Seat post for carbon framed bike

pcaley Posts: 9
edited September 2013 in Road buying advice
I am thinking of buying a Cube Agree GTC Pro, and it will come with a 31.6mm dia seat post. I see that Cannondale Synapses come with a 27.2mm dia post apparently for extra cushioning. Anybody got knowledge of if the smaller dia post is noticably better? Can you buy a sleeve that will allow fitment of a 27.2 post to the cube?


  • Shims are available. I sell the cane creek shims but their is much choice out there. Go for a long shim though.

    27.2mm post are lighter and less stiff which is the point. 31.6mm posts are used on large diameter seat tubes which are used to increase frame stiffness. You could just fit wider tyres or drop tyre pressue though for bigger change. -wheel building and other stuff.
  • ^^ Is good advice re: tyres etc.

    Also worth considering is a Syntace P6 carbon post - these are available in a 31.6, and are designed for some flex etc.

    Reviewed on this site here:
    Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS
  • me-109
    me-109 Posts: 1,915
    My Scott specifically states not to use a shim in the seat tube. Don't know why, but if you are at all worried about warranty claims, may be worth checking before forging ahead. Alternatively, stick with the intended size. I thought there was slightly less buzz with a carbon post (same size as the alu one).
  • smidsy
    smidsy Posts: 5,273
    I have a CAAD with a 27.2 and a Carbon Basso with a 31.6 and IME there is no loss of comfort.

    Shims are available but it will look like a dogs dinner with the thin post eminating from a thick tube.
    Yellow is the new Black.
  • How much seat post exposed could also affect this
    I'm sorry you don't believe in miracles
  • defride
    defride Posts: 277
    My 2013 GTC Race is 27.2 as is the 2014 Pro, I'd be surprised if the 2013 Pro wasn't also 27.2