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  1. #1
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    Bonking ... not feelin' well Drivetrain Help!

    I ripped the rear derailluer off my 5 spot and when replacing it, it seemed like the front D was off when the bike was on the stand. A long story short, I messed up the placement and limits on the front D and my LBS has given up too. I think this has to do with the fact that an uncompressed suspension lines up the drivetrain differently than a compressed one. Anybody know how to get the front D lined up right? Thanks!

  2. #2
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    Quote Originally Posted by LGD98
    I ripped the rear derailluer off my 5 spot and when replacing it, it seemed like the front D was off when the bike was on the stand. A long story short, I messed up the placement and limits on the front D and my LBS has given up too. I think this has to do with the fact that an uncompressed suspension lines up the drivetrain differently than a compressed one. Anybody know how to get the front D lined up right? Thanks!
    I don't know much but until someone else chimes in...

    Can you be more specific about the FDer being off? AFAIK the alignment, with respect to the chainrings, should be the same regardless of the sus compression, or what chainring it's on...BUT you must have the der height properly set or the chainstay will tag the back of the F-Der at full compression and bend it.

    If you unbolt the top of your shock and move it out of the way, you can move the swing arm through it's travel. note: it will actually move more than the shock stroke so keep that in mind as to how far you swing it. If the chainstay/yoke hits the Fder within the nomal travel range, you'll have to raise up the Fder, and probably straighten it too .

    If you're not sure how much stroke you will get w/o the shock, you can always remove the spring and rebolt the shock to get a better feel for it. Keep in mind that the bumper on the shock shaft is ~1/2" thick and will compress at least 50% (probably 75%) at full travel so consider that extra travel if the Fder is already very close to the cs when the shock is on it's bumper.

    I can't imagine why the LBS is stumped. But if the Fder is bent, they should know it. Also someone might have rotated the der at the clamp, tail out or in, to clear the chainstay which could screw with a lot of things. It's better to have it straight and high than twisted and low.
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  3. #3
    No, that's not phonetic
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    Mount the f der at a height so the outer plate just barely clears the large chainring by 1-2mm when the plate passes over the ring (when you are shifing up). That sets the correct height.

    Next, look down from above and determine that the outer plate of the der is sitting either perfectly parallel to the outer chainring (when the two line up), or very slightly "tail out" (so the back of the der angles a tiny bit outboard of the plane the big ring sits in). The der is now in the correct position.

    Downshift into your lowest gear and adjust the low-end der stop screw so the der just barely does not rub the inboard side of the chain. This sets the der so the chain can downshift but not fall off the grannny.

    At this point, you may want to take up whatever cable slack there is when in the lowest gear with the der resting agianst the stop screw.

    Now shift into the middle ring in front and run through the gears in back. The der should not rub in the large cog in back, but will likely rub when in the smallest cogs in back. That is normal, and there is no way to get it not to rub in SOME cog when in the middle ring. Thank Shimano for that.

    The chain may drag over the lower part of the f der cage when the bike is on the stand, but with you on board and with the suspension partly compressed, this will go away.

    Let us know if the prob continues.
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  4. #4
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    Now there's a revalation...

    Quote Originally Posted by tscheezy
    ...Now shift into the middle ring in front and run through the gears in back. The der should not rub in the large cog in back, but will likely rub when in the smallest cogs in back. That is normal, and there is no way to get it not to rub in SOME cog when in the middle ring. Thank Shimano for that.
    That's something I've been trying to eliminate for a while now...it's good to see I'm not totally crazy. I'll thank you instead of Shimano. BTW is this a 9-speed thing? I don't recall having this problem on my 8spd HT.
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  5. #5
    No, that's not phonetic
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    9sp front ders are 0.5mm narrower in their cage than the 8sp was. Dunno if that is the issue since the chain is also narrower.

    Road STI levers have "meta-clicks" for trimming the front der to eliminate rub. I have no idea why they don't apply this feature to offroad components. Guess they think we couldn't figure it out.

    Just turn up your iPod and the chain rub goes away.
    My video techniques can be found in this thread.

  6. #6
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    Quote Originally Posted by LGD98
    I ripped the rear derailluer off my 5 spot and when replacing it, it seemed like the front D was off when the bike was on the stand. A long story short, I messed up the placement and limits on the front D and my LBS has given up too. I think this has to do with the fact that an uncompressed suspension lines up the drivetrain differently than a compressed one. Anybody know how to get the front D lined up right? Thanks!
    Tscheezy has it right!

    Like Bikezilla, I'm a bit confused by your description. There is nothing special about the front derailler on a 5 spot. The FD setup is the same as on a hardtail or any other standard bike configuration.

    I'd be concerned about your LBS if the only issue is how to mount and align the FD.

    Am I missing something? Why did the LBS have a difficult time and give up?

    Just curious.

  7. #7
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    Quote Originally Posted by Bikezilla
    That's something I've been trying to eliminate for a while now...it's good to see I'm not totally crazy. I'll thank you instead of Shimano. BTW is this a 9-speed thing? I don't recall having this problem on my 8spd HT.

    I think it is a 9spd thing, because like you my 8spd on my hardtail can span the entire range in the center chainring without rub. It would be nice if Shimano had two steps for the center chainring on the 9 speed like they do on their road stuff.

  8. #8
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    Quote Originally Posted by tscheezy
    9sp front ders are 0.5mm narrower in their cage than the 8sp was. Dunno if that is the issue since the chain is also narrower.

    Road STI levers have "meta-clicks" for trimming the front der to eliminate rub. I have no idea why they don't apply this feature to offroad components. Guess they think we couldn't figure it out.
    .
    Hmmm, actually I was wondering if the extra cog in the back made it difficult/impossible to eliminate front rub in the smallest rear cog. I'm guessing that even though the cogs are closer together than on a 8 spd, the cassette would still be wider. No matter though. I eventually decided I'd much rather spend my time riding the dammed thing.
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  9. #9
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    Follow-up

    Thanks for the help! The first issue is with the proper height.That's what I messed up first. The second issue was me messing up the limits. I'm sort of new at this. I took a maintenance class but....

    What is the best way to work off of what the LBS did? Pop off the shock and look at Up\Down alignement and then go through setting the limits? Should I be able to do all of this with the Romic on?

    The LBS just bailed after about 45 minutes. I think they couldn't compensate for the compression. Time to find a new LBS.

    Sorry for all the basic questions. I really hope I can get this tuned and don't have to send it back to WS in CA.

  10. #10
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    There's your problem right there...

    Quote Originally Posted by LGD98
    I really hope I can get this tuned and don't have to send it back to WS in CA. ...The LBS just bailed after about 45 minutes. I think they couldn't compensate for the compression.
    The LBS is ducking you b/c you didn't buy it from them. Follow Tscheezy's advice above first. You won't need to undo the shock to set it up right, that's just a paranoia check.

    It wouldn't hurt to download a .pdf of the fder setup instructions from Shimano(if available), believe it or not I actually found the hardcopy that came with my der helpful and easy to understand.

    Sheeesh, 45 minuets to set up a F der? how much of that time was a coffee break? Seriously, if it took more than 10, they had no friggin' idea what they were doing.
    Last edited by Bikezilla; 04-30-2004 at 01:59 PM.
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