Lbxpdx

My first derailleur cleaning. Do I lube or grease and do I need any under the dust caps or just on the center roller?

Iride01 

You'll get all sorts of viewpoints on this. No matter which you choose, it'll work. What's closer to you right now without having to move, oil or grease? Use that one.

Koyote

Wow. I don't think I have ever dismantled those. Am I supposed to do this?

CargoDane

Ha, ha! Only if you want to clean them for gunk and grit.

Lbxpdx

I bought a winter project bike and I soaked the derailleur and it seemed clean. Then I pulled the pulley gear or whatever it is called and they were filled with mud. It probably wouldn’t hurt and it’s really easy.

Koyote

Hmm. I’m wondering if those bushings are designed to be used without lubricant. I’m thinking that grease in there might attract dirt.

sdmc530

Lube it! Grease will attract dirt and grime IMO...I lube mine when I do a full disassembly every winter off season.

easyupbug 

Like Iride01 said, clean and re-grease the bushings, the seals are to keep dirt out. Some guys use a dry lube like Triflow. Some guys just drop a dab of oil on the jockey wheel when they oil their chain. All good, depends a lot on how you do your preventive maintenance.

Moe Zhoost

Grease is thick oil. Oil is thin grease. Both are lubes. Neither attract dirt but both will capture dirt that touches them. If this occurs, the dirt migrates to the bearing surface more quickly with the thin oils, but not much at all through grease. For the best combination of reducing friction is to use a thin oil on the bearing surfaces and then pack some grease under the dust seals.

frogman

What he said

canklecat

Suntour recommended running sintered bearing pulleys dry. I tried it that way but the drivetrain felt draggy. I tried every lube I had -- oils with and without PTFE, grease -- no help. I finally switched to Tacx sealed bearing pulleys. Best $15 I've spent on older rear derailleurs that were originally equipped with sintered bearings. No need to replace the later Shimano Centeron pulleys.

Litespud

I pull the pulleys maybe once a year, clean up all the parts and apply a thin layer of grease to the bushings. AFAIK, they bushing-pulley interface is the only one that moves. The end plates are clamped against the end of the bushings and the rims of the end plates slot into the circular grooves on the pulleys but don’t touch. However, the rotating pulleys will contact the inside faces of the end plates at some point, so maybe a light greasing on the inside faces of the end plates. I don’t know where the washers in your pic go - my 10sp Campag pulleys don’t have such washers. If they’re some form of seal, then maybe a light greasing, as they look like they might contact the end plates
TLDR - lightly grease everything

jadocs

I use a little bit of silicone spray

79pmooney

You have 3 options and they all work (with one reservation). Assemble with grease. Oil, either as you assemble or after. Assemble dry. Reservation: keep them reasonably clean. Oil if needed. If wanted, disemmble and repeat when gunked enough.

If tried all three aproaches over the years. I think oil or grease slows the development of wobble. They do attract dust which accelerates wear. I've never noticed enough difference in pulley life to say you have to do one approach or another. Pulleys don't last forever. The chain is going to kill the teeth no matter how nicely you treat the pivots.

The real question - how pristne does your bike have to be, I cannot answer that one.

Ben

Litespud

I agree - with even the most basic maintenance, the pulley teeth will likely wear out long before the bushings do

CargoDane

Because your years of experience tells you so? Oh, wait.

Sealed bearings have seals. If you force grease into them, you might carry grit in with it. And if you take it apart to regrease them, you may very well destroy the seals so they are no longer sealed.

There is also the fact that bearing races and to a larger extent, bushings which can be made from a variety of materials, and some react to some types of lubricant (grease or liquid - that is: Some swell up with petroleum products or whatever), so it's not really that clear cut as you make it out to be.

I swap out my sealed bearings if they suddenly dry up. Because if they do, the seals are not working.

Anyway, a derailleur pulley is not sealed.

CargoDane

"The same member"? Did you copy/paste that? No, that was rhetorical.
I did it because it was relevant to how much your advice could be trusted. I have left you alone for a while, but that nugget of naive "advice" needed to be countered.

"" Indeed.

cyccommute 

If you don’t clean them before adding grease, you might carry grit into them. But simply wiping the surface will remove most any grit that might cause problems. I don’t agree that the seals are that delicate. If you aren’t ham handed about lifting a seal, it can be done many times.

There are some materials that might swell in the presence of lubricants but none of the materials you’ll find in derailer jockey wheels are adversely affected by lubricants or solvents. The o-rings may swell but not many jockey wheels have o-rings like Lbxpdx‘s in my experience.

Many are. Both OEM and aftermarket. Both SRAM and Shimano use sealed cartridge bearings in their jockey pulleys on their higher end products.

To Lbxpdx‘s original question, I’d use grease over low viscosity oil. The oil flows and the grease doesn’t. The grease would stay put in the bushing while oil will flow out where it can attract dirt.

CargoDane

The seal forms a labyrinth of sorts to keep dust/water out. Wiping them on the outside will remove some grit, obviously.

Fair enough if you feel that way.



I know. Cubewheels mentioned "Bearings/Bushings".


No, most doesn't even have that, but some sort of hard plastic (HDPE or UHDPE or some such - "self-lubricating".

Okay, I stand corrected. Most aren't though, and the one in the OP isn't either.

cyccommute 

To be clear, I don’t add or refresh grease in a cartridge bearing by prying up the seal. Cartridge bearings are replaceable and cheap. I ride them until they seize and then replace the bearing. I’ve only had a couple of bearings seize in years of using them. But, if you are particularly cheap, gently prying up the seal doesn’t damage it.

Bearings and bushings aren’t going to be made of any material that can have an adverse reaction to grease and oil. Both are usually metal...although ceramics can be used as well...and are meant to be used in the presence of at at least a little bit of lubrication.

Nylon. Polyethylene is too soft and has too low a melting point.

CargoDane

Pretty sure I have seen UHMWPE used as bushings. But if nylon that is worse in another direction: It absorbs even water.

cyccommute 

D’oh! Upon further research, the plastic jockey wheels are Delrin. Different from either nylon or polyethylene.

GamblerGORD53

All the deraileurs I've used had the top pulley fixed in by a rivet. So you're stuck doing both ways.
I sprayed ski lube in mine occasionally. I've taken the one apart too. I solved the problem by getting rid of my defaileurs. LOL

grizzly59

Light synth grease is about the best there.

CargoDane

Although I know of Delrin, and I gather you're right that it was Delrin all along, I was interested how it would compare to UHWMPE, so I found this:

https://readingplastic.com/uhmw-vs-delrin/

I thought you too might find it interesting.