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Bent hanger --> Bent frame? ... shifting problems

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Cycling Equipment
Published
4 October 2007
Last activity
8 October 2007
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DaveH
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  1. [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]

    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.

    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.

    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.
    Dave

  2. M-gineering said:

    Bent frame isn't very likely with just toppling over. If you can ride
    the frame no handed without the frame veering left or right it's fine.
    I'd investigate free movement of the shiftercable first. Is the cable
    properly located underneath the bracket? Last bit of outer cable not to
    short, kinked, badly cut. missing ferrule etc? And another good one:
    cable properly clamped in the groove on the derailleur body?

    Not to mention, bent frames are more likely to affect the movement at
    the limits, not in the middle of the cog. It's possible, but I would
    think the bend would have to be severe for that to happen.

    How good a job did they do on the hanger straightening? Any chance
    they left it "non flat" ?

  3. DaveH said:

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Try the "string test" to check frame alignment:

    http://sheldonbrown.com/frame-spacing.html
    (scroll down near the bottom)

    Also make sure the shift wire is anchored at the correct place on the
    derailleur.

    Art Harris

  4. On Thu, 04 Oct 2007 17:51:02 GMT, still me <[email hidden]>

    Quoted message said:
    M-gineering said:

    Bent frame isn't very likely with just toppling over. If you can ride
    the frame no handed without the frame veering left or right it's fine.
    I'd investigate free movement of the shiftercable first. Is the cable
    properly located underneath the bracket? Last bit of outer cable not to
    short, kinked, badly cut. missing ferrule etc? And another good one:
    cable properly clamped in the groove on the derailleur body?

    Not to mention, bent frames are more likely to affect the movement at
    the limits, not in the middle of the cog. It's possible, but I would
    think the bend would have to be severe for that to happen.

    How good a job did they do on the hanger straightening? Any chance
    they left it "non flat" ?

    Marten and Still,
    I did the string test for rear triangle displacement at:
    http://www.faqs.org/faqs/bicycles-faq/part3/section-50.html

    The test indicates the seat tube deviates to the right by 1/16". This
    suggests the rear tri is displaced 1/32" to the left. This doesn't
    sound like much; but indeed, I just did some extensive no-hands riding
    and there is a mild but distinct tendency to veer to the right.

    I thought something didn't feel right about the ride feel before a
    bent frame even occurred to me but it was a bit vague and assumed it
    was my imagination.

    Still, you would not think this would be enough to effect shifting,
    especially in the middle cogs as noted. I talked to Rivendell and they
    agree with this.

    Regarding hanger straightening: The LBS appeared to take his time with
    what is obviously a special tool. I must assume at this point that
    it's ok.

    Regarding cable issues Marten: Everything's ok, as far as I can tell.
    Not sure what to do. I'm tempted to put an Ultegra derailleur back on
    it.

    I live in the sticks and this LBS is not equipped to straighten
    frames. The FAQ page suggests manual straightening. Not crazy about
    that idea. I'll figure it all out.
    Dave

  5. On Thu, 04 Oct 2007 11:23:49 -0700, Art Harris <[email hidden]>

    Quoted message said:
    DaveH said:

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Try the "string test" to check frame alignment:

    http://sheldonbrown.com/frame-spacing.html
    (scroll down near the bottom)

    Also make sure the shift wire is anchored at the correct place on the
    derailleur.

    Art Harris


    Art,
    Please see my latest post in the original thread.
    Thanks -- Dave

  6. DaveH said:

    [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]

    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.

    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.

    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.

    Much more likely to be a simple error/oversight; derailleur
    alignment/adjustment/cable problem. You should be able to return to the
    shop which 'upgraded' your gear system and watch the Campagnolo "R" tool
    alignment then a full frame alignment gauge. If the rear end were off to
    one side enough to give shifting problems, you'd likely have noticed a
    difference when riding no hands.
    p.s. if there are plastic ferrules on your casing, have them replaced
    with real ones.

    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971

  7. DaveH said:

    [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]

    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.

    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.

