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  1. #1
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    Need help-shimano FC-M443 crank & BB set

    I have been seeing this crank online but cannot see the picture well enough or find any info about what size /number bottom bracket is used with it. Anybody know?
    roccowt.
    rocnbikemeld

  2. #2
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    As always the best place to find information on Shimano parts is the Shimano website.

    Link to Service Instructions:
    http://techdocs.shimano.com/media/te...9830657937.pdf

    If you are looking at the FC-M443 (older square tapered BB) then you are looking at the BB-UN26 (-K). For the FC-M443-8 (newer octalink BB) then it's the BB-ES25 (-K). With the BB-UN26 (-K) you have the option of choosing a preferred chainline, either 47.5mm or 50mm, so choose the appropriate BB for your choice. With the BB-ES25 (-K) your chainline is 47.5 mm. Both model cartridges are available in 68mm or 73mm sizes to match your BB shell.

    Be very careful in specifying which model BB you want if you are ordering a BB-UN26 as there are two types, one with your choice of chainline and one with a set chainline plus offset if you're adding hardware.

    BB-UN26 (-K) non-chain case compatible. Your choice of chain line.
    BB-UN26-K chain case compatible. Chain line at 47.5mm + offset.

  3. #3
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    Quote Originally Posted by greyhorse
    As always the best place to find information on Shimano parts is the Shimano website.

    Link to Service Instructions:
    http://techdocs.shimano.com/media/te...9830657937.pdf

    If you are looking at the FC-M443 (older square tapered BB) then you are looking at the BB-UN26 (-K). For the FC-M443-8 (newer octalink BB) then it's the BB-ES25 (-K). With the BB-UN26 (-K) you have the option of choosing a preferred chainline, either 47.5mm or 50mm, so choose the appropriate BB for your choice. With the BB-ES25 (-K) your chainline is 47.5 mm. Both model cartridges are available in 68mm or 73mm sizes to match your BB shell.

    Be very careful in specifying which model BB you want if you are ordering a BB-UN26 as there are two types, one with your choice of chainline and one with a set chainline plus offset if you're adding hardware.

    BB-UN26 (-K) non-chain case compatible. Your choice of chain line.
    BB-UN26-K chain case compatible. Chain line at 47.5mm + offset.
    Thanks. ---zarr
    roccowt.
    rocnbikemeld

  4. #4
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    Wow the shimano part codes are confusing

    Arrgh. I thought I ordered the correct parts after reading through Shimano tech docs but now I'm not so sure. I came across this post doing a search to figure out what I did wrong.

    I got an Alivio FC-M410 (square taper) crankset and a "matching" BB-UN26-E bottom bracket to install on a bike with 50mm chainline. The label on the bottom bracket shows BB-UN26-E 68 LL113. The bike has a 68mm shell so at least this is correct.

    I threaded in the right (fixed) side on fully and when I proceeded to thread in the plastic adapter side the adapter stopped out with ~5mm of threads still showing. This does not look normal at all.

    The crank document shows BB-UN26 (-E) with spindle length LL113 (E) as the proper part. Was I supposed to get a BB-UN26 (-E)? Or BB-UN26?? The BB document lists BB-UN26 and -E, -K, -EK options but no (-E) option. Do I have the wrong adapter? I noticed the right side of the BB does not have threads right out to the shell stop. Am I supposed to insert a spacer here? I am really confused now!

  5. #5
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    Quote Originally Posted by buzz111
    Arrgh. I thought I ordered the correct parts after reading through Shimano tech docs but now I'm not so sure. I came across this post doing a search to figure out what I did wrong.

    I got an Alivio FC-M410 (square taper) crankset and a "matching" BB-UN26-E bottom bracket to install on a bike with 50mm chainline. The label on the bottom bracket shows BB-UN26-E 68 LL113. The bike has a 68mm shell so at least this is correct.

    I threaded in the right (fixed) side on fully and when I proceeded to thread in the plastic adapter side the adapter stopped out with ~5mm of threads still showing. This does not look normal at all.

    The crank document shows BB-UN26 (-E) with spindle length LL113 (E) as the proper part. Was I supposed to get a BB-UN26 (-E)? Or BB-UN26?? The BB document lists BB-UN26 and -E, -K, -EK options but no (-E) option. Do I have the wrong adapter? I noticed the right side of the BB does not have threads right out to the shell stop. Am I supposed to insert a spacer here? I am really confused now!
    Does your front derailleur fasten to the seat tube on your bike or between the bottom bracket and the bottom bracket shell?
    roccowt.
    rocnbikemeld

  6. #6
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    The derailleur is mounted to the tube with a clamp. The right (fixed) side of the BB is missing threads on only ~2mm so I don't think that's the problem.

    It seems like this BB kit is for a 68+5=73mm shell. Could it simply have been packaged with the wrong adapter size? What does the -E option on the BB-UN26 mean exactly? It's just not obvious to me from the tech document.

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