I have an aluminum bicycle seat tube stuck in a steel frame. I have been using penetrating oils and heat and hammering and such to loosen the corrosion. Now I drilled a hole in the seat post, and can insert a metal rod.

How do I grip the rod with good leverage to turn out the seat post? Thanks for any advice. I don't have a socket extension, so I'm showing the image below with a screwdriver. I have an adjustable end wrench (25cm), but nothing bigger. I could rent something if necessary. So far, I can't turn it. Thanks for any advice!

seat post


  • 3
    I’m voting to close this question because it has nothing to do with Home Improvement. – Daniel Griscom Sep 5 '20 at 11:07
  • I'm new here. Is there another community that would be a better fit? – Cameron Brick Sep 5 '20 at 11:08
  • 2
    How about bicycles.stackexchange.com? – Daniel Griscom Sep 5 '20 at 11:47
  • yes, makes sense. I find the tags in this community a closer fit to this specific question—how to accomplish leverage on a corroded metal connection—but I agree it is a bicycle part being leveraged. – Cameron Brick Sep 5 '20 at 11:54
  • Have you tried hitting the screwdriver with a hammer on each side of the pipe in the direction of the seat? – JACK Sep 5 '20 at 12:09

This, unfortunately, is a common and difficult problem. The issue is corrosion between the Aluminum and Steel and it can make it difficult and sometimes impossible to separate them.

Here is an article from Sheldon Brown that describes some causes, prevention, and fixes:

Sheldon Brown Seatpost Article

I suggestion trying #9 to start with.

  • Good resource: I did read that and several other long threads on the topic. I haven't tried ammonia yet. – Cameron Brick Sep 5 '20 at 10:50
  • Keep in mind, however, that in some cases the two parts cannot be separated without ruining the bicycle's seat tube. Good luck! – jwh20 Sep 5 '20 at 11:04
  • Agreed, and that's fine in this case. Hoping not to damage the frame, but that's possible also. This particular seat tube ends in a suspension mechanism, and previous liquids I've poured in the frame came out that mechanism (slowly). So now I'm wondering how I might block the inside of the seat tube so the ammonia doesn't flow through. Maybe a balloon? – Cameron Brick Sep 5 '20 at 11:07
  • I blocked the inside of the seat tube so the ammonia doesn't flow through with an inflated latex glove. – Cameron Brick Sep 5 '20 at 11:53
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    @CameronBrick slow down - approach this methodically or you'll risk ruining the bottom bracket and bearings too. Try chat.stackexchange.com/rooms/214/the-velodrome where this is on-topic. – Criggie Sep 11 '20 at 5:05

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