Our head mechanic has had success with soaking seat-posts with Coca Cola (frame upside down; plug the end of seatpost if it’s a straight post; you might have to remove the bottom-bracket for this or if the frame has water-bottle bosses on the seat tube you can inject/ pour thru those).  This takes time but works on frames where the post is seized in the frame due to metals reacting with eachother and not rust.  Don’t use this with carbon, only aluminum/ steel frames.  Also, using ammonia is another trick but beware that it can cause aluminum to expand, so you need to understand your metals (steel frame? Steel post?).  Another one is using cold temps (ice, compressed air, etc) to get the metals to shrink/ expand.

 

Tim

 

 

********************
Tim Potter
Coordinator
MSU Bikes Service Center
B10 Bessey Hall/ Michigan St. University
Along the N. River Trail, 300 ft. west of Farm Ln. Bridge
E. Lansing, MI 48824-1033

Ph: 517/432-3400
Fax: 517/432-2743
Email:
bikes@msu.edu
Web: www.bikes.msu.edu
Home Dept:
www.transportation.pp.msu.edu


From: thethinktank-bounces@bikecollectives.org [mailto:thethinktank-bounces@bikecollectives.org] On Behalf Of Colin Dixon, Phoenix Bikes
Sent: Wednesday, August 06, 2008 12:18 PM
To: The Think Tank
Subject: Re: [TheThinkTank] stuck seat post tip

 

Vice advice is right on - posting an ad for a good ole vice for a community bike shop could get one donated. Lots of folks with unused shops out there.

 

The other thing to try on a seatpost is to take the bottom bracket out, put the frame in a stand and flip it upside down, then drip some penetrating oil in the seat tube. This takes some time, but worth trying before in there with a hacksaw or risking damaging a sweet frame by pounding & wrenching.

 

- Colin
 


 

On 8/6/08, Mark Rehder <mark@re-cycles.ca> wrote:

On 6-Aug-08, at 10:37 AM, Bob Giordano wrote:

a vise is good for stuck seat posts.  flip over the bike, insert seat post
into vise, tighten -but not too much to crush post-, move bike frame back
and forth gently and smoothly while pulling up.  be very careful to use
smooth motions and 2 or 3 people as to not tweak frame.



Yeah, we have a 4" vise and it has come in very handy for things like this.  It of course also needs to be bolted to a strong, sturdy table.

any other 'stuck seat post' tips?

-Bob Giordano,
Free Cycles Missoula



Sheldon has the answer(s):

http://www.sheldonbrown.com/stuck-seatposts.html

Cheers,

Mark Rehder
http://re-cycles.ca


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