seized seat post solutions?

les_dennis

I bought a nice fuji team issue bike yesterday. Only problem is the seat post has seized and I can't shift it! I don't want to put too much pressure on it in case I damage the frame. It's a carbon fibre frame and an alloy seat post. I'm patiently soaking it in GT85 but any top tips to get is shifted would be welcome as I can't wait to get out on the bike. If that doesn't work then I'm gonna resort to the patient hacksaw method.

Cheers

Les

robbarker

Try icing the seatpost. It might contract sufficiently to loosen it.

martinwitnam

Where did you buy this bike from?
Surely a seat post wouldn't have seized up in one day?
Take it back to where you bought it from.

les_dennis

Martin

Sorry I should have explained more. I bought the bike second hand and I already knew that it had a seized seatpost so was able to knock some money off the price. I want to try and avoid having to cut the seatpost but will do this as a last resort. Therefore, any tips on un-seizing it that avoid me having to cut the post will be warmly welcomed!

Rob: thanks for the tip - I'll definitely give it a go

Les D

Shadowduck

How are you trying to free it at the moment? A twisting action is more likely to free it off (and avoid damaging anything) than a straight pull. If there's a fair bit of seatpost sticking out you could even try gently tapping it inwards a bit - once you've got it moving (in any direction) it should come out without too much trouble.

Anonymous

Have you tried asking a hundred people?

les_dennis

Shadowduck - I'm repeatedly spraying it with gt85 and have tried twisting the post and knockint it downwards with a rubber mallet. No movement so far. This is day 2 of the GT85 treatment. I reckon I'll give it till Saturday before I get the hacksaw out

les_dennis

Anton - I used to get the Les Dennis stuff all the time at school. Well, that was till the bullying got too bad and I ended up in a white jacket where the arms tied behind the back :twisted:

Shadowduck

That doesn't sound good. Maybe a little more twisting force would do it but obviously you don't want to risk damaging the frame... How much leverage are you putting on at the moment?

How exactly is the hacksaw going to help? Surely you'd just leave a piece stuck in the frame? Or is the idea to use a hacksaw blade to slot the sides of the stem where it's stuck in the frame?

(Edit to Add: I didn't understand Anton's comment at all until you responded to it. D'Oh!)

andyp

les_dennis wrote:

Shadowduck - I'm repeatedly spraying it with gt85 and have tried twisting the post and knockint it downwards with a rubber mallet. No movement so far. This is day 2 of the GT85 treatment. I reckon I'll give it till Saturday before I get the hacksaw out

Stop wasting GT85 and get down to your local hardware store and ask for a can of Plus Gas. That is a proper penetrating oil that should do a better job than GT85, which is a general purpose lubricant.

Then, should that fail, read this.

The hacksaw method really should be your last resort.

ymh

what I did with mine, took it to work, had the fitter apply heat to the seat post wth the welding kit, (remove saddle first, and protect frame well ) then used the large monkey wrench to twist seat post (used the seat clamp on seat post to get the grip) post loosened easy, then went in the bin

martinwitnam

Surely if you apply heat to the seat post it will expand and will become an even tighter fit in the frame and even harder to remove?

les_dennis

Thanks for the tips and especially for Andy P's link. I've just checked out the seat post and it's carbon fibre also and pretty expensive. I'm not sure whether it makes any difference that both post and frame are carbon fibre but it does mean I'm more reluctant to get out the hacksaw. I'm gonna try the plus gas with a healthy dose of patience...

Monty Dog

To complicate things, although the frame's carbon, there's a likelihood that there's an aluminium liner to the seat collar - which probably explains why the post has become seized due to corrosion with the carbon - may be worth checking on bike spec to make sure. Carbon typically doesn't stick to itself. Try holding the seatpost head in a vice and turning the frame for leverage.

aracer

Monty Dog wrote:

To complicate things, although the frame's carbon, there's a likelihood that there's an aluminium liner to the seat collar - which probably explains why the post has become seized due to corrosion with the carbon - may be worth checking on bike spec to make sure. Carbon typically doesn't stick to itself. Try holding the seatpost head in a vice and turning the frame for leverage.

