Trouble shifting with 26T on Ultegra Triple

Discussion in 'Cycling Equipment' started by Roland Wooster, May 24, 2003.

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  1. I've just switched my 52/42/30 Ultegra granny gear to a 26 (stainless steel, specialized pro). The
    teeth are all identical, there appears to be no special ramp up or down modifications, but then
    again there doesn't seem to be much in the way of modifications for this purpose on the 30T either
    (unlike the 42T).

    However, the shifting from the middle gear to the granny often drops the chain past the granny and
    on to the frame. I could adjust the end stop of the front derailleur, but the problem there is it
    already rubs in first gear anyway.

    The other problem is that when shifting up from granny to the middle gear it often "misses" the
    middle gear jumps a little, then attemps to fall back onto the granny, but as the chain is so
    twisted by this point it misses the granny and falls onto the frame again.

    I'm pretty certain I got the crank back on the bottom bracket to a very similar spacing as when I
    took it off, as I use a torque wrench putting it on, so have a reasonable certainty the chain line
    is the same. And after the shifting failure I went back to the 30T and it works like normal again.

    Any suggestions? Is there some kind of device you can bolt on with the granny, using the granny's
    74mm bolt spacing that acts as an inner chain deflector so it can't derail itself?

    Thanks, Roland
     
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  2. Jim Price

    Jim Price Guest

    Roland Wooster wrote:
    > I've just switched my 52/42/30 Ultegra granny gear to a 26 (stainless steel, specialized pro). The
    > teeth are all identical, there appears to be no special ramp up or down modifications, but then
    > again there doesn't seem to be much in the way of modifications for this purpose on the 30T either
    > (unlike the 42T).
    >
    > However, the shifting from the middle gear to the granny often drops the chain past the granny and
    > on to the frame. I could adjust the end stop of the front derailleur, but the problem there is it
    > already rubs in first gear anyway.
    >
    > The other problem is that when shifting up from granny to the middle gear it often "misses" the
    > middle gear jumps a little, then attemps to fall back onto the granny, but as the chain is so
    > twisted by this point it misses the granny and falls onto the frame again.
    >
    > I'm pretty certain I got the crank back on the bottom bracket to a very similar spacing as when I
    > took it off, as I use a torque wrench putting it on, so have a reasonable certainty the chain line
    > is the same. And after the shifting failure I went back to the 30T and it works like normal again.
    >
    > Any suggestions?
    Your jump from the inner to middle chainring is 16 teeth. The manuals usually suggest no more than
    14 teeth as a single jump (although some people manage to get larger gaps working fine). A 38 tooth
    middle chainring is what I would try to see if it sorts the problem, preferably one with ramps and
    pins to make the shifting to/from the middle chainring better. Also, check that there is a clear
    chainline through the front derailleur with the chain in its lowest position (not fouling the bottom
    of the derailleur), and get the chain as short i.e. tight as possible so that it still works in the
    big-big ring combination. You don't mention the range of your cassette, but there is also a
    specification for how big a difference in number of teeth between highest and lowest gear that your
    rear derailleur can handle, and going way over this may be a problem. This might be curable with a
    longer cage derailleur.

    > Is there some kind of device you can bolt on with the granny, using the granny's 74mm bolt spacing
    > that acts as an inner chain deflector so it can't derail itself?

    If everything is working properly, you shouldn't need anything like this (because the front
    derailleur will keep the chain on), but such things do exist. They can be expensive, as they may be
    aimed at downhill racers who are always having to take extreme measures to keep the chain on.

    Jim Price
     
  3. Russell Yim

    Russell Yim Guest

    >Is there some kind of device you can bolt on with the granny, using the granny's 74mm bolt spacing
    >that acts as an inner chain deflector so it can't derail itself?

    Assuming all other attempts at adjustment fail (I imagine that part of the problem may be that you
    are trying to use a chainring size outside of Shimano's specifications), Third Eye makes a device
    called a Chain Watcher. It's a nylon/plastic "finger" that attaches with a hoseclamp to the seat
    tube. It allows for a more aggressive inward stroke adjustment of the front derailleur, and is
    shaped to guide a chain that overshifts back onto the granny ring.
     
  4. Grenouil

    Grenouil Guest

    "Roland Wooster" <[email protected]> wrote in message
    news:[email protected]...
    > I've just switched my 52/42/30 Ultegra granny gear to a 26
    (stainless
    > steel, specialized pro). The teeth are all identical,
    there appears to
    > be no special ramp up or down modifications, but then
    again there
    > doesn't seem to be much in the way of modifications for
    this purpose
    > on the 30T either (unlike the 42T).
    >
    > However, the shifting from the middle gear to the granny
    often drops
    > the chain past the granny and on to the frame. I could
    adjust the end
    > stop of the front derailleur, but the problem there is it
    already rubs
    > in first gear anyway.
    >
    > The other problem is that when shifting up from granny to
    the middle
    > gear it often "misses" the middle gear jumps a little,
    then attemps to
    > fall back onto the granny, but as the chain is so twisted
    by this
    > point it misses the granny and falls onto the frame again.
    >
    > I'm pretty certain I got the crank back on the bottom
    bracket to a
    > very similar spacing as when I took it off, as I use a
    torque wrench
    > putting it on, so have a reasonable certainty the chain
    line is the
    > same. And after the shifting failure I went back to the
    30T and it
    > works like normal again.
    >
    > Any suggestions? Is there some kind of device you can bolt
    on with the
    > granny, using the granny's 74mm bolt spacing that acts as
    an inner
    > chain deflector so it can't derail itself?
    >
    > Thanks, Roland

    With 52T big ring and 26 small you're strictly outside the (Shmano) spec of 22T difference.

    You could try a "Third Eye Chain Watcher" - designed to prevent dropping off the granny - Icycles
    has these for $7.00 - see http://www.icyclesusa.com/
     
  5. wkingson

    wkingson Guest

    On 24 May 2003 08:02:21 -0700, [email protected] (Roland Wooster) wrote:

    >Any suggestions? Is there some kind of device you can bolt on with the granny, using the granny's
    >74mm bolt spacing that acts as an inner chain deflector so it can't derail itself?

    See what Sheldon Brown has to offer...

    http://www.sheldonbrown.com/harris/drive.html#deflectors

    Bill Kingson Caribou, Maine
     
  6. Pete Biggs

    Pete Biggs Guest

    Roland Wooster wrote:

    > Any suggestions? Is there some kind of device you can bolt on with the granny, using the granny's
    > 74mm bolt spacing that acts as an inner chain deflector so it can't derail itself?

    I suggest experimenting with various derailleur positions (down, up, rotate, etc), then get one of
    the devices mentioned (Deda Dog Fang is another). I use an upside-down pump peg (has to be one just
    the right shape) - which helps my old Shimano mech cope with 24-40-52. The chain NEVER comes off now
    no matter how awkwardly or violently I shift!

    ~PB
     
  7. On Sat, 24 May 2003 08:02:21 +0000, Roland Wooster wrote:

    > I've just switched my 52/42/30 Ultegra granny gear to a 26 (stainless steel, specialized pro). The
    > teeth are all identical, there appears to be no special ramp up or down modifications, but then
    > again there doesn't seem to be much in the way of modifications for this purpose on the 30T either
    > (unlike the 42T).

    Grannies don't need these ramps and pins.
    >
    > However, the shifting from the middle gear to the granny often drops the chain past the granny and
    > on to the frame. I could adjust the end stop of the front derailleur, but the problem there is it
    > already rubs in first gear anyway.

    This is typical with a triple, especially with a small granny. The best advice is to get a Third Eye
    Chain Watcher. Works like a charm.

    --

    David L. Johnson

    __o | The lottery is a tax on those who fail to understand _`\(,_ | mathematics. (_)/ (_) |
     
  8. There are no pick up pins or special teeth on the 26 because the chain never has to climb up onto
    it, it's always dropped from above.

    I have a 26-44-48 on my tourer, and sometimes I get the same thing, especially if there's no tension
    on the chain. It is falling quite a distance after all. I solved this by always applying some
    pressure to the pedals, and not rushing the shift.

    If this doesn't work, there's a little plastic gadget that clamps to the right chainstay and guides
    errant chains back onto the granny.

    May you have the wind at your back. And a really low gear for the hills! Chris

    Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner
     
  9. Menno

    Menno Guest

    I use 26/38/50 with an Ultegra triple front deraileur.Works fine without any additional gadgets. As
    the cranckset and rings are TA, there are no ramp up/down helps on the chainrings. As someone
    mentioned earlier, the difference 26-42 is too large. So why not change the 42 to a 38 or 39. It
    will give you better spread gears as well.

    Menno

    "Roland Wooster" <[email protected]> wrote in message
    news:[email protected]...
    > I've just switched my 52/42/30 Ultegra granny gear to a 26 (stainless steel, specialized pro). The
    > teeth are all identical, there appears to be no special ramp up or down modifications, but then
    > again there doesn't seem to be much in the way of modifications for this purpose on the 30T either
    > (unlike the 42T).
    >
    > However, the shifting from the middle gear to the granny often drops the chain past the granny and
    > on to the frame. I could adjust the end stop of the front derailleur, but the problem there is it
    > already rubs in first gear anyway.
    >
    > The other problem is that when shifting up from granny to the middle gear it often "misses" the
    > middle gear jumps a little, then attemps to fall back onto the granny, but as the chain is so
    > twisted by this point it misses the granny and falls onto the frame again.
    >
    > I'm pretty certain I got the crank back on the bottom bracket to a very similar spacing as when I
    > took it off, as I use a torque wrench putting it on, so have a reasonable certainty the chain line
    > is the same. And after the shifting failure I went back to the 30T and it works like normal again.
    >
    > Any suggestions? Is there some kind of device you can bolt on with the granny, using the granny's
    > 74mm bolt spacing that acts as an inner chain deflector so it can't derail itself?
    >
    > Thanks, Roland
     
  10. Ken

    Ken Guest

    [email protected] (Roland Wooster) wrote in message
    news:<[email protected]>...
    > I've just switched my 52/42/30 Ultegra granny gear to a 26 (stainless steel, specialized pro). The
    > teeth are all identical, there appears to be no special ramp up or down modifications, but then
    > again there doesn't seem to be much in the way of modifications for this purpose on the 30T either
    > (unlike the 42T).
    >
    > However, the shifting from the middle gear to the granny often drops the chain past the granny and
    > on to the frame. I could adjust the end stop of the front derailleur, but the problem there is it
    > already rubs in first gear anyway.
    >
    > The other problem is that when shifting up from granny to the middle gear it often "misses" the
    > middle gear jumps a little, then attemps to fall back onto the granny, but as the chain is so
    > twisted by this point it misses the granny and falls onto the frame again.
    >
    > I'm pretty certain I got the crank back on the bottom bracket to a very similar spacing as when I
    > took it off, as I use a torque wrench putting it on, so have a reasonable certainty the chain line
    > is the same. And after the shifting failure I went back to the 30T and it works like normal again.
    >
    > Any suggestions? Is there some kind of device you can bolt on with the granny, using the granny's
    > 74mm bolt spacing that acts as an inner chain deflector so it can't derail itself?
    >
    > Thanks, Roland

    I've been using an Ultegra triple 52/42/26 on my tour bike for some time. Though not perfect it
    seems to shift pretty well most of the time. My shifters are Tiagra as well as my front derailor.
    Sometimes when the shifting seems to have lost sync I play around with the FD's limit screw and
    tinker with the barrel adjuster. This works for me. One final thought. My 26t granny is an aluminum
    one made by FSA. Also when in the granny ring I have no rubbing of the chain with the FD up to the
    second to the last gear. In the last gear I would get a slight rubbing sound.

    Kenny Lee
     
  11. wooster-<< However, the shifting from the middle gear to the granny often drops the chain past the
    granny and on to the frame

    yep, not uncommon since the angle is higher...get a chain watcher or 'third eye'....

    Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
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