Author Topic: Supergoose Seatpost Problem - A BIG ONE (Read 12152 times)

750Rush · « **on:** March 17, 2012, 02:27 PM »

Well, I thought it felt slightly heavy when I bought it, but now I know why.

After filling the seatpost with coca-cola and letting it sit for the morning, I attahed the stem to it, them the forks to the stem and with some more WD40 had a good old twist (it was very stiff) this is what I found:

Nothing like a big iron rod to make a super light race bike $:-\$

So much for what I thought would be a nice blue rental seat post too.

The seat post was twisting off the iron bar. I've tried to twist the iron bar out with some molegrips on it, but it won't shift. My question is, how the heck is it stuck in? I know there is a small crack on the frame where the seatpost inserts, but wouldn't it have been easier to weld that back up?

Any help or advice would be much appreciated as I have already paid far too much for this bike as it had a cracked rear tuff and now this

Bob_Acid · « **Reply #1 on:** March 17, 2012, 02:35 PM »

I would hazard a guess that you have a seat post stuck in there and someone has hammered the bar down into it to hold the post on the top

750Rush · « **Reply #2 on:** March 17, 2012, 02:40 PM »

How do I get it all out?

sawzall · « **Reply #3 on:** March 17, 2012, 02:51 PM »

you could try welding a bar on top of post forming a "T" then put it in a vice and try turning it

rooski · « **Reply #4 on:** March 17, 2012, 02:57 PM »

You need to get a big slide hammer,

Drill and tap the end of the bar,screw a bolt in there,and attach it to the slide hammer

get someone to hold the frame and get hammering

looks like this

steve69 · « **Reply #5 on:** March 17, 2012, 03:02 PM »

flip it over and stick the rod in a bench vise, do it up FT and give the frame a twist, and/or caustic the rest out $:-\$

BENDYCAT ELEVENTEEN · « **Reply #6 on:** March 17, 2012, 03:30 PM »

I might suggest some thing else before you try that lot - right see if this makes sense

The original owner has a renthal seat post but wants to take it out - snaps it off down in the seat tube - some clever bloke says you never get it out, but if we get another seat post the same, we can then cut it down and stick a rod of metal between the two to join them together ~ with enough new seat post down the seat tube it will stay they as the metal rod is holding both in - lock it down with a seat clamp and hey presto your ready to go !

i would suggest trying the caustic soda route

i had a renthal post stuck and they do seem to weld/bond them selfs in well - take a little while to do but might be the best way and not twist the frame in any way

if the bottom bit of seat tube is renthal, then it might melt out and the iron rod will brake/drop out and you will then have a clear empty seat tube to use

it's just a thought before you twist the frame or try to drill out ?

what do you lot think ?

cheers B

rick1970 · « **Reply #7 on:** March 17, 2012, 05:48 PM »

JESUS

ive seen a few stuck post threads but that is the worst by far

good luck mate hope you get it sorted

BENDYCAT ELEVENTEEN · « **Reply #8 on:** March 17, 2012, 06:06 PM »

they do come out - in the end

h2ggv · « **Reply #9 on:** March 17, 2012, 06:06 PM »

It's ok getting the metal bar out but then how do you get the rest of the old seat post out $:-\$

BENDYCAT ELEVENTEEN · « **Reply #10 on:** March 17, 2012, 06:27 PM »

the causic sode eats the alloy metal and dissolves it - it just turns to a mush that you have to wash out ever so oftern and put some more stuff in with hot water - in the end it's all gone

takes time, but is a good way if you are not sure that you don't want to damage it or know how to drill it out !

h2ggv · « **Reply #11 on:** March 17, 2012, 06:36 PM »

Quote from: BENDYCAT ELEVENTEEN on March 17, 2012, 06:27 PM

the causic sode eats the alloy metal and dissolves it - it just turns to a mush that you have to wash out ever so oftern and put some more stuff in with hot water - in the end it's all gone

takes time, but is a good way if you are not sure that you don't want to damage it or know how to drill it out !

That's the only way then or a machine shop to drill it out

750Rush · « **Reply #12 on:** March 17, 2012, 08:17 PM »

I've just got back in. Many thansk for the advice. Where can you but caustic soda from, B&Q?

Will it damage the chrome if it spills?

I suppose the tube will need re-chroming anyway once I can find someone to weld it?

Sorry for all the questions!

dan-dare · « **Reply #13 on:** March 17, 2012, 08:24 PM »

Caustic will only damage non-ferrous metals...

BENDYCAT ELEVENTEEN · « **Reply #14 on:** March 17, 2012, 08:28 PM »

should be ok on chrome - but as you say re-chrome or a paint will be on the cards

you can get it on ebay - maybe ask other members which they like best

does take a bit of time - but works

Discostu · « **Reply #15 on:** March 17, 2012, 08:36 PM »

Yeah good advise bendy. Caustic soda mixed up strong. Remember to be gloved up etc and away from kids as it is nasty stuff. You will need to do it in a well ventilated area as well. Be patient and the alloy post will break up leaving you with the steel rod which be loose.

750Rush · « **Reply #16 on:** March 17, 2012, 09:23 PM »

Many thanks everyone. Some project this is turning out to be

BENDYCAT ELEVENTEEN · « **Reply #17 on:** March 17, 2012, 10:36 PM »

wouldn't be as fun if it was too easy

Clean · « **Reply #18 on:** March 17, 2012, 10:38 PM »

Quote from: discostu on March 17, 2012, 08:36 PM

Yeah good advise bendy. Caustic soda mixed up strong. Remember to be gloved up etc and away from kids as it is nasty stuff. You will need to do it in a well ventilated area as well. Be patient and the alloy post will break up leaving you with the steel rod which be loose.

Caustic ain't gonna eat up a solid iron / mild steel bar anytime in the next 20 years, surely?

Alien blood is what you need!

BENDYCAT ELEVENTEEN · « **Reply #19 on:** March 17, 2012, 10:48 PM »

~~glen~~ sorry Rich

if the iron rod is in the rethal alloy post at the bootom of the seat post tube, it will come out easy

750Rush · « **Reply #20 on:** March 20, 2012, 03:14 PM »

Will this stuff from Homebase work?

http://www.homebase.co.uk/webapp/wcs/stores/servlet/ProductDisplay?langId=110&storeId=10151&partNumber=799726

animal · « **Reply #21 on:** March 20, 2012, 04:55 PM »

Yes thats the stuff

Definately go for dissolving the ally seatpost from around the bar and seatpost tube

Use wam water 4 the caustic and do it where u can keep it walm if u can

I use a blow torch 2 reheat mine when its gone cold . This will b slowly slowly catchy money time tho

Don't expect it 2 work in minutes. wash out the mixture after a day and refill etc .

Pooch · « **Reply #22 on:** March 20, 2012, 08:15 PM »

Took about 3days or so for mine to dissolve .. Worked really well

Bob_Acid · « **Reply #23 on:** March 21, 2012, 09:15 AM »

is the post that's stuck in there definitely alloy and not steel?

BENDYCAT ELEVENTEEN · « **Reply #24 on:** March 21, 2012, 09:45 AM »

Find in a couple of years when it's not shifting that much

Author Topic: Supergoose Seatpost Problem - A BIG ONE (Read 12152 times)

750Rush

750Rush

h2ggv

h2ggv

750Rush

dan-dare

750Rush

Clean

750Rush