    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.
    Dave

    Bent frame isn't very likely with just toppling over. If you can ride
    the frame no handed without the frame veering left or right it's fine.
    I'd investigate free movement of the shiftercable first. Is the cable
    properly located underneath the bracket? Last bit of outer cable not to
    short, kinked, badly cut. missing ferrule etc? And another good one:
    cable properly clamped in the groove on the derailleur body?

    --
    /Marten

    info(apestaartje)m-gineering(punt)nl

  8. On Thu, 04 Oct 2007 15:57:48 -0500, A Muzi <[email hidden]>

    Quoted message said:
    DaveH said:

    [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]

    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.

    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.

    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.

    Much more likely to be a simple error/oversight; derailleur
    alignment/adjustment/cable problem. You should be able to return to the
    shop which 'upgraded' your gear system and watch the Campagnolo "R" tool
    alignment then a full frame alignment gauge. If the rear end were off to
    one side enough to give shifting problems, you'd likely have noticed a
    difference when riding no hands.
    p.s. if there are plastic ferrules on your casing, have them replaced
    with real ones.

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

  9. DaveH said:

    On Thu, 04 Oct 2007 15:57:48 -0500, A Muzi <[email hidden]>

    Quoted message said:
    DaveH said:

    [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]

    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.

    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.

    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.

    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.

    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.


    Much more likely to be a simple error/oversight; derailleur
    alignment/adjustment/cable problem. You should be able to return to the
    shop which 'upgraded' your gear system and watch the Campagnolo "R" tool
    alignment then a full frame alignment gauge. If the rear end were off to
    one side enough to give shifting problems, you'd likely have noticed a
    difference when riding no hands.
    p.s. if there are plastic ferrules on your casing, have them replaced
    with real ones.

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

    Doesn't sound likely. Does the DA rear have a weaker spring than the
    original? Sluggish shifting to smaller sprockets is usually because the
    spring is too light for the friction in the path.

  10. Quoted message said:
    Quoted message said:
    DaveH said:

    [58 cm Rivendell Ramboulliet -- steel frame, Dura Ace bar ends]
    Days ago I had a clipless newbie style slow-speed side crash which
    bent the derailleur hanger and the Ultegra rd-6500gs triple der. My
    LBS straightened the hanger and replaced the bent der with a Dura Ace
    rd-7700GS.
    The new der shifted fine on the stand -- but on the road I
    experienced problems, particularly when downshifting from 15 to 14
    teeth cogs (Ultegra 12-27, 9 sp cassette). The prob seems to be
    erratic, not yielding to any amount of adjustment.
    Rivendell suggested the frame may have been bent in the crash --
    triangle pushed to the left. It looked like the hanger was bent
    something on the order of 2-3 degrees -- wild visual guess.
    Generally, how frequently is a bent hanger accompanied by a bent
    frame? Tough question, I know. My immediate concern is whether I need
    to find a shop that is equipped for frame checking and alignment.
    I've read Sheldon and others regarding bent hangers and I've not seen
    bent frames being mentioned as an associated issue, though the
    possibility is obvious.

    Quoted message said:
    A Muzi said:

    Much more likely to be a simple error/oversight; derailleur
    alignment/adjustment/cable problem. You should be able to return to the
    shop which 'upgraded' your gear system and watch the Campagnolo "R" tool
    alignment then a full frame alignment gauge. If the rear end were off to
    one side enough to give shifting problems, you'd likely have noticed a
    difference when riding no hands.
    p.s. if there are plastic ferrules on your casing, have them replaced
    with real ones.

    DaveH said:

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

    Crank's not the problem.
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971


  11. Quoted message said:
    DaveH said:

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

    Crank's not the problem.

    I replaced the DA 7700gs rear derailleur with a new Ultegra 6500gs.
    It now shifts perfectly. Smoother, more incisive -- it is a mystery.

    Now I must solve the bent frame problem. No hands it veers right,
    requiring a slight left body lean to maintain a straight line. I had
    an experienced friend confirm this. Mild, not terminal, but
    psychologically intolerable.

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".
    Dave

  12. Quoted message said:
    Quoted message said:
    DaveH said:

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

    Quoted message said:
    Quoted message said:

    Crank's not the problem.

    DaveH said:

    I replaced the DA 7700gs rear derailleur with a new Ultegra 6500gs.
    It now shifts perfectly. Smoother, more incisive -- it is a mystery.

    Now I must solve the bent frame problem. No hands it veers right,
    requiring a slight left body lean to maintain a straight line. I had
    an experienced friend confirm this. Mild, not terminal, but
    psychologically intolerable.

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".

    Good guess, but I'd look for a place where you can watch steel gauges on
    the frame before you start pulling on the rear end.
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971

  13. DaveH said:
    Quoted message said:
    DaveH said:

    I wonder if the Dura Ace 7700gs triple rear derailleur is incompatible
    with my Sugino XD-2 48/36/36 crank since the problem is worst on the
    largest chainring, though I know that can be typical.

    Quoted message said:

    Crank's not the problem.

    I replaced the DA 7700gs rear derailleur with a new Ultegra 6500gs.
    It now shifts perfectly. Smoother, more incisive -- it is a mystery.

    Now I must solve the bent frame problem. No hands it veers right,
    requiring a slight left body lean to maintain a straight line. I had
    an experienced friend confirm this. Mild, not terminal, but
    psychologically intolerable.

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".
    Dave

    I'd take it too him if you can; trying to fix it on your own without
    any prior experience suggests that you might wind up ruining the
    frame. sometimes it pays to have the job done right even if you have
    to pay someone else to do it. It sounds like you would appreciate a
    good job well done- it might be a 2hr drive for you, but surely you
    spend much more time than that weekly riding your bike and when you do
    your mind should be free of issues regarding your frames alignment


  14. Quoted message said:
    Quoted message said:

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".

    Good guess, but I'd look for a place where you can watch steel gauges on
    the frame before you start pulling on the rear end.

    Of course, lest I make the situation worse. Thanks --
    Dave


  15. Quoted message said:
    Quoted message said:

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".
    Dave

    I'd take it too him if you can; trying to fix it on your own without
    any prior experience suggests that you might wind up ruining the
    frame. sometimes it pays to have the job done right even if you have
    to pay someone else to do it. It sounds like you would appreciate a
    good job well done- it might be a 2hr drive for you, but surely you
    spend much more time than that weekly riding your bike and when you do
    your mind should be free of issues regarding your frames alignment

    Yes, of course -- you are right.

    There's something about a bent frame--even if minor and rideable--that
    is terribly bothersome. Chips, nicks and other flaws aren't an issue.
    Even mechs that are not perfect. But the frame is the soul of the
    machine, and a bent one on a bike like this Riv Rambouillet is rather
    heartbreaking, frankly.

    Maybe that's going over the deep end, but after riding a bike for many
    miles, it becomes an extension of the body.
    Dave

  16. DaveH said:
    Quoted message said:
    Quoted message said:

    I'm guessing I can find a frame man near Wash DC, 2 hours away.
    It is tempting to try the FAQ's manual straightening method. I think
    the rear-end needs to be pulled to the right ~1/16".
    Dave

    Quoted message said:

    I'd take it too him if you can; trying to fix it on your own without
    any prior experience suggests that you might wind up ruining the
    frame. sometimes it pays to have the job done right even if you have
    to pay someone else to do it. It sounds like you would appreciate a
    good job well done- it might be a 2hr drive for you, but surely you
    spend much more time than that weekly riding your bike and when you do
    your mind should be free of issues regarding your frames alignment

    Yes, of course -- you are right.

    There's something about a bent frame--even if minor and rideable--that
    is terribly bothersome. Chips, nicks and other flaws aren't an issue.
    Even mechs that are not perfect. But the frame is the soul of the
    machine, and a bent one on a bike like this Riv Rambouillet is rather
    heartbreaking, frankly.

    Maybe that's going over the deep end, but after riding a bike for many
    miles, it becomes an extension of the body.
    Dave

    The evil bike mechanic on my shoulder just muttered "I don't know,
    princess... 1/16" is an awfully small pea."

    -Vee


  17. Quoted message said:
    Quoted message said:

    Maybe that's going over the deep end, but after riding a bike for many
    miles, it becomes an extension of the body.
    Dave

    The evil bike mechanic on my shoulder just muttered "I don't know,
    princess... 1/16" is an awfully small pea."

    -Vee


    Evil yes, but quality evil -- which makes all the difference.
    Dave

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