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View Full Version : Help! Derailleur pulley lubrication



OakLeaf
03-23-2008, 11:49 AM
Well I pulled my derailleur apart so I could thoroughly clean my chain, only to find out that I've got ceramic bushings in one of my jockey wheels, and I don't know what kind of lube to use on them.

I wasn't expecting that - I thought both pulleys were sealed bearing and I could just clean around them as they probably don't need re-packing yet. But the whole thing came apart.

I sure would like to reassemble everything so I could go for a ride tomorrow! I don't have any bicycle-specific grease, so Deb or whoever, if you could specify the composition of whatever grease I need to use (moly paste, white lithium, etc.) that maybe I could get from the auto parts store, that would be a huge help! Thank you!

r900
03-23-2008, 01:34 PM
Just checked Barnett's manual and they reccomended light grease. I have used white lithium grease used for engine rebuilding. It is a very light weight grease that doesn't get thick or sticky.Can't think of anything off the top of my head right now that would be similar.

mimitabby
03-23-2008, 02:50 PM
I sure would like to reassemble everything so I could go for a ride tomorrow! I don't have any bicycle-specific grease, so Deb or whoever, if you could specify the composition of whatever grease I need to use (moly paste, white lithium, etc.) that maybe I could get from the auto parts store, that would be a huge help! Thank you!

boy, a stop by your friendly LBS might be in order. they know what to use, they use it all the time. I don't think Deb's been by today or she would have surely answered!

ridebikeme
03-24-2008, 04:09 AM
If you haven't already done this , I would check with your LBS. Having installed ceramic bearings in a number of bikes, I have found that some do use grease and some do NOT! It really depends whether it is a true ceramic bearing.... does it have a ceramic or steel race AND ceramic bearing? Did it have or appeared to have grease on it when :pyou pulled it apart?

Good luck!

KnottedYet
03-24-2008, 06:01 AM
We are so lucky to have DebW and Ridebikeme!

Thanks you guys! :D

DebW
03-24-2008, 06:25 AM
boy, a stop by your friendly LBS might be in order. they know what to use, they use it all the time. I don't think Deb's been by today or she would have surely answered!

I did see the question, but didn't know the answer. I've never used ceramic bearings, and a quick web search turned up conflicting advise. So thanks for the enlightenment, Ridebikeme! After my UBI course this summer, maybe then I will know EVERYTHING??? :rolleyes:

OakLeaf
03-24-2008, 09:36 AM
Thanks all! I wanted to ride this morning before the LBS's opened, is why I didn't go right to them.

For the record, it's the top pulley in an '07 Ultegra derailleur; both the "race" (is that the proper term when it's bushings?) and the inner bushing are ceramic. There didn't seem to have been grease in it; it cleaned up really nice with Simple Green and water and running a damp paper towel through it a couple of times. Just a bit of oiliness, which maybe could have migrated from outside, even though there is kind of a seal over the assembly (very light flexible plastic channels that set into the grooves on either side of the jockey wheel, with metal covers that cup to fit inside the channels).

Shimano's very helpful Technical Service Instructions say to "lubricate all moving parts" and "we highly recommend Shimano lubricants." :rolleyes:

Park Tool's website has a discussion of ceramic ball bearings (pictured in a hub IIRC), which they recommend packing in the same grease as metal ball bearings, but that's obviously not the same thing.

After searching generally, DH (former professional motorcycle mechanic with no b/c experience) advised putting it together with just a dab of engine oil, which is what I did so that I could get in my ride this morning.

I did put threadlocker on the fasteners since they'd had some before.

A call to the LBS is on the agenda for this afternoon, to find out if I need to take everything apart and re-do it!

ridebikeme
03-24-2008, 07:10 PM
Well, as everyone can see, there is a lot of conflicting information concerning ceramic bearings. Each time you gain some information, some other bits of information tend to show some conflict... HA! As for putting a touch of engine oil on the pulley, I DEFINITELY would NOT do that! Engine oil(WD40) tend to attract dirt and grime,and that it not something that you want ... especially around the drivetrain! It tends to wear things much quicker... like tiny bits of sandpaper.

Deb, good luck at your class this summer... sounds like fun! After being in the cycling industry for many years, I'm not convinced that we ever know everything... and that keeps everything fun and a challenge! Sometimes, even the manufacturers can't agree :):)

OakLeaf
03-25-2008, 09:13 AM
LBS says "a drop of oil." So, good, I'm leaving it the way it is :)

The seal over the bushings should be enough to keep out all but the finest grit. (It was before, and I was careful not to damage it and to put it back together properly.) And if I understand it correctly, the ceramic should be harder than most grit.

BTW, WD-40 is not engine oil! It's a mixture of kerosene and solvents. I agree about not using it for lubrication though!

ridebikeme
03-26-2008, 05:45 AM
Sounds like you have a good handle on things!

As for the engine oil/WD40 I realize that they are NOT one and the same! My mention of both is to simply say that they both attract dirt and grit... sorry for the confusion!

Get some outside miles in for me; we still have several feet of snow on the ground.... it will melt eventually :):)