Is this normal wear on derailleur pulleys?
 

Is this normal wear on rear derailleur pulley wheels? This from a Deore M590 RD used for 20-30 thousand miles.

I believe the left pulley is the lower one.



https://cimg8.ibsrv.net/gimg/bikefor...50dd58cfea.jpg

Sure, if you don't take care of your stuff that's what happens.

Seen it plenty of times, you're running metal over plastic, eventually they can't help to look like that. Just pick up a nice new pair and be amazed at how the new bearings or bushings make it seem easier to pedal and how noise went down. Not a big deal.

Yes, I've worn a few sets to where the teeth are pointy. Replace them.

Frankly I would have replace those 10,000 miles ago :)

Another vote for not unusual wear especially for a dirt/dirty bike. Replace and enjoy the ride.

Were you looking for manufacture defect and wanting a free replacement?

Just replace them. Its what you do when things get worn. Surprisingly though, I think I've seen some that looked almost like that new back in the vintage days when all sorts of DR tech was going in every direction and experimenting on us.

No - I wasn't sure if i did something wrong. Like not replacing the chain frequently enough or similar.

Replacing the chain more often will quickly out run the cost of replacing the pulley wheels when they need it.

All cogs wear.... and pulley wheels are cogs technically, but they are special, so they get a more special name. At your mileage you should have some other things needing changing if you haven't already.

I have changed the cassette a few times and the crankset has maybe 7-10 thousand miles on it. A road biker fell on me and destroyed my original crank.

They are worn out. Maybe the local bike coop has a RD or the pulleys you could swap in. Congrats on riding your bike enough to wear parts out. Awesome.

I'd suggest you clean & lubricate your pulleys more frequently. Typical non-DuraAce/XTR Shimano pulleys are simple bushings. They run fine when clean and lubricated. They have no real pulling load on them, as they simply act as tensioners. But they quickly get dirty, dry out and get stuff wound around them, fouling them and causing a lot of drag. I've been amazed to see how much friction dry pulley wheels can add to the drivetrain. This wear indicates they had developed a fair amount of friction and that's why they wore so much. I have yet to wear out a set of pulleys to that extreme.

After 20 or 30 thousand miles that's totally normal, even if you were using aluminium jockey wheels it would be normal. I would have replaced them several times in that mileage.

And yes, the left pulley is the lower. The lower one always gets more wear because it takes the chain at an angle unless you always ride in a gear combination that involves a perfectly straight chainline.

How do I lubricate them? Do I put chain lube on the cover or take the RD and pulleys apart and put grease inside?

The replacement pulleys appear to use cartridge bearings.

Thank you. I was curious why one of them had more wear.

Whatever you do, in 20 or 30k miles they will be destroyed anyway. I'd just check that they're clean and spin freely. If they don't i'd try to free the bearings with a bit of oil. If they're just a bushing you can probably disassemble it and clean it. I've mostly had problems with them seizing on MTBs, as they tend to get wet when crossing streams or puddles and water doesn't play nice with the bearings.

Keep in mind that they're plastic and as I've side before, the lower pulley takes the chain at whatever angle the gear combination you're using causes, and also the chain sometimes comes in weird angles due to bumps and irregularities, especially on MTBs. This means that the harder side plates from the chain rub against the teeth of the wheel constantly which causes the wear. Even if you use aluminium sprockets,aluminium is quite soft compared to the chain and doesn't make that much difference.

What can make a difference is keeping them clean, as dust, sand and any type of contamination gets trapped between the pulley and the chain plates and works as an abrasive.

Try to keep them clean and running freely, but I don't lose your mind over it. They're relatively cheap, usually last a long time, and after all, like all parts of the drivetrain, they're a consumable.

Thank you for the guidance.

If it's a sealed bearing pulley just clean it up, then put everything back together. I wouldn't try and take any of the bearing apart.

Removable bushing pulley-
Remove the round metal covers on either side. Q-tips and solvent, push out the bushing and clean whole pulley, teeth, grooves, and bore. Clean inside and out of the bushing. Find some grease, shouldn't feel too thick or crusty. Grease the inside bore of the pulley, outside of the bushing. Put the metal covers back, bolt the pulley assemble back into the derailer. When installed, pulley should spin freely.

I just pulled apart a set of Dura Ace pulleys. I was being careful and all, but I still screwed up and dropped 7 teeny-tiny ball bearings on the shop floor! Total rookie move!

Found all but one! Probably 99% of pulleys have no actual ball (or cartrigde) bearings in them. These are really nice pulleys and deserving of an overhaul. Cleaned with fresh grease? Like buttah! And will roll better than bushing pulleys for a long time.

A 3mm allen wrench removes the pulley bolts so you can fully open them up and clean them. Again, they're basic bushings. But as I said, when they get dry, they can create a lot of friction. Clean off the old gunk, apply light lube like TriFlo and reassemble. LocTite on the bolt threads isn't a bad idea. Pulley bolts tend to fall out at the least opportune times!

In the future, just drip a little oil between the plastic and medal washer on the pulleys and wipe off all the excess. The oil will work its way in and will keep them happy. Overhaul 'em only as frequently as you see fit. 6 months or a year? Watch the football game and clean your pulleys!

If you have actual cartridge bearing pulleys, they can be flushed with solvent and relubricated without too much trouble. At least there are no individual ball bearings to fall out!

By the time my pulleys look like that, the joints on the parallelogram are usually worn out too. I’d just get a new derailer personally.

Couldn't disagree more. IME most derailleurs can go through 2+ sets of pully's before the derailleur is worn.

Imo, replace the pulleys when you replace the cassette. Not very expensive and they do help better gear shifts.

Really glad to hear it! I hope this means derailers have been improving, durability-wise.

To me, it looks like abnormal wear. After 26000 km on the road, mine (sram force 22) are still very similar with the new ones, just the edges are a little bit less firm. And I use to heavily shift, to keep a constant cadence.
I had to change the whole derailleur for a new "middle cage" to accommodate bigger cogs (11-32), otherwise I think the old pulleys would last well above 100.000 km

It is on my all weather commute bike and I also ride it on dirt roads and dirt paths after work and sometimes on weekend.