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  1. #1
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    Question about bottom bracket dimensions

    Hello,

    I'm building out a 2006 Specialized Epic Marathon. I'm taking some parts off of a 2002 Specialized Stumpjumper FSRxc Disc.

    Does anyone know if the bottom bracket from the 02 will work properly on the 06 Epic? The details of the 02 bb are:
    Shimano BB-ES-50E, splined taper (Octalink), 68x113 e-type

    I remember running into this issue when I built out the 02. I put the wrong BB in and , well, it wasn't good.

    The 06's spec page on specialized.com doesn't give the dimensions. It uses the newer Shimano M-760 XT, Hollowtech II, 2-piece crank/BB with the integrated piece.

    Any help would be appreciated.

    Thanks,
    /gC

  2. #2
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    You won't be able to use the BB....

    from your 02. The bb for your 03 is a 68x113mm. The E type thing wouldn't be a problem as all you would have to do to keep things correct is install a 1mm spacer between the bb housing and the drive side bb shell to compensate for the lack of the E type derailleur bracket. But the problem arises form the spindle length. The 03 Epics that were speced with splined bb's used a 113mm spindle length, in 04 they went to a 121mm, and then in 05 to a 118mm spindle, and of course in 06 all of the Epics from top to bottom were speced with the 2 piece intergrated bb system. The key here is maintianing the speced 50mm chain line for the 04 and newer Epics. If I remember correctly the spec for the 05 and 06 Epics didn't change in that respect, so you'll most likely need a 68x118mm bottom bracket for correct chain line.

    My suggestion would be to call (not email) Specialized and confirm this. Tell them EXACTLY what you are doing. I.E. you are building an 06 Epic Marathon frame, give the exact model and year of the crank you intend to use, and the exact model of bb (ES70,
    71, whatever) that you want to use, and you need to know the spindle length that you need to use. Be VERY specific about the bb model as some of the lower end Shimano ES bottom brackets required different spindle lengths to give the same chain line as the higher end models. I don't know how this worked out but it did and can be kinda confusing at times. But I'm betting that if you go with an ES 70 or 71bb that you'll need the 68x118. I'm just not 100% certain as (as you have noted) there's no spec given on the Specialized website due to the integrated bb's being used on all the Epics now.

    Anyway, bottom line is that you won't be able to use the bb out of your FSR.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  3. #3
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    I measured the outside width of the bottom bracket casing and it was more near 72.5mm (73mm?). Does this mean that it would actually require a 73mmx118mm bottom bracket?

    Thanks for all the info, btw. I'm going to call Specialized.

    /gC

  4. #4
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    Hmmm...interesting....

    I'm not to up on the newer Epics. It well could be that you'll need a 73mm shell! I know that some of Specs other bikes, SX Enduro and the Big Hit use 73mm bb's. Like I said, call Specialized on this one. They may have changed the spec for the Epic yet again!

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  5. #5
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    I took your advice and called Specialized (got the number from this forum! ) . The tech on the other end could never give me a definitive answer on what I'd need. I ended up having Jenson overnight me some of those fancy XTR cranks.

    Thanks!
    /gC

  6. #6
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    Now that's wasn't that bad of an idea.....

    That level of componentry is more suited to the Epic as a high end bike IMHO anyway. The cranks on the 02 Stump FSR XC weren't that top shelf anyway. Deffinately serviceable, but only around a Deore or LX level component by comparison. I assume you went with the M760 2 piece cranks. If so that's deffinately a good choice. No hassels with what size bb you need. That is the one thing (other than the stiffness and durability) of the new 2 piece designs that I love, you can buy em for one bike and then put them on any other bike you may own in the future. Different bb shell width, no worries! just add spacers to one side or the other.

    It kind of surprises me that the tech at Specialized couldn't give you a pat answer! But then who knows who they hire to answer the tech line. Coulda been some college kid that can use a computer to look things up but that's about it. Oh well, the problem is solved and you are ending up with a sweet crank set worthy of the ride it's going on. Have fun with the build and be sure to post some pics when it's done.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  7. #7
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    I picked these up:
    SHIMANO XTR FC-M960 CRANKSET
    Pewter, 172.5, 24/32/44T

    They were on sale at a really good price and Jenson was able to get them here overnight. I love their turnaround.

    I had Shimano XT cranks on the 02. The original cranks were el crappo.

    /gC

  8. #8
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    Ooops! My bad...

    I meant the 960's! Like I said, good choice they should perform well and look nice on the bike at the same time. Good luck with the build.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  9. #9
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    Thanks, so far so good. I ran into a snafu yesterday when I tried installing the derailer. Going off of what was on specialized's website, I bought a top swing derailer which doesn't fit. I ordered a new one. It just means I can't ride it this weekend. But, on the good side it gives me more time to double check everything, make sure everything is tight, and dial things in more.

    2 quick questions about those cranks. First, when I install the crank arm side, do I need to grease up the axel, or just leave as is? I saw a little bit of grease on it, but not much. 2nd question, when I installed the bottom brackets, I put one of the little 2.5mm adapters on the crank arm side, but didn't on the arm-only side (left). When I tightened down the arm only side, there was a gap. Now unless I didn't apply enough force, that gap was going to stay there, so I just put one of the spacers on that side. I don't think it will hurt anything, do you? But this leads me to believe something is up with the frame specs posted on their website or in the frame book, or shimano has a typo in their install docs.

    /gC

  10. #10
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    Are you say there is a gap....

    Quote Originally Posted by gateCrasher
    Thanks, so far so good. I ran into a snafu yesterday when I tried installing the derailer. Going off of what was on specialized's website, I bought a top swing derailer which doesn't fit. I ordered a new one. It just means I can't ride it this weekend. But, on the good side it gives me more time to double check everything, make sure everything is tight, and dial things in more.

    2 quick questions about those cranks. First, when I install the crank arm side, do I need to grease up the axel, or just leave as is? I saw a little bit of grease on it, but not much. 2nd question, when I installed the bottom brackets, I put one of the little 2.5mm adapters on the crank arm side, but didn't on the arm-only side (left). When I tightened down the arm only side, there was a gap. Now unless I didn't apply enough force, that gap was going to stay there, so I just put one of the spacers on that side. I don't think it will hurt anything, do you? But this leads me to believe something is up with the frame specs posted on their website or in the frame book, or shimano has a typo in their install docs.

    /gC
    between the bb housing of the frame and the bearing cup, or between the bearing cup and the crank arm? I'm not quite getting the drift.

    good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  11. #11
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    I think the bearing cup and crank arm. I went ahead and added some for good measure.

    /gC

  12. #12
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    Well, actually...more like the shaft that runs through the bottom bracket housing. The one connected to the crank arm.

  13. #13
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    I don't know of any reason to put them there....

    a spacer there won't really do anything. The bolts on the crank arm hold the arm in place. But if it dosn't interfere with anything and every thing fits as it should I guess it would be a good place to keep them so you don't loose em! Like I said, as long as everything fits tight and nothing wobles or wiggles you should be good to go. And you'll always know where those spacers are if you ever need them.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

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