (bushings in some case) and that they are well lubed.

Sram rear derailleurs are not very tolerant of misadjustment. You might try a little adjustment of the barrel screw, one way or the other. Note how much you move it, so you can put it back if it doesn't work. 

I was having some noise out of the rear derailleur that turned out to be corrosion and/or lack of lubrication inside the cable housings, that made it impossible to maintain accurate adjustment. Replaced the cables and housing with good quality (Dura Ace in this case) and that solved the problem. I think the problem in that case was "too much love". The bike's previous owner (I bought it used) had "regularly washed" the bike. Probably got moisture inside the cable casing and that lead to rapid corrosion. Poor quality cables and housings can cause similar problems. 

Besides those ideas... 

What are you using to lube the chain. I've been using Chain-L and it really quiets things down and helps them run smoothly. I've got Sram 1090R chains on three bikes right now, running nicely through Force, Rival and Shimano 6600 rear derailleurs. Chain-L is sold by someone here on the forum. If you are interested in trying it, Google for their website.


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## solomr2 (Dec 13, 2005)

I second the chain lube suggestion. I've found that more often than not most of the unexplained noises on my bike are related to the chain. I've been using triflow, but I just ordered a bottle of Chain-L after reading about it on this forum. The triflow doesn't seem to last long, so maybe the Chain-L will be better.


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## mmcycle10 (Oct 7, 2010)

Thanks guys! I went for a 60 mile ride on Saturday and things quieted down on this issue quite a bit...not completely gone, but not as loud now and seems to be primarily happening on the larger side of my cassette (or it's just the loudest on that side and much quiter and less noticable than before when down by the 12/13 cogs...). 

Chain lube definitely seems like a reasonable troubleshooting tactic, except for the fact that the drivetrain only has about 100 miles on it. I don't know much about this, but I did read on Sheldon Brown's site that new chain's shouldn't need any lubrication for quite some time as they come from the factory already "treated". Would I be doing my drivetrain a potential disservice by lubing too soon??


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## Amfoto1 (Feb 16, 2010)

mmcycle10 said:


> Thanks guys! I went for a 60 mile ride on Saturday and things quieted down on this issue quite a bit...not completely gone, but not as loud now and seems to be primarily happening on the larger side of my cassette (or it's just the loudest on that side and much quiter and less noticable than before when down by the 12/13 cogs...).
> 
> Chain lube definitely seems like a reasonable troubleshooting tactic, except for the fact that the drivetrain only has about 100 miles on it. I don't know much about this, but I did read on Sheldon Brown's site that new chain's shouldn't need any lubrication for quite some time as they come from the factory already "treated". Would I be doing my drivetrain a potential disservice by lubing too soon??



Well, _there's your problem_!

New chains _are not_ lubed. They have an oily/waxy/greasy rust preventative coating on them. But it's not really an adequate lube for use. 

So, you definitely need to put proper lube onto a new chain. Tri Flow, Chain-L, chain wax.... choose your weapon and get busy. Bet that solves the noise and makes for much nicer shifting.

The only "disservice" of lubing too much or too soon is wasting lube and that you'll probably get a lot of spray off the chain, onto the frame, wheels and everything else. Wipe off the excess well with a paper towel or rag to prevent that. Too little or too long between cleaning and lubing will lead to faster chain, cassette and chainring wear... plus the noises you are hearing and poor shifting.

If you get Chain-L, I recommend taking the bike outside to put it on... The stuff has a strong smell initially! 

There are directions on the website and with the products, but in case you aren't familiar with lubing a chain... 

With the chain reasonably clean, put a drop on each link right at the connecting pin. With Chain-L it's thick, so penetrates into the chain best on a warm day. You can use a hair dryer to warm the chain in advance and/or warm the lube to help it penetrate better, especially in cooler weather. Once you have the entire chain thoroughly lubed, let it sit for 15 minutes or half an hour so the lube can penetrate some more, then go back and use a paper towel or rag and wipe off excess. Chain-L stays on very well in all but the worst weather. I'm not a high mileage rider, and pretty much fair weather only, so only need to re-lube with it a few times a year. Your needs will probably vary, depending upon how many miles you put on and if you are often out in nastier weather. 

If "new drivetrain" also includes new cables and housings, watch for "cable stretch", too. This typically is not actually "stretch" at all, but new housings settling fully into all the mounting points, etc. No matter, the result is the same... Some fine adjustments are often needed the first few hundred miles. It's easy on the rear derailleur, with its barrell adjuster. Front derailleur usually doesn't have an adjuster, unless you have one added inline in the cable.


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## rx-79g (Sep 14, 2010)

*Weird advice in this thread.*

New chains come lubed - it's a very good lube, much like the wax that people used to go to great pains to apply. When in doubt, Sheldon is right. However, it is only good for about 200 miles, tops. So lube your chain.

You can't "re-align" your derailleur hanger on the majority of bikes - aluminum, carbon and titanium hangers will break before they will bend. However, it rarely matters. Most rear derailleurs aren't perfectly square to the frame, and it won't matter that much.


