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RADBMX.CO.UK  |  Technical & Reference Section  |  Tech and Restoration  |  old chestnut - stuck seatpost - help!
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Author Topic: old chestnut - stuck seatpost - help!  (Read 989 times)

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Offline generallee

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old chestnut - stuck seatpost - help!
« on: October 27, 2007, 01:39 PM »
i have a cromo obinson frame with a stuck alloy seatpost ... ive tried wd40 - nothing doing -
also tried heating the frame to expand the metal a bit- still wont budge - I dont have a vice or workshop with huge clamping machines so cant try that - any solutions that anyones ever come up with would be much much much appreciated!
steve

firebird

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Re: old chestnut - stuck seatpost - help!
« Reply #1 on: October 27, 2007, 03:43 PM »
try a pipe freeze kit from the plumbers, then heat it up. it has worked for me in the past.

bmx xxx

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Re: old chestnut - stuck seatpost - help!
« Reply #2 on: October 27, 2007, 04:06 PM »
drill a hole right through the seat post, then put a screwdriver through it and try to turn it, will soaking it in wd 40 or take out the crank set and turn the frame upside down and try to spray the wd 40 down the tube, hope you shift it fella,

Offline lazychubs

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Re: old chestnut - stuck seatpost - help!
« Reply #3 on: October 27, 2007, 05:11 PM »
or fill the seat tube with cuastic soda
as it will eat the post and not damage the chromo frame
make surs there's no holes in the bottom bracket or it will
run out lol

djgivvinup

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Re: old chestnut - stuck seatpost - help!
« Reply #4 on: October 27, 2007, 05:24 PM »
Big pipe wrench should do it maybe?!  :-\

Offline sawzall

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Re: old chestnut - stuck seatpost - help!
« Reply #5 on: October 27, 2007, 05:35 PM »
steve its a last resort but i had to drill one out recently :D took nearly 2 hours but saved the frame :daumenhoch:

British race frames and race clothing wanted

Offline generallee

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Re: old chestnut - stuck seatpost - help!
« Reply #6 on: October 27, 2007, 09:28 PM »
my god im going to try ALL of these suggections - where can I get caustic soda from? Cheers lads. steve

Offline CD17

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Re: old chestnut - stuck seatpost - help!
« Reply #7 on: October 27, 2007, 09:31 PM »
The Caustic Soda sounds like your best bet, the trouble with heating it up, the post will expand a lot more than the frame because its alloy.

Offline TwoBobRob

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Re: old chestnut - stuck seatpost - help!
« Reply #8 on: October 28, 2007, 09:34 AM »
Diesel is a good oil to use.  Nice and light and will penetrate most joints eventually. Try and find a way to soak that area overnight or summat.

Also, it's worth smacking it down into the frame as well, just to get it moving. Once it's gone that way, its sure to go the other   ;)

Offline Swivel

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Re: old chestnut - stuck seatpost - help!
« Reply #9 on: October 28, 2007, 10:26 AM »
Hi mate, we tried everything for nearly 2 weeks with my Pro Performer, then my brother thought sod it and replaced the tube (as he works in a sheet metal firm) but ours was stuck right to the bottom of the tube and completely rusted in, hence giving it all some sort of weld. Nothing worked apart from basically replacing the tube. As far as I know, Diesel is a good option and heating it up, put it in a vice and give it a good belting  :knuppel2:

Best of luck, Matt  :daumenhoch:

greentoad

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Re: old chestnut - stuck seatpost - help!
« Reply #10 on: October 31, 2007, 09:09 PM »
Hi

I have got numerous stuck posts out using the normal methods, but I once tried for about 8 months to get an alloy post out and with no result (I really wanted to save the seat post, and the frame was too fragile to risk damage).

The only way that I finally had success was by cutting off the seat post about 20mm above the frame and drilling the centre out (it was a solid DX). I started on a slow speed setting with a pilot drill then moved up the drill bit sizes.

With a large enough hole, I then then used a hack saw blade (not an electric saw) and sawed through very carefully up and down. After a few blisters, and just before the post was actually sawn right through, you can squeeze the top of the post with vice grips and it will reduce in size just enough. Then it is just a case of moving 1mm left, 1mm right (I never go heavy handed), use some sewing machine oil (3 in 1 is good too) down the sides and with more moving left and right out they come.

This has worked a few times for me, and I have even managed to save the seat posts.

J.


Offline generallee

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Re: old chestnut - stuck seatpost - help!
« Reply #11 on: November 02, 2007, 02:20 PM »
some v interesting methods there, thanks for all the info - I tried the caustic soda - nothing doing tho which was a bummer. In the end I had an idea - the frame that has the stuck post is a 90's Robinson frame, nothing special but still pretty nice, 1.1/8" headtube and canti mounts, and the dreaded seatpost which is a 25.4MM DIAMETER -
so I cut the seatpost off where it enters the frame, then hascksawed dwon the seatpost slightly where the split in the seattube is where the seatclamp pinches, and hey [resto - an instant shim that now allows me to run a 22.2mm diameter setapost in there perfectly! It works really well, and after I have it powdercoated itll look fine!
Thought youd all like an update!
cheers.

RADBMX.CO.UK  |  Technical & Reference Section  |  Tech and Restoration  |  old chestnut - stuck seatpost - help!
 

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