Pitch

Discussion in 'Road Cycling' started by Neil Smith, Feb 25, 2004.

  1. Neil Smith

    Neil Smith Guest

    Need new rings, how do you measure the pitch on a chainset? Thanks
     
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  2. On Wed, 25 Feb 2004 17:35:55 -0000, "Neil Smith" <[email protected]>
    wrote:

    >Need new rings, how do you measure the pitch on a chainset? Thanks
    >

    how old is the bike?
     
  3. Terry Morse

    Terry Morse Guest

  4. On Wed, 25 Feb 2004 10:00:08 -0800, Terry Morse <[email protected]>
    wrote:

    >Neil Smith wrote:
    >
    >> Need new rings, how do you measure the pitch on a chainset?
    >
    >Sheldon Brown has a conversion table. You measure distance between adjacent bolts, the table gives
    >you bolt circle diameter:
    >
    >http://www.sheldonbrown.com/gloss_bo-z.html

    ah! I thought he was talking about the pitch of the chain! Aren't all chains (at least in the last,
    er, 40 years?) the same pitch (length of links)?
     
  5. Neil Smith

    Neil Smith Guest

  6. Chalo

    Chalo Guest

    "Neil Smith" <[email protected]> wrote:

    > Need new rings, how do you measure the pitch on a chainset?

    Chain pitch is simply the distance between adjacent pins in the chain. All modern bikes use 1/2"
    pitch; a few antiques use special 1" pitch chain that is not interchangeable with 1" pitch
    industrial chain.

    Any rings that you can buy off the shelf will be 1/2" pitch. They are distinguished only by their
    tooth width, with single-speed equipment traditionally using 1/8" width and derailleur bikes using
    3/32" width. Industrial 1/2" pitch chain is designed for 1/4" wide teeth.

    Chalo Colina
     
  7. Neil Smith

    Neil Smith Guest

    Thanks for the informative reply. The bike shop having trouble selecting
    replacement rings for my chainset and they were talking "Pitch". How do you
    establish which type of ring is required for a particular chain ring. The
    old one, I suspect very old is Suigino Comp super-shifter. Would anyone how
    to find the size by which I could find something similar? Also I am thinking
    of going for a larger large ring, moving up from 48 to 50 or 52. What will
    be the sizes for the other two rings. I believe that I will have to adjust
    the front derailleur. How to I determine, apart from the hard way, the
    correct position?
    Thanks
    "Chalo" <[email protected]> wrote in message
    news:[email protected]...
    > "Neil Smith" <[email protected]> wrote:
    >
    > > Need new rings, how do you measure the pitch on a chainset?
    >
    > Chain pitch is simply the distance between adjacent pins in the chain. All modern bikes use 1/2"
    > pitch; a few antiques use special 1" pitch chain that is not interchangeable with 1" pitch
    > industrial chain.
    >
    > Any rings that you can buy off the shelf will be 1/2" pitch. They are distinguished only by their
    > tooth width, with single-speed equipment traditionally using 1/8" width and derailleur bikes using
    > 3/32" width. Industrial 1/2" pitch chain is designed for 1/4" wide teeth.
    >
    > Chalo Colina
     
  8. Chalo

    Chalo Guest

    "Neil Smith" <[email protected]> wrote:

    > How do you establish which type of ring is required for a particular chain ring. The old one, I
    > suspect very old is Suigino Comp super-shifter. Would anyone how to find the size by which I could
    > find something similar?

    You're going to have to clarify what you mean by "ring" in the first instance.

    > Also I am thinking of going for a larger large ring, moving up from 48 to 50 or 52. What will be
    > the sizes for the other two rings.

    You can probably make a change of 2-4 teeth on the big ring without replacing the other rings. If
    you intend to replace them anyway, the best thing to do from a front derailleur standpoint is to
    maintain the same intervals between rings, e.g 28-38-48 -> 30-40-50 or 32-42-52. However, I have
    never had a problem using a larger big ring, and the ratio between a 28 and a 38 is the same as
    between a 38 and a 52. I think it's nice to have the same size step between successive rings.

    > I believe that I will have to adjust the front derailleur. How to I determine, apart from the hard
    > way, the correct position?

    Yes, you'll have to move it upwards along the seat tube to clear the larger ring. Detach the cable
    first. With an older front derailleur that has a mostly flat outer cage, just set the derailleur so
    that the outer plate is parallel to the big ring, and so that it clears the teeth on the big ring by
    about 1.5mm when it is swung through its motion. Verify that your limit stops are set appropriately,
    and reattach the cable.

    Chalo Colina
     
  9. The're all the same: 1/2 inch pitch. It's one of the few things on a bicycle that stubbornly refuses
    to go metric. Why they can't change it to, say 12 mm, I don't know.

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

    Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

    Chris'Z Corner http://www.geocities.com/czcorner
     
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