Steve Katzman |
03-16-10 02:09 PM |
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.
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