Results 1 to 12 of 12
  1. #1
    mtbr member
    Reputation: italywimp's Avatar
    Join Date
    Feb 2006
    Posts
    38

    05 stumpy Expert 120 build gone bad, help

    I got a great deal on this frame and so began the saga of building it.

    I didnt want to transfer all the old parts off my old hardtail but I did transfer some that were still good. So I will list the parts.

    I replaced most of the drivetrain with the build, my XT casette from the hardtail was still almost new from my old bike so that stayed. I did replace the cranks to the 2004 Shimano LX hollowtech's, Also bought a new sram 8 speed chain (this is a 8 speed setup) I also replaced my wheels/hubs (mavic 717) to accomodate the new Avid BB7 mech disc brakes, but there is no problem there, only the shifting.The problems with shifting I am experiencing is pretty much everything, Mystery shifts under load, front derailer rub in granny gears, in fact no gear is without some problem or another.


    I have brought it to the shop twice now with no fix, the last time I was there the mechanic told me that the front de-railer is not compatible with the frame, but this came with the frame and is the stock front derailer from the origional factory build. Are front derailers 8 or 9 speed specific?? I am sure this bike was 9 speed off the shelf, maybe that is the problem?.

    All I knwo is that everytime I ride the shifting blows up on me, mystery shifting, front derailer rub in almost every gear. And I dont ride the gears badly at all. I am trying to figure out where is the problem, my rear XTR derailer performs just fine, although it is a few years old, it shifts perfectly, the problem seems to be in the front.

    Could it be that my cranks are not spaced out to spec, Do they need spacers, any thoughts??

  2. #2
    Gravity Rides Everything
    Reputation: endurowanker's Avatar
    Join Date
    Mar 2004
    Posts
    1,127
    the LX cranks should have come with spacers (i'm assuming outboard bearing new style cranks right?)
    there will be 2 spacers between the frame and the drive side bearing, and 1 spacer on the left side.

    that may be your issue. sounds like a chainline prob to me

  3. #3
    mtbr member
    Reputation:
    Join Date
    Dec 2005
    Posts
    113
    If your crank is not out board bearings do you have a mismatch between the crank and BB? Are you using the stock BB? Your front derailleur should work fine with 8 speed, at worst a little more chain rub.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Dec 2005
    Posts
    113
    Sorry, you need a 9 speed chain with a 9 speed crank! This will work fine with the 8 speed rear.

  5. #5
    mtbr member
    Reputation: italywimp's Avatar
    Join Date
    Feb 2006
    Posts
    38
    I bought the LX crank off ebay on this site, it is the 2004 style, (Shimano Deore LX FC-M572 9-Speed Crankset) link http://cgi.ebay.com/NIB-SHIMANO-DEOR...QQcmdZViewItem

    I realise that it says nine speed cranks, so you cannot use these cranks as 8 speed?, Also if I need to upgrade to 9 speed, do I have to replace the front derailer as well, I assume not.

    I didnt realise but now I guess I will have to buy a new shifter, rear derailer, chain and cassette.

    this sucks, the only thing I was able to hang on to was the damn front derailer shifter.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Dec 2005
    Posts
    113
    You can use the cranks, 9 speed front derailleur, 8 speed cassette and 8 or 9 speed rear derailleur no problem. With 9 speed chain rings you must use a 9 speed chain. The spacing is too narrow for an 8 speed chain. The 9 speed chain will work fine with the 8 speed cassette and all your other 8 or 9 speed components..

  7. #7
    -> SickLines.com <-
    Reputation: mtb_biker's Avatar
    Join Date
    Jan 2004
    Posts
    3,213
    It is a common problem with ghost shifting with full suspensioon. Make sure you have a good amount of cable underneath the linkage under the front derailleur. Often what will hapeen is the cable will get pulled as the bike traverses through its travel making the rear derailleur shift.

    Another thing to check is your chainline and bottom bracket spindle width.

  8. #8
    mtbr member
    Reputation: italywimp's Avatar
    Join Date
    Feb 2006
    Posts
    38
    I am putting the spacers on right now, 2 on the drive side. Hoping this will fix it. I am going to leave the left side alone.

    I thought and was told by my shop the 8 speed chain should be ok with these cranks, it turns ok on the crank wheel, doesnt skip or come loose, it is only the front derailer rub that is the problem and the rear cassette slipping the chain. The shop coudl be wrong, but the guy helping me seems to know his Sh@#T

  9. #9
    NormalNorm
    Reputation: norm's Avatar
    Join Date
    Feb 2005
    Posts
    935
    [QUOTE=mtb_biker]It is a common problem with ghost shifting with full suspensioon. Make sure you have a good amount of cable underneath the linkage under the front derailleur. Often what will hapeen is the cable will get pulled as the bike traverses through its travel making the rear derailleur shift.

    QUOTE]

    I had the same problem with ghost shifts. Another vote for more cable underneath the bottom bracket. Added abit more cable and the problem was solved.....

  10. #10
    mtbr member
    Reputation: italywimp's Avatar
    Join Date
    Feb 2006
    Posts
    38
    Turns out my bottom bracket was the wrong one and I needed a 118 shimano bbes71 not the 113 that is in there. So I may not need the spacers after all. we will find out tomorrow I guess

  11. #11
    Just ride!
    Reputation: tennessee17's Avatar
    Join Date
    Oct 2004
    Posts
    316

    I do not know the answer......

    But I am willing to wager Herbecus (sp?) on these boards does. Hi avatar is a knights helmet. I am always amazed at the acccuracy of this posts, especially concerning drivetrain stuff. Look up Herbecus and PM him. He will shoot you straight!

  12. #12
    mtbr member
    Reputation: italywimp's Avatar
    Join Date
    Feb 2006
    Posts
    38
    So now I have the right bottom bracket, it needed a 118/68 bb and that fixed the shifting issues, not sure if the guy put it on right though as it seems to click or move a bit while cranking really hard on the downpedal. I am pretty bumbed right now, as I feel like the mechanic is not able to tune this bike properly for lack of stumpjumper experience (not a specialized store).

    I probably have to bring it elsewhere now and start over. I believe he did use the spacers, but like I say it seems to click and make noise on hard cranking.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •