Unusable gear combinations on a triple/9 setup?

Discussion in 'Cycling Equipment' started by Kovie, Oct 18, 2003.

Thread Status:
Not open for further replies.
  1. Kovie

    Kovie Guest

    I'm sure that this is a very common question but I can't seem to find an answer to it. I'm building
    up a new road bike with triple front/9 rear gearing. Are there any combinations of gears that are
    either impossible, or at least unrecommended due to excessive chain flex, derailleur rub or wear,
    chainstay rub, etc.? I know that on my old 2x7 road bike the extreme combinations were effectively
    unusable, but I'm wondering how this works with a 3x9.

    Also, does it make a difference as to which make and model of cranks, cassette, chain and
    derailleurs one uses? I'm most likely going to go with Shimano Ultergras, but there's a chance I'll
    go with Campy Chorus or Centaur.

    If there are online resources that answer this sort of question, that would be great too.

    Thanks!

    --
    Kovie [email protected]
     
    Tags:


  2. Kovie

    Kovie Guest

    I forgot to mention that I'm getting a 30-42-52 front, and either a 13-23 or 13-25 rear.

    --
    Kovie [email protected]

    "Kovie" <[email protected]> wrote in message news:[email protected]...
    > I'm sure that this is a very common question but I can't seem to find an answer to it. I'm
    > building up a new road bike with triple front/9 rear gearing. Are there any combinations of gears
    > that are either impossible,
    or
    > at least unrecommended due to excessive chain flex, derailleur rub or
    wear,
    > chainstay rub, etc.? I know that on my old 2x7 road bike the extreme combinations were effectively
    > unusable, but I'm wondering how this works with a 3x9.
    >
    > Also, does it make a difference as to which make and model of cranks, cassette, chain and
    > derailleurs one uses? I'm most likely going to go with Shimano Ultergras, but there's a chance
    > I'll go with Campy Chorus or Centaur.
    >
    > If there are online resources that answer this sort of question, that
    would
    > be great too.
    >
    > Thanks!
    >
    > --
    > Kovie [email protected]
     
  3. Tom Paterson

    Tom Paterson Guest

    >From: "Kovie"

    > If there are online resources that answer this sort of question, that would
    >> be great too

    <http://groups.google.com/ >

    Looking at "triple chainrings" in a search of rec.bicycles.tech:

    <http://groups.google.com/groups?q=triple+chainrings+group:rec.bicycles.te
    ch&hl=en&lr=&ie=UTF-8&group=rec.bicycles.tech&scoring=d>

    for starters. ("Arrange by date")

    Suggest you chart out your prospective gears, compare to your experience with what ratios
    you've used.

    Campy levers are rebuildable, Ultegra not. The biggest "Italy v. Japan" difference in use is the
    actuating lever arrangement. It might be a good idea to try out both to see which one you like best
    if you haven't yet done so.

    The idea of not running a crossed-over chain remains the same. You'll have more usable gears, and
    more "duplicates" or combinations that are close to the same gear ratio. --Tom Paterson
     
  4. Grenouil

    Grenouil Guest

    "Kovie" <[email protected]> wrote in message news:[email protected]...
    > I'm sure that this is a very common question but I can't
    seem to find an
    > answer to it. I'm building up a new road bike with triple
    front/9 rear
    > gearing. Are there any combinations of gears that are
    either impossible, or
    > at least unrecommended due to excessive chain flex,
    derailleur rub or wear,
    > chainstay rub, etc.? I know that on my old 2x7 road bike
    the extreme
    > combinations were effectively unusable, but I'm wondering
    how this works
    > with a 3x9.
    >
    > Also, does it make a difference as to which make and model
    of cranks,
    > cassette, chain and derailleurs one uses? I'm most likely
    going to go with
    > Shimano Ultergras, but there's a chance I'll go with Campy
    Chorus or
    > Centaur.
    >
    > If there are online resources that answer this sort of
    question, that would
    > be great too.
    >
    Stay away from extremes - big/big and small/small - you may be able to use them if your bike is set
    up properly, but not recommended because of increased wear.

    Shimano nine speed triples have a 'trim' position between granny and middle, so you can use
    pretty well the whole range in the middle ring, and all but one or two of the small sprockets in
    the granny.

    Don't know a lot about Campagnolo, but I believe the front shifter provides multiple trim positions.
     
  5. armchair_spacem

    armchair_spacem New Member

    Joined:
    Oct 19, 2003
    Messages:
    141
    Likes Received:
    0
    There's an excellent gear-inch and shifting pattern calculator at http://www.panix.com/~jbarrm/cycal/cycal.30f.html
    which will show you your best progression through your ratios, particularly where there's overlap or very small difference between ratios. I understand the extremes where ahain is "crossed" are a bit more pronounced with a triple and are to be avoided.


