The dreaded stuck seatpost thread #574

al-onestare

al-onestare

BoTM Winner
Kona Fan
Yeah yeah, I know it's been done to death (suggestion for the mods - a forum for FAQ for restoring would be dead handy and save on the repeated questions) but some advice would be ace and much appreciated.

Kona CC 1988, so steel frame, original seat-post which I assume is alloy. Stuck like a MF. Top tips please.

I've read about the saw technique, the twist and shout, the bathe it in lube for 3 months, acetone whilst trying not to destroy your paintwork...what's been your most successful method other than the lbs route?
 
If you have a bench vice - clamp the post and twist the frame upside down. After spraying some light as poss lube down it.
 
Following on from last post:

I agree with the upside down bike in vice method.

But if you mash the head of the seatpost in the vice (which I've done before), saw it off as close to the frame as you can, then put a spoke down there to see how far it goes down.

My method of choice is a hacksaw blade and between 1-3 hrs work!

I know some people blowtorch the frame to expand it, put I'm not a fan of wrecking the paintwork.
 
It all depends how stuck the seat post is.

1) the bench vice method works for stuckish seat posts that is not really stuck. Repeated application of Plusgas cannot hurt at all.
2) I have tried the hacksaw method and gave up as it was simply a pain and that was with a blade driven by an air compressor. If the post is long then there is a lot to cut, hense I gave up.
3) Aceetylene torch heating the alloy post till it melted worked very well. It also gives you the exuse to get the frame powdercoated in your favourite colour. This is how I delt with my Kona stuck seatpost. I would not worry about the integrity of the steel frame ine has been fine afterwords. You only have to heat up to about 700 celcius i.e very dull red glow before ally starts to melt.

Powdercoating a frame sets me back £30 + delivery to the powder coaters and pick up.

I personally would not risk and alkaine solution method (is it caustic soda or ammonia solution?) either way there is a significant risk to you here. I am used to handling hazzardous chemicals and this method makes me nervous.
 
Just one thing to consider - if you have a heat treated frame then the Acetylene / melting technique will eliminate the heat treatment.
 
^ true if you get it hot enough. for steel the anneal temperature is ~900 celcius hold it at that and heat treatment will go but it takes a while and ally will melt below that temperature so I am not sure if it really is a problem for this method.
 
the padsaw method has the post out in about 2 hours, tops. As long as you're careful, no harm comes to the frame or the paint.

Saying that, over 5 years and about 15-20 different bikes, only once have i ever had to resort to it. Most come free with a bit of welly and some lube.
 
I would plug the seatpost best you can then try whichever method you want. But a week of soaking in penetrating oil is really worthwhile (not WD40).

I have used this and mole grips, and also the vice technique. The penetrating oil does half the work for you.
 
I'll mention this again, because it's worked for me on more than one occasion: If your frame is steel and the post is aluminum/post is steel and frame is aluminum, Ammonia will dissolve the galvanic corrosion that can occur between the two metals. Ammonia won't bother your paint or clearcoat, either, but it does need time to work, similar to penetrating oil. Worth a try anyway as it's cheap and a common household item.

Also, WD-40 is not a true penetrating oil, it's made to lubricate and displace water (WD stands for Water Displacement). True penetrating oils have the ability to creep into very tight spaces if given the time. Over here in the US we have several brands, Kroil, Liquid Wrench, PB Blaster, etc.
 
loads of penetraing oil and a 3 foot pair of stilsons.

Get a friend to hold teh frame whilst you swing on the stillies.

Sorted a few stuck seatposts with this method. The seat post is scrap at the end btw.
 
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