Seat post stuck

veetwin

Hi all, I have a Giant Defy 1 with an aluminium frame and carbon seat post. I have bike about 5 years and never had a need to move the saddle until yesterday when my son wanted to try it out.

I used an allen key to remove the retaining bracket assuming it would easily move up and down but to no avail. Numerous squirts of WD40 had no effect either. Any thoughts? Don't want to go too hard at it for fear of damaging the carbon post.

Cee-Jay-Cee

Get a phosphoric based descaler.

Turn your bike upside down and trickle the descaler into the seat tube. You’ll need to fill the seat tube to above the level the seat tube is at.

Depending on the seat tube design you may need to seal the top of the seatpost to prevent the descaler leaking out.

Hambini recently removed one from a frame he bought using the same method. His frame was carbon but it shouldn’t make any difference and it’ll also work on alloy/carbon.

https://youtu.be/Vq2DMbQurkg

Don't Chute!

I had the same problem with the same bike last year. Was sending it over to Sweden so gave it to Cycle Plus in Greystones to pack up. They tried everything to remove the seat post and nothing worked. They just had to pack the bike with the seat post in place. I think they had it for over a week and no joy!

Grassey

I've had luck squirting wd40 in over the course of a day and letting it see down. Then stand over the top tube and twist

byrnem31

I have a 2020 defy and needed to move the seat post down. I undone the screw and it still wouldn't budge.

I found out they have a wedge system in them when the mechanic was showing me. You need an Allen key fitting with a handle on it and bang the back of the handle when it's in the bolt and this looses the whole system.

Weepsie

Plusgas is better than wd40.

Eamonnator

Cee-Jay-Cee wrote: »

Get a phosphoric based descaler.

Turn your bike upside down and trickle the descaler into the seat tube. You’ll need to fill the seat tube to above the level the seat tube is at.

Depending on the seat tube design you may need to seal the top of the seatpost to prevent the descaler leaking out.

Hambini recently removed one from a frame he bought using the same method. His frame was carbon but it shouldn’t make any difference and it’ll also work on alloy/carbon.

https://youtu.be/Vq2DMbQurkg

Has anybody first hand experience of this method?

veetwin

Thanks all, I'll drop by the LBS (Giant dealer) first and if that doesn't work I might give the descaler a go.

Don't Chute!

I think the problem with mine is that the seatpost is ‘D’ shaped so couldn’t be twisted to break any seizures.

veetwin

So LBS said the Seat Post and the aluminium frame have chemically bonded and the only solution is to cut off the post and cut the remaining part of the post from the inside of the frame with a hacksaw blade. He did not recommend the descaler

John Hutton

veetwin wrote: »

So LBS said the Seat Post and the aluminium frame have chemically bonded and the only solution is to cut off the post and cut the remaining part of the post from the inside of the frame with a hacksaw blade. He did not recommend the descaler

Well I guess the son ain't getting to use the bike! If it's a grand height for you I'd just leave it

veetwin

John Hutton wrote: »

Well I guess the son ain't getting to use the bike! If it's a grand height for you I'd just leave it

That's true except that I had planned to sell the bike as I've just got a new one on the BTW Scheme

magicbastarder

why not try the descaler?

veetwin

He said that would remove all the grease from the recently serviced Bottom Bracket

hesker

I have read several accounts of people doing the hacksaw job. Some of them on frames of significant enough value so I wouldn’t be afraid of it. Patience is needed as well as new blades. Old blades make any cutting job a pain.

Google hacksaw seatpost removal and I’m sure you’ll find several accounts with pics included

magicbastarder

veetwin wrote: »

He said that would remove all the grease from the recently serviced Bottom Bracket

probably cheaper to have it regreased than replacing a carbon seatpost though?

cajonlardo

Pro team mechanics used to remove bb and then turn fram upside down and pour coca cola through seatube. Havent heard anyone doing it in years but a quick google shows results.

Many years since Ive worked in a bike shop but I did cut them out a couple of times when all else failed

Eamonnator

cajonlardo wrote: »

Pro team mechanics used to remove bb and then turn fram upside down and pour coca cola through seatube. Havent heard anyone doing it in years but a quick google shows results.

Many years since Ive worked in a bike shop but I did cut them out a couple of times when all else failed

Coca Cola has a certain amount of phosphoric acid in it, so same principle as Hambini's method.

veetwin

magicbastarder wrote: »

probably cheaper to have it regreased than replacing a carbon seatpost though?

As it's going up for sale it will be getting the cheapest seat post known to man. The most expensive one won't add a cent in value to a six year old bike.

CramCycle

veetwin wrote: »

He said that would remove all the grease from the recently serviced Bottom Bracket

Upside down and put it through the bolt holders for the bottle holders?

bazermc

Have ye tried yelling at it yet?

veetwin

bazermc wrote: »

Have ye tried yelling at it yet?

That and even a lump hammer all to no avail. Mini Grinder being prepped at present

veetwin

CramCycle wrote: »

Upside down and put it through the bolt holders for the bottle holders?

Currently giving this s go. Will report further

magicbastarder

if your partner walks in on you while you're doing this, just tell them the bike is thirsty.

Eamonnator

veetwin wrote: »

Currently giving this s go. Will report further

with some photos, please, if possible.

cajonlardo

Winner!

https://www.bikeradar.com/news/stuck-seatpost-removal/

veetwin

Ok, 5 days later and the saga continues. I gave it two good soaks of descaler two days running. Clamped the saddle in a vice and eventually managed to turn it slightly but still unable to remove it. Saddle at this stage is wrecked.

Next up attacked with the mini grinder then a hacksaw blade and more penetrating oil and eventually a hammer and screwdriver. Parts still remain. Myself and a neighbour were still at it at 10pm last night and eventually gave up the ghost. Will conduct the final assault after work this evening. If this leads to failure the mini grinder will be deployed again and the bike will end up in bits in the bin

cletus

We need pictures of this

tonytiger81

I’ve been that cowboy. Tried everything before trying to “gently” cut it out with a reciprocating saw. Cracked the top of the seat tube with the vibrations, then lost the rag completely and went to town on it

tonytiger81

I've been that cowboy. Tried everything before trying to "gently" cut it out with a reciprocating saw. Cracked the top of the seat tube with the vibrations, then lost the rag completely and went to town on it

CramCycle

cajonlardo wrote: »

Winner!

https://www.bikeradar.com/news/stuck-seatpost-removal/

This one is immensely satisfying: https://www.instagram.com/p/CCYYC0Tnsb6/