     
  6. Kovie

    Kovie Guest

    Thanks, but I've already written such a calculator for myself with MS Excel. All I really wanted to
    know was which combos were to be avoided, not which combos were available.

    --
    Kovie [email protected]

    "armchair_spacem" <[email protected]> wrote in message
    news:[email protected]...
    > Kovie wrote:
    > > I'm sure that this is a very common question but I can't seem to find
    an
    > > answer to it. I'm building up a new road bike with triple front/9 rear gearing. Are there any
    > > combinations of gears that are either
    impossible,
    > > or at least unrecommended due to excessive chain flex, derailleur rub
    or
    > > wear, chainstay rub, etc.? I know that on my old 2x7 road bike the extreme combinations were
    > > effectively unusable, but I'm wondering how this works with a 3x9. Also, does it make a
    > > difference as to which make and model of cranks, cassette, chain and derailleurs one uses? I'm
    > > most likely going to go with Shimano Ultergras, but there's a chance I'll go with Campy Chorus
    > > or Centaur. If there are online resources that answer this sort of question, that would be
    > > great too. Thanks!
    > > --
    > > Kovie [email protected]
    >
    > There's an excellent gear-inch and shifting pattern calculator at
    > http://www.panix.com/~jbarrm/cycal/cycal.30f.html which will show you your best progression
    > through your ratios, particularly where there's overlap or very small difference between ratios. I
    > understand the extremes where ahain is "crossed" are a bit more pronounced with a triple and are
    > to be avoided.
    >
    >
    >
    >
    >
    > --
    > >--------------------------<
    > Posted via cyclingforums.com http://www.cyclingforums.com
     
  7. boudreaux

    boudreaux New Member

    Joined:
    Oct 16, 2003
    Messages:
    5,133
    Likes Received:
    0
    Given trim positions in the front shifter, and chainstays that aren't too short, all combinations could be usable.However you should not be in the samll/small or big/big, and as the granny ring is often considered a bailout there is really little need for several of the smallest cogs when in the granny. it does not maatter which brand you use,but stick with one manufacturer, although cranksets can be interchanged with the appropriate BB. I prefer Campy triple shifting as it uses a fine ratchet on the front shifter which allows more derailer trim and is less critical of adjustment than the shimano index system.
     
  8. Pete Biggs

    Pete Biggs Guest

    Kovie wrote:
    > All I really wanted to know was which combos were to be avoided, not which combos were available.

    Depends on angle of chain - which depends on bike, chain stay length, bottom bracket, cranks,
    wheels, etc - and on how much you dislike the friction the "bad" gears cause.

    On my 9sp road triples, I tend to avoid:

    - inner chainring with smallest 4 rear cogs
    - middle with largest and smallest cogs (for long)
    - outer with largest 3 or 4 cogs

    ~PB
     
  9. Kovie

    Kovie Guest

    Thanks. I'm leaning towards making is as all-Campy as possible, but my Shimano-compatible wheels
    (Mavic Cosmos) require either a Shimano cassette, or a Shimano-Campy conversion cassette. None of
    this should affect your advice, though, I assume.

    --
    Kovie [email protected]

    "boudreaux" <[email protected]> wrote in message
    news:[email protected]...
    > Kovie wrote:
    > > I'm sure that this is a very common question but I can't seem to find
    an
    > > answer to it. I'm building up a new road bike with triple front/9 rear gearing. Are there any
    > > combinations of gears that are either
    impossible,
    > > or at least unrecommended due to excessive chain flex, derailleur rub
    or
    > > wear, chainstay rub, etc.? I know that on my old 2x7 road bike the extreme combinations were
    > > effectively unusable, but I'm wondering how this works with a 3x9. Also, does it make a
    > > difference as to which make and model of cranks, cassette, chain and derailleurs one uses? I'm
    > > most likely going to go with Shimano Ultergras, but there's a chance I'll go with Campy Chorus
    > > or Centaur. If there are online resources that answer this sort of question, that would be
    > > great too. Thanks!
    > > --
    > > Kovie [email protected]
    >
    > Given trim positions in the front shifter, and chainstays that aren't too short, all combinations
    > could be usable.However you should not be in the samll/small or big/big, and as the granny ring
    > is often considered a bailout there is really little need for several of the smallest cogs when
    > in the granny. it does not maatter which brand you use,but stick with one manufacturer, although
    > cranksets can be interchanged with the appropriate BB. I prefer Campy triple shifting as it uses
    > a fine ratchet on the front shifter which allows more derailer trim and is less critical of
    > adjustment than the shimano index system.
    >
    >
    >
    > --
    > >--------------------------<
    > Posted via cyclingforums.com http://www.cyclingforums.com
     
Loading...
Thread Status:
Not open for further replies.
Loading...