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  1. #1
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    1997 Trek 1220 bottom bracket

    I think my bottom bracket is broken. The crank-set wobbles when I try to push it laterally. From what I understand, the bottom bracket is a Shimano BB-LP26, 118 mm spindle BB Shell Width 68mm English. I searched this up and cannot find a replacement. Also, does anyone know the torque specs for the bottom bracket screws and crank screw? What kind of taper is the Shimano BB-LP26 using?

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    Quote Originally Posted by jdmz View Post
    I think my bottom bracket is broken. The crank-set wobbles when I try to push it laterally. From what I understand, the bottom bracket is a Shimano BB-LP26, 118 mm spindle BB Shell Width 68mm English. I searched this up and cannot find a replacement. Also, does anyone know the torque specs for the bottom bracket screws and crank screw? What kind of taper is the Shimano BB-LP26 using?
    Will this work? http://www.amazon.com/Shimano-Square...ywords=bb-un55

  3. #3
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    All Shimano bottom brackets use the JIS taper (as far as I know). If you're using a cartridge bottom bracket and it's definitely the spindle wobbling in the bearings, it's worn out or broken.

  4. #4
    Senior Member Bill Kapaun's Avatar
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    Quote Originally Posted by jdmz View Post
    That'll work. The UN-55 is just a higher grade part.

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    DRF aka Thrifty Bill wrk101's Avatar
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    UN26 comes in a 117.5, I use them all of the time. I typically buy mine from Jensen, $50 minimum order for free shipping. They will match other prices on the web, so I usually do not have a problem coming up with $50 order.

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    Senior Member gyozadude's Avatar
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    If you're sure it's the BB, then the UN25 or UN55 should both work fine if you get the correct spindle length. Typically torque specs are printed on a sheet of instructions that comes with the BB unit and some BBs have a sticker with the specs on the BB-shell. But torque usually varies between 30 - 40 ft-lbs on the fixed cup, and 25 - 35 ft-lbs for the adjustable (or non-fixed cup).
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    I was looking at the UN26 too... But it only came in 68x117.5mm.... Do you think it will still work despite being .5mm shorter?

    I've already ordered the UN55 for $19 shipped at amazon... Seems like a good price compared to my lbs.

  9. #9
    Senior Member IthaDan's Avatar
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    Quote Originally Posted by jdmz View Post
    I was looking at the UN26 too... But it only came in 68x117.5mm.... Do you think it will still work despite being .5mm shorter?

    I've already ordered the UN55 for $19 shipped at amazon... Seems like a good price compared to my lbs.
    Just to add a visual to this, .5mm is about the thickness of a fingernail. There is much more clearance than that between the cranks and the chainstays.

    You'll be fine.

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