Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Senior Member
    Join Date
    Jul 2006
    Posts
    116
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    How unlikely is it that a 27.2mm seatpost will fit in a bike that has a 27mm seatpost

    at the moment?


    Totally skint and I need a new seatpost. There seems to be a decent 27.2mm one in a sale, but it appears that according to my bike's spec online somewhere it currently has a 27.2 mm diameter seatpost. Should I just forget it and pay the extra or is .2 of a mm not much and it might fit anyway?

    Cheers
    ** wishes I was 'zac fit' **

  2. #2
    AEO
    AEO is offline
    Senior Member AEO's Avatar
    Join Date
    Jun 2007
    Location
    A Coffin Called Earth. or Toronto, ON
    My Bikes
    Bianchi, Miyata, Dahon, Rossin
    Posts
    12,254
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    you can take some sand paper to the seatpost and shave off that extra 0.2mm in no time.

    wear a mask, aluminum dust is toxic if inhaled
    Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
    http://sanfrancisco.ibtimes.com/arti...ger-photos.htm

  3. #3
    Real Men Ride Ordinaries fuzz2050's Avatar
    Join Date
    Sep 2008
    Posts
    3,681
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by AEO View Post
    you can take some sand paper to the seatpost and shave off that extra 0.2mm in no time.

    wear a mask, aluminum dust is toxic if inhaled
    of course, then you have to factor in how much the sand-paper and mask cost. Not to mention your time

  4. #4
    me have long head tube TallRider's Avatar
    Join Date
    Oct 2005
    Location
    Chapel Hill, NC
    Posts
    4,103
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    get a 27.0mm - they're cheap enough. I don't think it's worth mucking around with sandpaper unless you have a seatpost that's a weird size and hard-to-find, or very expensive. Or if you wanted to fit a suspension seatpost (probably only available in really common sizes) into a less-common-sized seat tube.

    I happen to have two sitting around (one road-length from the 80's, one mtb-length from the late 90's) if you want one of mine. Probably no more - and maybe less - than buying a new 27.2 on sale, whether you buy a used 27.0 from me or someone else.

  5. #5
    Guest
    Join Date
    Jul 2008
    Location
    Grid Reference, SK
    My Bikes
    I never learned to ride a bike. It is my deepest shame.
    Posts
    3,769
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    How unlikely is it that a 27.2mm seatpost will fit in a bike that has a 27mm seatpost
    I'd say about 99% unlikely, unless you modify it as mentioned above. If you already have mismatched brakepads and popcan-shims holding your stem and bars in, or you have three different colours of rusty cable housing and both your tires have multiple duct tape repairs (in short: if the bike is a total beater), then go for it

    Many seatposts are available in smaller sizes - like 25.4 - and you can use a shim to make them fit properly. And 25.4 seatposts can be very very very cheap - that size is regularily used on some of the cheapest bikes around. But even a reasonable quality aluminum seatpost from a shop in the correct size is going to be less than $20. A used bike shop or co-op might have something very cheap.

  6. #6
    Senior Member
    Join Date
    May 2005
    Location
    Terre Haute, Lafayette, or Indianapolis, IN, depending on the day
    My Bikes
    n, I would like n+1
    Posts
    1,917
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Unless you shave the post (0.2mm takes longer than you think unless you have a lathe), which probably won't be very uniform, it's never going to fit. If you get it in without modification, you'll probably seize the post in the frame. Last time I needed a post in an odd size I asked my local shop to order the cheapest aluminum post they could find (likely Kalloy or such). It cost me ~$12, and while it's a bit heavy, it turns out it isn't slowing me down any.

  7. #7
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    27,965
    Mentioned
    165 Post(s)
    Tagged
    1 Thread(s)
    If you're sure that 27.0 is the correct size, there's no way the 27.2 will fit.

    BTW- I have a few new old stock 27.0 posts of various qualities in stock. If you're interested, PM me with your target price range and I'll make you an offer.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  8. #8
    New Orleans
    Join Date
    Jan 2006
    Posts
    2,571
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    I've ground down a seatpost 0.2mm and it takes a LONG TIME-LOTTA WORK WITH A HAND HELD MECHANICAL SANDER. I think it took about 1 hour of grind, test, grind test etc, and it looked cheesy at the end. It was a long-maybe 350mm-seatpost, but I probably just did about 7"-175mm- of it.

    Pay the extra $$
    Charlie

  9. #9
    DRF aka Thrifty Bill wrk101's Avatar
    Join Date
    Jan 2008
    Location
    The NC Mountains
    My Bikes
    86 Katakura Silk, 87 Prologue, 87 Cimarron, 14 frame school custom, 73 Paramount
    Posts
    19,986
    Mentioned
    141 Post(s)
    Tagged
    1 Thread(s)
    Forcing in a larger seat post is a dumb idea. Seat posts are cheap.

  10. #10
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,306
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TallRider View Post
    get a 27.0mm - they're cheap enough.
    +1

    Standard AL post will be about $10-$15.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  11. #11
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Haha, I started a thread about this very issue a few years ago. My solution: use a lathe to machine off .2mm from the OD. Problem solved

    .2mm is only about .008", or the thickness of two sheets of printer paper.
    C://dos
    C://dos.run
    run.dos.run

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •