JayB

The Shimano XTR SGS M952 long cage rear derailleur on our tandem has done quite a few miles. Don't want to replace it as it works OK and has the barrel adjuster which, I think, is missing from the newer versions.

Jockey wheels are a bit worn. Does anyone what replacement jockey wheels would fit this rear derailleur best? I have heard that there are many different specs for rear jockey wheels.

Thanks,

Steve Katzman

Funny that you mention this subject. After about 23K miles on my tandem, I noticed while cleaning my chain about a month ago, that two teeth had broken off my lower jockey wheel on the Shimano XRT derailleur. I went through my bike junk collection and found a jockey pulley from an old 105 derailleur, and installed it for temporary duty, noting that this one had 10 teeth instead of the 11 on the original. I went about the search for a replacement pulley and found that they are extremely expensive if you want to replace with XTR. XT was like 1/2 the price. From the pictures I couldn't tell if there were any differences in materials or internal bushings. I decided to go with XT since I saw the XTR as a waste of money. Not to mention the confusion with different subgroups of the XT and XTR derailleurs, which I still haven't quite figured out yet (M739/M900/M950 etc).

To this day I haven't gotten around to replacing the temporary 105 that I put in there and have ridden the bike probably another 300 miles since. I have not noticed any degradation of shifting performance or any other degradation for that matter. I would recommend you get an XT or even lower grade, as it seems like all the Shimano pulleys are interchangeable. I would stay away from off brand (non Shimano) as I have heard that some may give inferior performance or service life. Of course there are many who might disagree and have had good results with the off brands, but that is only my opinion. The jockey pulley is not that much of a factor in overall performance so replacing a stock Shimano ceramic bushing with a ball bearing will affect the total drivetrain friction by something like .0001% and probably not last as long or be as impervious to dirt. Good luck.

Carbonfiberboy 

OTOH, I'm a great believer in aluminum jockey wheels with sealed ball bearings. I get mine from Performance. I've even replaced the wheels on new derailleurs. They used to sell them under Carmichael brand, but now they are Forte.

Steve Katzman

Why?

apage4u

Don't forget the top and bottom are different. If you mix them up you will have shifting problems.

Metzinger

Had this thread been posted in Mountain Biking, the OP would have been offered a hundred suggestions by now.

JayB

Thanks for the advice. I, too, would be interested in why aluminum jockey wheels are better.

joe@vwvortex

Not sure about the new ones but the old ones were noiser. I don't see how they are any better either - they don't last any longer and the newer oems are sealed. In all honesty - the XTR derailleur with that many miles on it is probably past the end of it's life. After installing Jagwire inline adjusters I don't miss not having a rear adjuster on the derailleur at all.