Pesky Stuck Seat Post

[RyanW]

Hello all,

I have madly (after doing two a few years ago) decided to bring back to life two old road bikes.

I always start first by making sure everything moves, and sure enough the seat post on one of them is stuck fast. I have read the SB post which i am following however it all surrounds, or seem to, posts which are some what out of the down tube, this one however is fully in. So I cannot work out if its rusted in, or just gone too far down.

Suggestions on a post card please

On a side note, is there any interest in vintage bike restoration threads?

Ryan

 

[RyanW]

 

[cyberknight]

plus gas squirted into the seat tube and allow to soak a while then if you can stick the seaptpost in a vice and heave ho the frame seems to be the way to go if i remember rightly.

 

[Mattonsea]

Best of luck , I was given an old Peugeot frame I tried everything , duck oil, light heat, nothing got it out.

 

[mjr]

Restoration threads seem popular in the vintage section... good luck with that... you may find local motor spares unlock sprays sufficient if you struggle to get plus gas: it was for my stuck stem!

 

[KneesUp]

If it's an aluminium post you won't have much luck with lubrication.

The easiest way is to cut off the top, seal the frame and dissolve it. Look it up on youtube. Note that chemicals are dangerous and it only works with an aluminium post in a steel frame.

 

[PeteXXX]

If you don't want to keep the seapost, clamp some molegrips on it and keep wiggling it. Eventually it should free up. Squirt a lubricant on the area as you do it.

 

[midlife]

Best of luck, just out of curiosity what's the frame? Looks a bit Orbit ish.

Shaun

 

[Drago]

Caustic soda.

 

[RyanW]

Thanks for all the advice do far. Sprayed 1/2 a bottle of gt85 on it, will try the vice/ turn bike trick tomorrow then look at the more drastic options.

It's Raleigh road ace ex fyi.

 

[sittingbull]

If the BB is out, up-end the frame and squirt PlusGas into the seat tube to attack the post from both ends, or try and squirt some through the bottle cage mount holes.

Alternatively the acid in Coke is supposed to work by dissolving the aluminium oxide which has built up.

 

[cardiac case]

Hi Ryan.
Because when the clamp bolt was originally tightened the post was inserted too far it will have shrunk the frame
to a smaller diameter or/and pulled it out of round. The material will not have sprung open when the bolt was undone.

If the gap that was pulled together is wide enough you can hold a nut in the gap, then screw a bolt/set screw in the threaded side
till it goes through the nut and into the unthreaded side of the frame. Holding the head of the bolt/set screw with one spanner
undo the nut along the thread.This will open up the gap and enlarge the i.d. of the frame.

If the gap is too small for a nut then a metal wedge, maybe a large screwdriver blade, can be tapped into the gap to open
it up.

Which ever method is used to open up the frame the seat post will just lift out since the Plus Gas, WD40 has already been applied.

HTH
Paul G
(Engineerly)

 

[RyanW]

Hello,

Thanks for the help so far. I spent 3 hours or so this evening (plus a few hours over the past few days) trying to free this up, but have come to the conclusion its well stuck. So I will go down the caustic route. Wish me luck....

PS. Why are these seat posts so thick! My modern bike is maybe 2mm alu, this thing is probs near on 10!

 

[2clepto]

got mine out with all the lubricants suggested above, which didnt work at all until i purchased a 36" pipe wrench. id had the seat post soaking in nlubricant for 2 weeks until the pipe wrench arrived. ive got a vice now too that may be easier seen as you have a square end on the top of your post. you'll be really happy and satisfied once it shifts a few millimeters, spray it again and then come back an hour later.

 

[ChrisEyles]

Unfortunately, if it's an alu post in a steel frame, they can corrode in pretty permanently - I've recently had this problem on a stuck stem and did a lot of googling around for solutions. No amount of heat, penetrating oil, or good old fashioned brute force could persuade my stem to budge an inch (I gave up and am leaving it at the - rather high - position I found it in)!

I wasn't brave enough to try the caustic option myself (and the bike isn't worth the effort TBH) - good luck with this, hope it works! Be careful not to leave the basic solution in the tube for too long, or it may damage the steel tubing (at least from what I gather on t'interweb). I'm guessing you have already tried @cardiac case and others advice.

Would love to see a resto diary if you get the stuck post out

ps - agree about the thickness of the old seat posts - especially since there used to be much less showing compared to a modern bike!