Seat post slipping

pottssteve Posts: 4,069
edited April 2016 in Workshop
Hi Guys,

Looking for a bit of advice. My seat post has started to slip when I am riding, despite the collar being good and tight. It's a carbon-wrapped post in a titanium frame. Any advice on stopping slipping would be appreciated, as I can only find info on carbon frames.

Head Hands Heart Lungs Legs


  • ayjaycee
    ayjaycee Posts: 1,277
    I would think that you need to take out the post, clean it (and inside the frame), apply some carbon assembly paste and put it all back together again. You will need to check on what torque to tighten to as the carbon could be susceptible to damage if over-tightened. The downside is that the carbon paste is very expensive for something that you would use infrequently and a tube will probably outlast you!
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  • keef66
    keef66 Posts: 13,123
    ^ wot he said. My first proper road bike had a carbon post in an alloy frame. Post would slip down gradually despite proper tightening. Now with a dollop of carbon paste it stays rock solid without having to tighten it very much at all. I take it out and give it a wipe down / reapply the paste every 6-8 months, just to guard against corrosion / ensure it's not stuck in there.
    Ditto with the newer carbon framed bike with an alloy seatpost too.
  • marcusjb
    marcusjb Posts: 2,412
    ^all of that for sure.

    Is it a new post?

    Try another post temporarily as well - it is rare, but you do get posts that are slightly too much under their nominal diameter. Or, even worse (and it happened to me in 2011) a frame that is slightly over the diameter (and it was only tenths of a mm in it, but was enough to cause slipping).
  • pottssteve
    pottssteve Posts: 4,069
    Many thanks for the advice, guys. It's not a new post, but just seems to have developed the problem over the last couple of weeks. Looks like it's a clean and some carbon paste, then.

    Head Hands Heart Lungs Legs
  • jermas
    jermas Posts: 484
    You can get double clamps like these This type hold really well - great on a carbon bike where the torque setting is really low > 5nm.
  • relk
    relk Posts: 21
    For carbon posts you should use carbon paste. It's a grayish paste that you put on the contact points and that shoudl do the trick. Mechanics use it and it's made for that purpose.
  • hsiaolc
    hsiaolc Posts: 492
    I've had that problem before.

    Like a few said use carbon paste. However, it wasn't enough for me either.

    Best just go clamp another clamp on top and that will stop from slipping completely. Also I changed to a better clamp.

    So all three stops my seat from falling and I am 98kg.
  • pottssteve
    pottssteve Posts: 4,069
    Hi All,

    I thought I'd share the solution, as it might be useful to someone. I tried carbon paste and it was still slipping a little. Spoke to a couple of people and one suggested using a Coke can. I cut a small square out of an aluminium can and slid it in with the seat post. Re-tightened the collar and it seems to be holding OK.

    Head Hands Heart Lungs Legs