The seatpost in my commuter is stuck: steel frame, alloy post. Surprised it’s happened as I make conscious effort to remove and reapply carbon paste every 6 months or so.

Am I best to tackle it now, i.e. if I leave it in place is it likely to become even harder to shift in future? It’s not an issue at the moment as the posts’s at the correct height for me, but I’m concerned about ignoring the problem for future. Also concerned about damaging frame and/or post if I try to get it out now.

What would STW do?

i’d try to get it out now, give everything a good clean and then put back in with some grease instead of carbon paste

Deffo sort it sooner rather than later. Its only going to get worse!
Out of interest why did you use carbon paste and not waterproof grease? Slippage issues?

Buy some penetrating oil.

If it’s only been stuck 6 months (surely shorter) then it will come out easy enough.

Get it out now.

Whatever you do don’t saw the chuffing thing down to get it out. I’ve seen this so many times on older bikes and it makes it mucg harder to remove the post.

After using some penetrating oil (not WD40 It’s hopeless) use the saddle as leverage – clamp it in a vice (use another sacrifical saddle if needed) and twist the frame. If the post has a head on it which can be clamped that might work as well. Bear in mind that even pressure when turning the frame to release the post might not work – it needs a sudden jolt to break the corrosion apart. A dead blow hammer hitting a block of wood on the head tube can work well. You might have to give it some real welly too – don’t be afraid! The CRACK when it releases is both scary and satisfying at the same time.

Use copper slip next time on the post if it isn’t going to be moving much. Plenty of it! And maybe seal the area around the clamp too with an inner tube to stop water getting it but make sure water isn’t being trapped in there.

The longer it’s left the more stuck it’s going to become, so doing it sooner rather than later would be my preference.

The seatpost in the vice and twisting the frame might work. Exercise caution as you can exert a lot of force on the seat tube that the frame was never intended to experience. IE, don’t go mental.

I’ve removed two stuck seatposts. Both resulted in the demise of the post. One using a home made slide hammer and the other by cutting of the saddle rails and splitting the alloy post inside the frame. Once split the expansive force is released and the remains are easily extracted.

D.

I had the same thing years ago, Tange Prestige frame & an Easton seatpost. Even the use of diesel didn’t work so I did what Davesport did.
Honestly though, try diesel before you go mad with the hacksaw blade.

theseatpostman.com

sooner rather than later. if it’s hard, you can console yourself that getting it unstuck is as easy as it’s ever going to be (this time round)

What you can try for starters is slacken off the bolt, penetrating oil round the post and slot, and go for a ride, sitting down more than you usually do. A bit of jiggling might do the job for you. Try twisting it with your thighs, too.

If you need more, this is what I did: I don’t know if the coke actually did anything, it’s supposed to dissolve ally oxidation.

– coca cola down the seattube over a weekend
– forcing apart the clamp slot and spraying GT85 (I used the handle of a table knife in an adjutable spanner)
– boiling water round the top of the seattube.
– twist the saddle as hard as you can , bracing the frame with a foot and/or a wall.
– Once you’ve got it moving a bit, then comes the mighty heaving:
– left foot in the downtube/seattube junction, heel of the right hand pushing the back of the saddle towards me, left hand on the nose, pulling and twisting. I won about a millimeter of seatpost per quarter turn, then I had to return it to center for another twist n pull.
– apply more boiling water when it starts to get trickier, every 3 or 4 quarter turns
– repeat as necessary.
wear gloves! I lost skin on 2 fingers and have a big blister in the palm of my hand.

I would suggest never opening up the seat clamp slot as it ovalises the area and looks a mess. There’s no need to do it.

GT85 wont work either.

If you have a lot of post stuck in there, use penetrating oil from either the bottom bracket and spray with bike upside down, or same but from seattube water bottle holes.

Shelden brown has a good simple guide if you google it.

Pretty conclusive answer then – thanks folks. I’ll start with penetrating oil and not go mental, I’ve no desire for a replacement frame just yet. Genuinely surprised it’s managed to get stuck. Full-length guards so no road spray from the top. Sees a lot of rain so I’ll look into a suitably sized inner tube to butcher for a seal.

Bigyinn – yup, carbon paste over grease due to previous slippage issues (which I’d happy trade for current issue), resolved by swapping to the current Thomson post which has that sort of ribbed finish.

chipsngravy – thanks, heard of him before but cost possibly outstrips value of frame.

A friend had a result from the seatpostman, he seems to have the knack.

Once you get the post out, If you’re still worried about slipping, use Hylomar Blue instead of grease. It’s a non setting gasketing compound, It’s cheap and will do the same job as carbon paste whilst also preventing the parts corroding together.

It’s not an issue at the moment as the posts’s at the correct height for me, but I’m concerned about ignoring the problem for future.

When will it become a problem then?

I had similar on my last commuter, although the saddle was a touch low (~5mm or so). I had a bit of a go getting it out, but as the friendly local bike shop said when I had a chat about options, “why bother, it’ll only end up under a car sooner or later”. It didn’t, it cracked.

Just ride it.

I would suggest never opening up the seat clamp slot as it ovalises the area and looks a mess. There’s no need to do it.

Me neither, just meant a little light flexing to help the oil around. Should have been clearer, obviously. Ta.

Sorry ned, not a criticism, but seeing the butchery on retrobike of some attempts worth repeating.

If you have slipage issues after suggest a salsa fliplock. Stopped my thomson/parkwood issues.

It was totally fair criticism! 😀 “Forcing” doesn’t convey the same message as “a little light flexing”. Especially as the frame I did that^ on was aluminium. and not mine.

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