In all likelihood, your indexing adjustment is off from new cable stretch. Modern shift systems are so good that the system will behave fine even if the derailleur isn't lining up on the cog above it perfectly. They will make noise, though. You can check this without cranking the bike - put the rear derailleur in one of the middle cogs and look at how the chain comes off the top jockey pulley and onto the cog. If it isn't nicely aligned, turn the cable tension adjustment barrel in the direction you need the derailleur to go. You can set up 95% of derailleur adjustments without turning the crank by simply looking at how the parts line up.

If not that, then maybe the B-tension, but I doubt it. The Rival derailleur doesn't require that much B-tension to make it over most cassettes.


Some people apparently get insulted when I say this, but please don't: But a mechanic's shop manual. The problem with asking for advice online is that people make all sorts of assumptions about what you understand and have already checked. The manual will lay out the best practices and step you through troubleshooting in a logical manner so the first thing your looking at isn't hanger alignment.

If you need to take it back to the shop (and if you've been screwing around with the wrong adjustments, that's going to get more likely), make sure they show you what the problem was and how they fixed it. That's the best way to learn.


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## Amfoto1 (Feb 16, 2010)

rx-79g said:


> You can't "re-align" your derailleur hanger on the majority of bikes - aluminum, carbon and titanium hangers will break before they will bend. However, it rarely matters. Most rear derailleurs aren't perfectly square to the frame, and it won't matter that much.


Huh? I regularly do hanger realignments on all sorts of frames - steel, alu, CF, Ti. In fact probably 90% are off a little to a lot, brand new and right out of the box. It's the very first thing I check before starting assembly. Haven't broken one yet, but I'm very careful. Many or even most _hangers_ are replaceable and made of aluminum (no matter what the rest of the frame is made of) specifically to allow for alignment. You do have to be careful about the brackets the hanger mounts to... those are often CF, Ti or alu, depending upon the frame materials.

You cannot align "by eye", it's not accurate enough. You have to use a tool for the purpose. The Park Tool is one, and would serve dual purpose well as a weapon, if needed. 

Again, I don't suggest everyone run out and buy this $50-60 tool for several reasons. One is because you only need to use it very rarely.... When building up a new frame or when checking one where it's suspected the hanger might have gotten tweaked out of alignment. Someone with one or even two or three bikes really won't need the tool very often. 

And, even if the price isn't of concern, it's a large tool to lug around or store for very occasional use. Many might be best served just taking the bike to a shop to have the alignment checked and adjusted if needed. It shouldn't cost much, especially if the bike is already stripped down or at least the chain and rear derailleur have been removed. You do need the rear wheel mounted in the frame to do the alignment check. 

Finally, another reason to take the bike to an experienced mechanic for hanger alignment is because it _is_ possible to damage the frame. There's a lot of leverage potential using the tool, and some frames' hanger mounting tabs aren't all that heavy duty. Some precautions must be taken when tweaking the hanger into alignment. 

There _is_ some flexibility in the derailleur, to tolerate slight misalignments or a bit of misadjustment. How much tolerance can vary. For example, if you fiddle with the jockey wheels in Shimano rear derailleurs you will notice a lot of "wobble". That's probably by design, to allow the RD to work well in spite of a bit of misalignment. Other manufacturers might not allow as much. And replacement jockey wheels from third party manufacturers, particularly the popular "ceramic bearing" type, have little play or tolerance. Those often force you to set things up a bit more precisely, both in terms of alignment and adjustment. 

Agreed, a good book on bike wrenching is useful for anyone who wants to try their hand at it and is not familiar with the work. Failing that, the Park Tool website has a pretty thorough library of instructions for a lot of the most common repairs and adjustments. Of course it helps them sell their tools!


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## rx-79g (Sep 14, 2010)

Amfoto1 said:


> There _is_ some flexibility in the derailleur, to tolerate slight misalignments or a bit of misadjustment. How much tolerance can vary. For example, if you fiddle with the jockey wheels in Shimano rear derailleurs you will notice a lot of "wobble".* That's probably by design*, to allow the RD to work well in spite of a bit of misalignment. Other manufacturers might not allow as much. And replacement jockey wheels from third party manufacturers, particularly the popular "ceramic bearing" type, have little play or tolerance. Those often force you to set things up a bit more precisely, both in terms of alignment and adjustment.


The upper pulleys in all the Shimano index derailleurs from day one have built in float so that they self align with the cog, making exact centering unnecessary.

Here's what Park says about cold setting:


> IMPORTANT NOTE: It is possible to cold-set or re-bend only certain frames when correcting alignment problems. Some frame material is either too rigid or too fragile to bend. When a frame is bent for alignment, you must exceed the "yield" point of the material. This is the point were the material will bend and then stay permanently deformed. In some materials, the point at which it will yield is very close to the point where it will simply fail and break. Thin aluminum tubing, as an example, should generally not be bent. Carbon fiber frames, such as the one seen below, will not take a cold-set. This material tends to simply flex, and then at some point, break. If in doubt, check with the frame manufacturer.


You can get away with doing it on removable hangers because they are thin and replaceable. The first time you try to bend an older style solid aluminum hanger will be the last.

I don't have any bikes with removable hangers, but I do realize that they are common on carbon and aluminum bikes. Still, remember that they are attached to a fairly delicate part of the frame that doesn't like torque. You may tear out a mounting bolt instead of bending the hangar. If you have to do it, make sure a hub is clamped in the dropout when bending.


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