My jockey wheel shattered!!!

As soon as I got my bike fixed I got it out for a ride this afternoon. It was about -5 celcius and for a reason I still don't know (I was hoping you could help me out!) my bottom jockey wheel cracked and fell in pieces!!!

My bike is 2 years-old and I'm equipped with Shimano Alivio rear derailleur.

Maybe was it caused by the cold temperature, the usual wearing out or wathever!??!?!?!?!

please help me out!!

thanks in advance

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That SUV makes you look fat.

any help plz......

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That SUV makes you look fat.

I would guess that is what simply worn out. Equipment on a bicycle wears out sooner than one would think. Chains should be replaced every 1200 to 1500 miles before it starts wearing out cassettes and chainrings. If this bike is used for commuting or is ridden a lot, most likely it is worn out. You can get replacement pulleys for that deraileur. They cost about 5-8 dollars.

More hooey. You replace chains by amount of elongation. 1/16" in a foot of tensioned chain.A foot of new chain measures exactly 12" center to center of pins.Mileage is meaningless, and entirely dependent on too many variables.

A brand new derailleur is probably only $25 or so. If the bike has over a thousand miles on it, it's not worth replacing a pulley that was worn out, damaged, or had a slight molding defect. I've spent a lot of time riding my Alivio-equipped hybrid in temperatures like that.

If it is a 24-speed system and you really like the bike, it might be worth spending the extra $10 to get an LX derailleur. If the bike is your 18 or 21-speed beater, spend some time scavanging in LBS junk boxes or the local thrift shop dumpster and you'll eventually find one for free.

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Bri
1,000,000 bicycles = 2 megacycles

Really? A LBS might even give you a perfectly good used one for nothing.

A lower pulley wheel is a lower pulley wheel,regardless of 'speed'. Bushing or bolt diameter may vary.

thanks a lot guys , I'm off for my bike shop to check this out , your advices are always appreciated!

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That SUV makes you look fat.

Really? The pulleys are all the same for 7, 8, or 9 speed. Are you sure there isn't a difference in width?

My bad.The 9 speed shimano is narrower enough to be an issue at least in some cases.7 and 8 speed seem to be the same width.

shimano's 9-speed pulleys are 11T vs. 10T too so even if width wasn't an issue, diameter could be.

i know that's the case at least down through 105

zewol, in response to your original question, very cold weather will make the plastic pulleys more brittle, and increase the potential to crack or shatter. That has GOT to have had something to do with it, since derailleur pulleys do not routinely break even after decades of use.

My guess is that the thing was very very cold, and cracked in reaction to some sort of external force--it got bumped, you went over a deep hole, the bearing froze and the chain exerted force on the pulley etc.

For something so unusual, Shimano will almost certainly replace the pulley under warranty. Call them, talk to them real nice, and you'll probably end up with a new set of pulleys for free.

Maybe shimano would replace it , but I don't think that 2 and a half years of riding still makes it eligible for the warranty...anyways , I'll try to get info at my local shop!!!


I ain't really sure because I dismounted it , but may have it been a factor that I would have inverted the two wheels or I doesn't have that much effect??? they looked the same on my bike but checked on my father's and there is one considerably wider...???!!!

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That SUV makes you look fat.

i haven't looked at my new 9-spd RD, but the 8-spd one i've taken apart definitely has 2 different pulleys. the upper one has some "float" to it while the lower one was fixed.

while swapping them may cause some decrease in the crispness of the indexing, i don't think it would create extra forces to shatter the pulley.

[QUOTE]Originally posted by zewol
[B]Maybe shimano would replace it , but I don't think that 2 and a half years of riding still makes it eligible for the warranty...anyways , I'll try to get info at my local shop!!!

The top and bottom pulleys are usually different, but if you didn't notice any difference when you mounted them, perhaps they're the same on your derailleur.

In my experience, when something fails in an extraordinary way, Shimano, if asked, will consider making an exception to its warrantly period limits, and will replace the part. They recently gave me a new set of Ultegra tandem cranks that was about three years old, and had had some unusual problems.

I trust it may be easier for a $8 part, but then again, it may not be worth the trouble for an $8 part.