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  1. #1
    Chrome Toaster
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    Why do you have to replace them?

  2. #2
    Pedalphile
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    Piece of crap XTR!!!!

    250 miles- 4 months- and I have to replace BB cups for XTR cranks!!!! My '05 Dakar Pro was not abused, carried over water crossings and not washed with high water pressure. YET, the most expensive BB in Shimano's stable is crapping out. Shitmano is the new name for their stuff.
    [SIZE=3]"A witty saying proves nothing."- Voltaire[/SIZE]


    Eric

  3. #3
    Pedalphile
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    Quote Originally Posted by Hecubus
    Why do you have to replace them?
    Bearings failed
    [SIZE=3]"A witty saying proves nothing."- Voltaire[/SIZE]


    Eric

  4. #4
    mechmann_mtb
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    the person that installed the cranks probably "cranked down" on the plastic piece that threads onto the non-drive side, placing too much side load on the bearings and trashing them.

    i think that the new external bearing cranksets require some getting used to by mechanics. when i first got my enduro i took it apart to check everything and the shop had tightened that plastic piece to the point that the cranks wouldn't even spin for half a revolution unassisted. (monkeys with poo to fling is bad, monkeys with wrenches are just horrible!) this much side loading on the bearings will definitely cause premature failure.

    the old BB didn't require any finesse to set up the bearing load. you litterally "cranked down" on the crank bolts to keep them from loosening.

  5. #5
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    Bummer

    Hopefully it's an installation issue as indicated by mechmann. Have you contacted the LBS to see if it will be warrantied? My guess is that it should be covered.

    Bob
    'If Wal-Mart sold parachutes, who would jump?' Frank Havnoonian (quoting his father) Drexel Hill Cyclery

  6. #6
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    I highly doubt the bearings have failed so soon. For them to fail they must have been seriously sideloaded which is very difficult to do with the shimano design. Your bearings most likely just need grease. It happens with new bearings. The quality and quantity of grease they bring is not enough. Pop the covers off and squeeze some good high quality grease in there and I bet they will roll good again.

  7. #7
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    Also had problems with the XTR

    I had to replace the cups twice in one season. I cannot say that I was really consious of avoiding water like Hebus, I certaininy splash through the streams, but I have BB that have lots ofseasons in them without a problem. The chainrings seem to be made of cardboard too. 2 sets in One season just like the cups. (Yes I change chains) My cups were changed caused they creaked incessently, never had them not spin. Anyway, I with ya on the New generation XTR stuff. To expensive to fall apart.

    Sorry to hear that. Pedal

  8. #8
    Neg reppers r my biatches
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    Quote Originally Posted by HPilot
    Shitmano is the new name for their stuff.
    fyi - that name has been around for a while now

  9. #9
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    on the other hand i bought a hollow tech xt when they were brand new. since then i've greased the bearings once, and they've run perfectly. the middle and outer rings did snap though. almost perfecly 1/4 each time direcly between where the holes were drilled to attach them. i definately didn't bang them.

  10. #10
    Neg reppers r my biatches
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    i was actually sort of kidding anyway....I only use Shimano pedals. The best front der is still no doubt the XTR. But because I love twist shifting and find the 1:1 actuation of SRAM much better than Shimano, not to mention the WAY lessened chain slap, I will never use a Shimano drivetrain again.

  11. #11
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    Quote Originally Posted by Pedalfaraway
    I had to replace the cups twice in one season. I cannot say that I was really consious of avoiding water like Hebus, I certaininy splash through the streams, but I have BB that have lots ofseasons in them without a problem. The chainrings seem to be made of cardboard too. 2 sets in One season just like the cups. (Yes I change chains) My cups were changed caused they creaked incessently, never had them not spin. Anyway, I with ya on the New generation XTR stuff. To expensive to fall apart.

