Siezed Alloy Seatpost – Carbon Frame. Now out but....

Funkyfreddy1 Posts: 32
edited December 2011 in Workshop
Howdo all

End of August I picked up a BeOne Pearl Comp from CRC – it seemed an attractive option within the budget I had set myself to replace my (still in the garage, but hope to get roadworthy again) Carlton Criterium.

The other night after riding home I decided I was wanted to try an adjustment to the seatpost – wouldn't budge !

Although its a bog standard alloy post I wasn't expecting a problem in a carbon frame even less so after such a short time. Quick look online and I see a few with similar problems.

Anyway, managed to get the post out this evening – not sure if Plus Gas actually did any good as I'm not sure it penetrated that far down the tube but that with a little warm air may have helped in freeing things up enough for me to get it out.

The front half is pretty much as new whilst the back half is a different matter !

A few pictures below:

I'm puzzled what might have caused the problem though – moisture or just some chemical reaction between the carbon frame and alloy post ? I have been out when it has been wet but not that often or for too long but could spray have been the culprit ? I had decided earlier in the week to look at ordering some Crud Roadracer's or SKS Race Blades - perhaps they will help in future ?

Could anybody advise best way to clean down the inside of the frame without harm ?

I'll look at a new post but on the one hand I hear “No Grease” when fitting yet there seems to be some compounds available that suggest they could be of benefit ?

I guess regular preventative maintenance/cleaning would be the best answer ?

Any help/input very much appreciated.

Bes Rgds


  • Monty Dog
    Monty Dog Posts: 20,614
    The corrosion is created by a galvanic reaction between the alloy post and the crabon frame, aided by the water running down the post from the rear wheel. To clean out the frame get your LBS to run a reamer down the seattube as the oxide residue build-up reduces the diameter.Install a new post with a anti-seize paste or even grease.
    Make mine an Italian, with Campagnolo on the side..
  • Thanks for the reply Monty.

    I'll get the tube sorted.

    As for the replacement - would I be correct in hoping carbon - carbon would help reduce the risk of galvanic corrosion in the future ?

  • Monty Dog
    Monty Dog Posts: 20,614
    Worth checking to see that there isn't an aluminium sleeve in the seattube - many carbon frames do. Use a carbon assembly paste regardless
    Make mine an Italian, with Campagnolo on the side..
  • Monty Dog
    Monty Dog Posts: 20,614
    Should have added, a Flex Hone down the seattube should remove the oxide build up
    Make mine an Italian, with Campagnolo on the side..