27mm seatposts

Discussion in 'UK and Europe' started by Ian G Batten, Jun 6, 2004.

  1. Ian G Batten

    Ian G Batten Guest

    My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    And it presumably is: a 27.2mm seatpost I have around won't fit, so
    unless both are mislabelled it's consistent.

    I'd like a more rigid seatpost, as it appears to flex somewhat if the
    suspension is locked out. But 27.0mm seatposts are thin on the ground.
    Thompson's layback post, for example, starts at 27.2mm. Any thoughts?

    ian
     
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  2. Tony Raven

    Tony Raven Guest

    Ian G Batten wrote:
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the ground.
    > Thompson's layback post, for example, starts at 27.2mm. Any thoughts?
    >
    > ian


    There seem to be quite a few on Wiggle. The Titec is fairly stiff and a
    reasonable price. Otherwise there are plenty of more expensive ones. Several
    (X-Lite, Use etc) use a shim system to fit.

    Tony
     
  3. Simon Brooke

    Simon Brooke Guest

    in message <[email protected]>, Ian G Batten
    ('[email protected]') wrote:

    >
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the
    > ground.
    > Thompson's layback post, for example, starts at 27.2mm. Any thoughts?


    I have a spare Ritchey 27.2 with slight layback which came on my
    Cannondale. It's spare because in my opinion it's of equivalent worth
    to a fetid pile of steaming dingos kidneys; the one-bolt design tends
    to slip when you go down steep rocky bits leaving you with a saddle
    pointed God knows where, which is decidedly uncomfortable. I replaced
    it with a BBB two bolt post which was cheap and is very good - I have a
    similar (but much larger diameter) BBB post on my Mantra.

    I have to admit I'm surprised at Cannondale and Marin using such small
    diameter seatposts because as you say they do flex. Having said that
    I'm pleased with my BBBs - they aren't the lightest things around but I
    haven't noticed the flex problem so much.

    --
    [email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/
    .::;===r==\
    / /___||___\____
    //==\- ||- | /__\( MS Windows IS an operating environment.
    //____\__||___|_// \|: C++ IS an object oriented programming language.
    \__/ ~~~~~~~~~ \__/ Citroen 2cv6 IS a four door family saloon.
     
  4. Mark

    Mark Guest

    Hi Ian, I have on occasion seen a few 27.0mm Campagnolo Record
    Aluminum Seatposts show up on ebay. Some of these are quite sturdy,
    some have fluted posts, and I doubt if you would get any flex with
    these, yet still retain very light weight.

    There is one seller who is in Germany (Cyclo network), who constantly
    comes up with stuff like this. Perhaps try a search? Hope this idea
    helps, Mark

    Ian G Batten <[email protected]> wrote in message news:<[email protected]>...
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the ground.
    > Thompson's layback post, for example, starts at 27.2mm. Any thoughts?
    >
    > ian
     
  5. dan baker

    dan baker Guest

    Ian G Batten <[email protected]> wrote in message news:<[email protected]>...
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit,

    ---------------

    If you want to try using the 27.2 you have.... .2mm isn't "too" hard
    to remove with some sandpaper and elbow grease. Takes a while, and
    you'll get nasty black Al everywhere, but its possible.

    d
     
  6. SDMike

    SDMike Guest

    "Ian G Batten" <[email protected]> wrote in message
    news:[email protected]
    >
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the ground.
    > Thompson's layback post, for example, starts at 27.2mm. Any thoughts?
    >
    > ian


    Have you checked ebay?

    I have a 27.0mm Superbe Pro seatpost. I know if I have one, they had to make
    more... Check for XC Pro too. Same basic SP, just longer.

    M
     
  7. If I were to need one, not finding a scrap one I would do this.
    I would take a Campagnolo two-bolt 27.2mm post and reduce it to 27.0.
    No need to have a lathe. A belt sander is enough, and quite appropriate.

    Also, it can be done by a metal polishing shop.
    Here, the inconvenience is that the seatpost gets very hot when being
    polished; due to thermal expansion of the aluminum alloy, it is not so
    easy to confidently measure the diameter while doing the job.

    Sergio
    Pisa
     
  8. Matt O'Toole

    Matt O'Toole Guest

    Ian G Batten wrote:

    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the
    > ground. Thompson's layback post, for example, starts at 27.2mm. Any
    > thoughts?


    27.0 was a common size for mountain bikes in the early 90s. I'm pretty sure
    that's what my Diamond Back had, and they made tons of those. So there's bound
    to be a healthy supply of these posts somewhere. You might try Hokie Spokes
    here in Blacksburg -- they have a whole wall of bins with nothing but seatposts.
    Tell Dave I sent you -- www.hokiespokes.com for the phone number.

    Matt O.
     
  9. Matt O'Toole wrote:

    > Ian G Batten wrote:
    >
    >
    >>My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    >>And it presumably is: a 27.2mm seatpost I have around won't fit, so
    >>unless both are mislabelled it's consistent.
    >>
    >>I'd like a more rigid seatpost, as it appears to flex somewhat if the
    >>suspension is locked out. But 27.0mm seatposts are thin on the
    >>ground. Thompson's layback post, for example, starts at 27.2mm. Any
    >>thoughts?


    Google can find 'em : http://tinyurl.com/34hvk

    ** Phil.
     
  10. "Matt O'Toole" <[email protected]> wrote:

    > 27.0 was a common size for mountain bikes in the early 90s.


    It continued to be a common size for steel mountain bikes with 28.6mm seat
    tubes while steel mountain bikes remained common. Most steel Konas, for
    example, many steel Marins, the earlier steel Stumpjumpers and Rockhoppers.
    It's still one of the most widely available sizes, though not as common as
    27.2

    > So there's bound to be a healthy supply of these posts somewhere.
    > You might try Hokie Spokes here in Blacksburg -- they have a whole
    > wall of bins with nothing but seatposts.


    and Phil Brown had written:

    > Your LBS can get 27.0 Campy posts from Euro Asia


    The uk.rec.cycling crosspost, Ian's EU e-mail address and British ISP
    suggests that a North American dealer may not be the most convenient.

    James Thomson
     
  11. "Ian G Batten" <[email protected]> wrote:

    > I'd like a more rigid seatpost, as it appears to flex somewhat
    > if the suspension is locked out. But 27.0mm seatposts are
    > thin on the ground.


    Perhaps not quite as common as 27.2, but certainly among the most common
    sizes.

    > Thompson's


    Thomson's

    > layback post, for example, starts at 27.2mm. Any thoughts?


    If you really find flex a problem, bear in mind that the materials used in
    most of the posts on the market have about the same specific stiffness, are
    simple cylindrical plain-gauge extrusions, and can only therefore be
    stiffer than your OEM post if they're also heavier. Expensive posts using
    stronger alloys generally do so in order to allow thinner tube walls to be
    used, reducing weight, but also reducing stiffness unless the weight is
    redistributed to the areas of greatest stress. Thomson and Ritchey use an
    oval bore, increasing fore-aft stiffness at a given weight. A Ritchey Comp
    is quite cheap, as stiff as anything else you can buy, has a little
    layback, and is widely available in the UK. The KAlloy model, made in the
    same factory, is a little heavier, cheaper, but just as stiff.

    You might keep an eye on eBay for an old steel Shimano XT or DX post -
    there's an unused one on eBay.de right now [item 3680550946]. It never
    hurts to ask if the seller will ship to the UK.

    Using a shimmed post would be a waste of money, as reducing the diameter is
    a great way to reduce stiffness unless the tube walls are also beefed up
    out of proportion.

    Having said all that, I'm heavy, and my two hardtails both use long 27.0mm
    posts (a light Syncros, and a Ritchey Comp). I wonder how much your
    seatpost can really be flexing unless your rear end is also taking more of
    a battering than is good for it.

    James Thomson
     
  12. Ian G Batten <[email protected]> wrote in message news:<[email protected]>...
    > My 2004 Mount Vision has an unbranded seatpost that is marked 27.0mm.
    > And it presumably is: a 27.2mm seatpost I have around won't fit, so
    > unless both are mislabelled it's consistent.
    >
    > I'd like a more rigid seatpost, as it appears to flex somewhat if the
    > suspension is locked out. But 27.0mm seatposts are thin on the ground.
    > Thompson's layback post, for example, starts at 27.2mm. Any thoughts?
    >
    > ian


    I got one here last month for $10:

    http://www.theped.com/blowout.htm right side, almost all the way to the bottom:

    >27.2 Ritchey road seat post $14.95 fits M2 and A1 road and many other high
    >quality frames, 250mm, silver. OEM (Original Equipment for Manufacturers)


    It says 27.2 but they have many sizes including 26.8 and 27.0 in silver and black.

    -Doug
     
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