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A bad start

NotnormalNotnormal Posts: 132
edited February 2009 in MTB workshop & tech
Bits for my first bike build have slowly been arriving from ebay and various other sources and I thought I'd put the first few together today. I'm a TOTAL beginner and its not been a great start. My nice Easton carbon seatpost was connected to the saddle with no dramas until I tried to fit the seatpost to the frame. Its a 27.2mm seatpost which is definitely the correct size. I had previously fitted a 31.8mm seatpost clamp to the frame which I slackened right off. The post was very very tight inserting it into the frame.

Once in I was unable to tighten the QR seatpost clamp as it was too tight. I slackened it off so much that when I applied the QR it only had the first couple of threads engaged and I cross threaded it in my ham fisted attempt to get it to close. My initial thoughts are that the new frame sat for a week or so with the seatpost clamp on (not tightened) has caused the frame to be a tight fit for the seatpost and is causing the rest of the problems. I've taken the bolt of the clamp right off and have put the seat post in as low as it will go to hope that loosens off the frame in some way.

Excuse my poor use of english in trying to explain its hard to get it across in words. Anyone got any pointers before I heqad to the LBS in shame after falling at the first hurdle!


  • supersonicsupersonic Posts: 82,708 Lives Here
    Sometimes the edge of tolerances can cause very tight or loose fits. You may need the tube reaming so it fits.
  • Also I've just noticed that as the seatpost is 2nd hand, from the markings on it it must have previously been installed in a rear facing seat tube which seems to have 'squared' off the post to a small degree. My seattube is front facing. Could this be effecting things?
  • supersonicsupersonic Posts: 82,708 Lives Here
    No, not really. Is the tube smooth though, no bumps? And the top of the seat tube clamp area not distorted ie perfectly round?

    I'd visit the LBS and try another post.
  • Thanks for the replies. From a bit of messing around with different length bolts its in and fitting ok. I've adapted a QR seat clamp to be a bolt through, its not pretty but its working which is the main thing and I can tidy it up a bit later.
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