    Sorry to hear that. Pedal
    A squeeking cup is not a failed cup and certainly came nowhere near falling apart as you state. It's the first and most obvious sign that they need lube. If you keep riding them like that they will seize up and get destroyed at which point will truly be obvious since they cranks will pretty much stop turning. If you replaced them every time they squeeked then you threw away $50 each time. Next time just put in some high quality dense grease and you should go a year or two before needing any service. I've had two sets of XTR's. One of them is the very earliest one from October 2002 when they came out and has been on my race bike since. Conditions here are hardly dry and most of the races and courses had entire sections that were submerged in water due to heavy rains throughout the year. Nowhere near an ideal enviroment. They are still running perfectly. They sqeaked after about 6 months. I packed them with Pedro's Syn grease and it has proven superb at keeping them rolling smooth. They only need preventive maintenance once every year to year and a half. Outboard bearings are very exposed and its ludicrous to think any kind of sealed bearing will last indefinately. They need service just like everything else. If you take cere of them believe me you will have very little reason to ever replace them.

  12. #12
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    http://forums.mtbr.com/showthread.php?t=136309

    This should give you an idea of what I mean. My most recent cranks are a set of Race Face Deus. During the first three months I could see the CRAP factory grease ooze out in liquid form through the outside cap. One day the cranks seized hard. Take a look at the picture with the clea polished looking bearing. Thats not what it looked like after cleaning it. Thats what it looked like after taking the cover off! The grease had washed away completely. Put in my trusty grease and they were golden again. Anyone who didn't know would have thrown them out as destroyed bearings when they were still perfectly fine.

  13. #13
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    Greasing the cups did not resolve the creaking on mine.

    It was tried several times prior to replacement. Maybe I just waited too long, but I only had the crankset for a year, and with the 2 sets of replacements, and mulpiple attempts to grease the creaks away I imagine they were greased at least once a month.

  14. #14
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    Race Face X Type

    I have more than two years on my Race Face BB with lost of watter crossings and some pretty wet ridding and it is perfect. They are interchangable with Shimano and they are also cheaper I think.

  15. #15
    mechmann_mtb
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    i've got 6 mo's on my XT crankset and a bit less than that on the wife's XTR crankset. both BB have had zero problems. granted i am pretty meticulous about my maintenance, but i really beat on my bike hard as evidenced by a broken chain stay within 6 months on a "black diamond trail bike".

  16. #16
    Pedalphile
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    Installation

    Quote Originally Posted by mechmann_mtb
    the person that installed the cranks probably "cranked down" on the plastic piece that threads onto the non-drive side, placing too much side load on the bearings and trashing them.

    i think that the new external bearing cranksets require some getting used to by mechanics. when i first got my enduro i took it apart to check everything and the shop had tightened that plastic piece to the point that the cranks wouldn't even spin for half a revolution unassisted. (monkeys with poo to fling is bad, monkeys with wrenches are just horrible!) this much side loading on the bearings will definitely cause premature failure.

    the old BB didn't require any finesse to set up the bearing load. you litterally "cranked down" on the crank bolts to keep them from loosening.
    Jamis factory bike, so not sure how much LBS had to build prior to delivery. I'm pissed to see others with pre-mature failure and no warranty by Shimano. My LBS id checking on the warranty of the issue.
    [SIZE=3]"A witty saying proves nothing."- Voltaire[/SIZE]


    Eric

  17. #17
    mechmann_mtb
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    something i learned when i raced RC cars, always break down the machine to make sure everything is good. pull the cranks and check to make sure the bearings are smooth, chain is correctly lubed, cassette is tight, freewheel is working right, etc. a few hours spent tearing the bike down and putting it back together can save a TON of money/grief. just because the cranks came from Jamis/or wherever (not saying they did or didn't) overtightened (if that was indeed the mechanism causing the failure) doesn't mean it was shimano's fault.

  18. #18
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    Have your BB faced by a good LBS if you are running ext. bearing cranks. If they don't fit square in the BB they can cause all kinds of problems. Not always the problem but a good place to start troubleshooting.
    Slowly slipping to retrogrouchyness

  19. #19
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    If the creaking of your cups only happens under load, it is probably some dirt in the threads of the bottom bracket cup. Just remove the cups and clean the threads well and grease them up. Some people like putting plumber's latex tape on the threads.

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