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Last night I got fed up with the creaking going on with my bike. I took apart and put together the headset and bottom bracket. As I went to tackle the seat post I realised it was well and truly stuck! I have ridden it a few miles without the clamp on and soaked in WD40 but no movement.
The frame is a Van Nicholas Yukon and the seat post is a 27.2mm Deda RS EL Alloy one.
I looked at Sheldon Brown's tips but no joy. I have neither a vice nor dry ice to hand (my tool box is very sparse).
A mate that does triathlons suggested boiling hot water but I'm not sure.
Any sage advice on freeing things up would be great.
The bike is currently upside down in my shed with a bottle cage screw udone and litres of WD40 sprayed into the seat tube.
Caustic soda - won't affect Ti but will dissolve Al. It'll ruin the post and also any Al shim bonded into the Ti frame, so check the frame spec first ..
If you don't want to take any chances, this bloke comes well recommended.
http://www.theseatpostman.com/
Destroy the post or go without the bike for a while. Both seems quite drastic!
The thing is the post is at the right height for me. It seems it was the bottom bracket creaking so with that fixed the bike is silent again. I just don't like the idea of the post being seized though....
Wish I'd thought the same. Stuck seat post at exactly the right height so it has been left, until Sunday when I had a big off and snapped it. Now even more difficult to remove
Ouch!
With the post now not salvageable surely you can use a more drastic measure. Advice on the net seems to quickly escalate to using a hacksaw on the offending post!
I'm still in denial, imagining I can save both frame and post....
I'm still in denial, imagining I can save both frame and post....
You can. Go to the seatpost man.
Undo the clamp and ride it. it will move eventually.
Or jam the seat post head in a door frame. Maybe a gate is better. Twist the frame. Much more leverage that way. A vice is better but if you don't have one.....
Twist the frame. Much more leverage that way.
You may also snap the frame as it's not designed to be loaded like that.
I got a stuck alloy dropper post out of a steel frame by using a wooden mallet, freeze spray and boiling water to release it and then twisting it out with the frame in a workmate and two G-clamps around the post.
the frame is not designed for the sort of torsional load applied by twisting
I am sure if you apply enough force something will give but it may not be the bonding in the post
Nope. In theory yes but post will give first.
Nope. In theory yes but post will give first.
Can you guarantee that a chemically bonded joint of as much as 100 sq.cm area is going in be weaker than a weld of far less than 1 sq.cm area?
Nope, but I've never broken a frame with a seized seat post by clamping the post in a vice and twisting. And I've done quite a few!
The bond between seatpost and frame has always gone first.
Hit it with a big mallet - into the frame. You're trying to break the bond and this is often easier than trying to pull it out. Once mobile, you'll have more chance of extracting it.
Seatpost in a door/gate/vice and twisting the frame off is normally quite successful.
Try Rost Off Ice. I've removed a ticht post with this before.
Try using the CO2 canisters used to inflate tyres or a CO2 fire extinguisher instead of the dry ice?
Hacksaw works. I've done this a couple of times, and you need a sharp blade and a sharp chisel, but it works. It's quite satisfying when it finally releases
Any holes near bottom bracket to pour come down the seat tube and leave for a day before tipping right way up and using mallet on saddle?
Worked a treat on a stick post on my old Peugeot ~20 years ago.
Take saddle off of seatpost; find an odd bit of scrap metal that sits nicely on top of the seatpost; use a hammer drill on "hammer only" setting to apply lots and lots and lots of impacts to the top of the seatpost . . . if you're lucky the seatpost will gradually start to move; once you're broken the bond you stand a decent chance of being able to pull it free.
Any holes near bottom bracket to pour come down the seat tube
This does not sound good
😆
Any holes near bottom bracket to pour come down the seat tube
This does not sound good
Any holes near bottom bracket to pour come down the seat tube
This does not sound good
If it saves post and frame, I'm sure OP will be up for anything.
Mmm, how should i use a co2 cannister. I actually have some of these and like the idea of bike shed science experiments.
I dont even know what a hammer drill is :-/
The bike spent all night up side down having had wd40 sprayed through the bottle cage hole. Not the slightest movement.
Dont have a rubber mallet. Perhaps a proper hammer and a bit of wood might suffice?
Continue to ride the bike without the seat post collar but no joy yet. However i quite like the minimalist look 🙂
Refit saddle.
Replace seat post clamp.
Go ride.
It's not going to get any more stuck. The seat post will have oxidized and aluminium oxide is bigger than aluminium.
Wait until you don't want the seat post any more or can be without the frame for a while.
When that time comes, either the seat post guy, costic soda then cut and ream, in that order I'd say. Seat post guy might even be able to save the post.
My personal favourite method involves a tin of copaslip and a time machine.
You may also snap the frame as it's not designed to be loaded like that.
Bullshit, this is the tried and tested method of removal used in every bikeshop across the land and more than likely 'mr seatpost removal'
Post in vice...
1: A good hard yank, hit it with a hammer
2: A dose of GT85.
3: Blowtorch.
4. Drill the post out
I'd leave it.
You will destroy the post to get it out so just leave it till you need it out.
Plusgas and big vice worked for me.
Twist frame, seat post in big vice.
Had exactly the same problem on a Merlin frame. Quick trip down the diy shop for a waterpipe freezing kit. Fit it to the seatpost and freeze the post. Using the saddle as leverage I managed to wiggle it out.
Oops, gg tablet predictive text! 😆
I meant coke inside downtube of upside down bike!
I've seen someone open a seattube like a sardine can by trying to twist out a seatpost. WD40 is useless, use something like ACF50 or Plusgas.
Sudocrem.
As per dovebiker, WD40 is useless for this. Plusgas - and for a good week of regular topping up - may work, or caustic soda but accept you'll wave goodbye to your post.
pour come
How much? Do you measure in ml or ejaculations?
I always swore by plus gas but coke worked for me last time. tip frame upside own squirt a can of coke in with a squeeze bottle via the bottle cage holes in the seat tube
clamp seat post in a vice & keep twisting. the resultant cracking noise when it finally gives is music to the ears. thought I had snapped the seat post at first though. It may however take a few days for the coke to penetrate and may go a bit flat!
God I should really stop drinking coke
(Edit: Hehe definitely checked the auto complete on that one)
At least you won't get a seatpost stuck anywhere...
I thought that the titanium used in bike frames was an alloy of titanium and a small amount of aluminium (3%?).
So using caustic soda on it - would that do bad things to the Al in the metal?
@oldnpastit - a quick Google hasn't given me a definitive answer. Pure [url= http://www.azom.com/article.aspx?ArticleID=1336 ]titanium [/url]is very corrosion resistant but alloys less so.
If it was mine I'd be using freeze spray to get differential contraction first - build a dam around the seat post and keep spraying into that, then hot air gun on the frame.
Or send it off to someone who knows what they're doing.