Stopping a slippery seat post - help!

sad_muso
sad_muso Posts: 16
edited December 2014 in Workshop
Hi All,

I've recently done up an early 90s racer and everything was spot on until the original seat post broke. It was a 27.2 so I went to Halfords and their own 27.2 in stock didn't fit; my frame was too tight. They ordered in a different 27.7 and a 27.0 and again the 27.2 was too tight so I settled for the 27.0 as it felt as though it tightened up well...

...that was until I gave it a 15 minute test ride, only to find that it was slipping. I presume that the frame hole is either a weird old size/has worn or something, but can anyone please suggest the best way to resolve this? I imagine that their must be either an adhesive film I can wrap round the seat post or perhaps an alternative clamp?

Any ideas greatly appreciated! :)

Thanks

sad muso

Comments

  • bill57
    bill57 Posts: 454
    In the past I have spray painted a seatpost to add some thickness, that worked OK. Clearly this would not work if the seatpost is actually loose.

    More recently I have been curious about this stuff, and plan to give it a try at some point.............

    http://www.creasingmatrix.com/index.php ... tape-plus/
  • ai_1
    ai_1 Posts: 3,060
    Have you tried assembly paste?
  • jermas
    jermas Posts: 484
    If the original seatpost was 27.2 and fitted, then I'd try to replace it with a 27.2 that fits. Have you tried measuring (verniers) both 27.2 seatposts to see if they're actually the correct size ? Also give the seat tube on the frame a very good clean to remove any corrosion. Spring the opening (where the clamp fits) out v slightly using the old seatpost.
    Finally try greasing the seatpost before you insert it- it'll slide much easier in the frame and stop future seizing/corrosion.
  • de_sisti
    de_sisti Posts: 1,283
    Jubilee clip on seat post, carbon paste and a slightly longer seat clamp bolt (solved the problem that I had on my steel frame).
  • If it's a 27.2 internal diameter then you really need to use that size post. Possibly there's corrosion in the tube that's preventing the post fitting correctly.

    A Local Bike Shop should be able to ream out the seat tube with a 27.2 reamer. It's a simple job with the right tool.