No alu liner in the seat tube on any of the carbon frames I've owned (5 and counting). However I have had carbon seatposts stick in them - not entirely sure of the mechanism.

robbarker

Unfortunately if both frame and post are carbon, my earlier suggestion of cooling the seatpost won't work, and you may have done more harm than good witht he GT - it may cause the resin in the carbon composite to expand, making the problem worse. It's likely the thing is sticking int he first place because it waslubricated, which is supposed to be a bad move according to most manufacturer's blurb I've read. At this point I think I'd be reacing for the dremel and the surgeon's steady hands...

Uranus

aracer wrote:

No alu liner in the seat tube on any of the carbon frames I've owned (5 and counting). However I have had carbon seatposts stick in them - not entirely sure of the mechanism.

I wonder if the top lacquer coat and / or the resin in the composite materials tend to suffer like the gel coats on GRP boats if left immersed in water, leading to absoption of the water at a micro-porous level and consequent swelling of the material?

I know it's probably an epoxy resin rather than a polyester one, but I don't know if epoxies are totally immune to this effect?

Until or unless seatposts have an effective seal on them, it seems to me that they all need to be removed and dried after every ride in wet conditions, water inevitably gets in there.

les_dennis

B*gger! I guess I should have gathered all the information before cracking on, which is a recurring problem for me! :oops:

I had a word with my local bike shop (York Cycleworks). The guy I spoke to reckoned the seizure was probably caused by the previous owner mistakenly lubing the post. He also reckoned I could use the method involving inverting the bike and pouring coke through the bottom bracket into the seat tube and leave it for a couple of days. They've got some experience of doing this and I think I've reached the point where I'm gonna have a proffesional look at it. I just want to get out and cycle before the weather gets too bad!

Thanks for the advice chaps - please let me know of anymore ideas that might get me on the road quicker

les_dennis

Finally got it sorted at the weekend through about 3 hours of careful sawing with a pad saw. Managed to saw and break off a quarter of the post and then squeeze the rest of the post together with some pliers and twist it out, The bottom of the post had totally corroded and changed to a grey powder!

Thanks for your help

stjohnswell

I just managed to remove a seized carbon fibre post from a aluminum frame.

Got the guys at work to twist it left-right. No joy.

Turned bike upside down, squirted loads of WD40 in through seat tube bottle eyelet, left overnight. No joy.

Gently used a hair-dryer to heat the seat-tube around around the area of the seatstays until warm. Result!

N0bodyOfTheGoat

The inverted bike and coke method saved my bacon on a Peugeot 531 bike I had in the mid 90s... The seat post easily moved after letting the coke do its thing for a couple of days (before which the post was completely jammed)!

geoff_ss

NitrousOxide wrote:

The inverted bike and coke method saved my bacon on a Peugeot 531 bike I had in the mid 90s... The seat post easily moved after letting the coke do its thing for a couple of days (before which the post was completely jammed)!

Blimey if it does that to a seat post think what it does to your insides I'm glad I hardly ever touch it. A worthwhile tip though.

I had stuck seat post in my 653 frame last year. After days of soaking it still wouldn't shift so more drastic measures were needed. It had broken already at the seat clamp so I sawed it off square, rested the bottom bracket on a block of wood after removing the wheels and thumped it hard with a big hammer downwards. That worked fine; once it had moved I was able to grasp it with a pair of stilsons and twist it out.

Strangely, the technique was suggested by my friends on a model aircraft forum. Most of them find it quite strange that I ride bike. I suppose the reverse applies here

Geoff

yannigr

I have learnt the hard way that all seat post are not the same by fitting one alloy on which was too large in a steel frame.

After trying WD 40 and brute force I have managed to sort it out the following way:

Filled a carrier bag with ice, wrapped the bag around the seat post, warmed the frame with a hairdryer... and the post came without any major effort. It was disappointedly easy considering I had spent several hours before without any luck.

I had tried the ice on its own before without success.

Doobz

cool thread on how to get one out that has stuck but what would be best preventive method to stop this ever happening?

feel

Doobz wrote:

cool thread on how to get one out that has stuck but what would be best preventive method to stop this ever happening?

methods of freeing depend very much on the two materials that are seized as do the methods for prevention.Combinations of ali and steel can be greased, but i think anything involving carbon should be kept dry and regularly removed.