Noise From Derailleur Pulleys
 

I have started to develop a noise during the last few rides. I don't hear well and locating noises drive me nuts finding the source.

It's similar to a freehub click but not as distinct of a "click". I figured out quickly it happens with pedal movement....coast and it's gone. Higher cadence=higher volume. I couldn't get it to make a noise I could hear on the stand. Now, it's louder and whatever it is really started complaining when I was out of the saddle on a hill.

I put it back on the stand. Crankset/BB smooth & tight (200 miles from new), and quiet. I did get the noise with a high crank rpm and could tell it is from the back. It does stop when the crank stops.

As best I can tell it's from a RD pulley, although I can't hear well enough to tell which one it is.

This is a RD-7800 that I got about 150 miles ago. It's scratch free and was as clean as new, but total mileage is unknown. Could the seller have cleaned it enough to wash lubricant out of the pulley bushings? Should I take them apart or can/will a liquid lube find it's way to do any good.....I've got most everything from thin (3n1) to thicker (Chain-L). Or, are they a best replaced consumable piece.

Thanks in advance, Greg.

I'd put a bit of oil on the bushings of the derailleur pulleys. I like Phil Wood oil for this job.

You didn't mention frequency. most of these "out of saddle" clicks are cadence timed, and usually not the RD pulleys which are well insulated from the influence of pedal motion or chain load. The most likely cause (or at least the easiest to confirm or rule out) is the pedal/crank joint. Remove and place pedals, cleaning the faces well and greasing threads and tighten "tight". Or swap for a pair of pedals known to be quiet.

If i isn't the pedal thread, it could be at the BB, or hub which flexes with each spike in chain load. IME, after the pedal threads, one of the more common causes is a broken axle, or axle flex which creaks against the dropout.

One tip I read somewhere (maybe here on BF) is to jam a paper towel in between the rear brake and rim to give more resistance when turning the cranks on the stand. That load might help you tease out the noise better.

I've tried oil and grease inside my derailleur pulleys after a cleaning, and they always make a little chatter when I'm pedalling, so I don't know if the RD is slightly misaligned or it's just their nature to make some noise...

Before going near the pulleys, stop and think about the sound and consider that pulleys turn roughly 4-5 times the speed of the crank. So anything pulley related will be either a very random or frequent repetitive chirp, or click, or more of a steady clatter. And since the pulleys live on the slack lower loop, whatever is wrong with a pulley will be unrelated to pedal load.

Apply Occum's razor, and if the noise comes and goes with pedal load, look for things affected by pedal load, and or the chain tension spikes of pedal motion.

BTW- add to my earlier list of usul suspects, a loose cassette, or lockring not tight enough. Again easy enough to stick in a tool and give the lockring an extra tug.

I pulled the wheel, the lockring was tight--but I got another bit of oomph on it. The pulleys have little sealed bearings in them--nothing to lube but I cleaned them just because. I replaced the pedals, greased and tight. The bottom bracket has no play and is as smooth as it can be. I didn't take the crankset apart to check actual bearings, it's less than a few hundred miles and I don't have enough power to do any damage to a GXP assembly.

The noise, on the stand is definitely from the pulleys and I can feel it in the lower one especially. Like FB described--a steady clatter.

It's too hot. I'll run it down the road in the morning.

You've changed the description of the sound, so that changes the possibilities. If the pulley has vestigial teeth (most do) it will get noisy with wear, because as the diameter shrinks so does the pitch. With the now shortened pitch, the chain creeps during engagement because it can't settle properly. If it were a sprocket it would skip, but not having any load, it simply runs noisy.

You described it better than I did!!!

I don't know what "vestigial teeth" are to say what these have.

I assume that they are what came on the RD. They both say Dura Ace and the top pulley is different from the bottom in the center bearing area. I don't know the total milage on the RD. The noise has started within fifty miles of cleaning factory lube off a new chain (dry rag) and relubing. Never had any problems before, I figure that's just a coincidence.

Most RD pulleys these days aren't round discs, but sort of like sprockets with very short, or mostly cut off teeth (vestigial). so as they wear, the rollers no longer mesh smoothly. and you start getting the clattering. This is a long slow process, and takes quite a bit of time. It doesn't happen suddenly, so I suspect that it may be related to the removal of the factory lube, since that's when it began.

OTOH, it could be something else like a bent or twisted cage, or a bent hanger that has the chain engaging the pulley at an angle, and having to settle in sideways.

Diagnosing drive train noise is difficult enough with a bike right in front of you, doing it remotely is nearly impossible.

You have to do this methodically, identifying the rhythm and nature of the noise, when it does and doesn't happen, whether the rhythm matches crank, hub, chain or other motion. Also consider any changes that preceded the onset, and what they might have caused.

I replaced the pulleys out of my 105RD (glad that I hadn't listed it for sale yet). The noisy ones appeared to be fine, until they were side by side the 105 pulleys. They were worn just a bit but the newer pulleys eliminated the noise. All's quiet again.

I don't see why the 105 parts won't work for a week until the new ones arrive.

Tacx nylon is quieter than harder plastics and the Metal aluminum ones ..

Thanks!!!

Glad you found the cause! I'm wondering now if my bikes would quiet down a little with newer pulleys -- there's a part of me that feels I should use up parts until they stop working well, though. ;)

The Tacx pulleys came in this afternoon. No problems. Just pick the bushings per drawings matching derailleur and it's all the the same as factory pulleys.

Smooth and quiet.

OTH......the paper towel in the brakes works great to load the driveline great. But not so much for locating noises. The noise from the paper towel drowned out the noise I was trying to locate!!

D'oh! :lol: