Forum home Road cycling forum Workshop

Seat Post Clamp Size

AndsAnds Posts: 1,437
edited September 2010 in Workshop
My seat post clamp has sheared and I'm a bit confused by sizing.

The seat post is 27.2mm but the clamp is ~32mm diameter. I'm not too sure whether I need to use the post diameter or the clamp diameter when ordering a new one. (Looked at one on Wiggle and the available sizes are 28.6, 29.8, 31.8, 34.9 and I've got no idea which is the one I need). Thanks

Posts

  • The clamp diameter shpould be somewhere on the tubing

    ANyhoo seat tubes tend to come in three standard outside diameters : 28.6 mm, 31.8 mm and 34.9 mm

    for a 27.2 my one uses a 31.8 clamp.
    The dissenter is every human being at those moments of his life when he resigns
    momentarily from the herd and thinks for himself.
  • cooldadcooldad Posts: 32,601
    The clamp diameter shpould be somewhere on the tubing

    ANyhoo seat tubes tend to come in three standard outside diameters : 28.6 mm, 31.8 mm and 34.9 mm

    for a 27.2 my one uses a 31.8 clamp.

    Which is as near to 32mm as you will be able to measure.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • It might even say what size it is on the inside of the existing clamp - or somewhere on it.
  • AndsAnds Posts: 1,437
    OK, thanks, all sorted - bought a 31.8. There wasn't anything printed on either the existing clamp or frame.

    The seatpost on my other bike is 31.6mm and I'd got a bit mixed up with that and the 31.8mm sizes when looking at clamps. All makes sense now!
Sign In or Register to comment.