Seatpost corroded in Carbon frame - HELP

[Noblies]

Hi Guys

 

My seatpost has been corroded in the carbon frame. How do i get it loose?

 

Help needed please.

 

Thanx Guys

[Patchelicious]

A few threads on here, do a search.

 

But many of them say that turn your bike upside down and pour some coke down the seat tube and leave overnight. Should loosen in the morning.

 

Edit: that’s Coke a Cola, just to be clear.

[Pulse]

Assuming its an Aluminium seatpost, you can follow Patch's Coke approach.

[eddy]

When all else fails, a hacksaw blade and a very steady hand got mine out

[Malpiet]

Hot water and some Q20 sprayed in the grooves and left over night, its most of the time only a small piece of the insert thats corroded.

[Onlybikes]

This might sound crazy but if it's an aluminium post you can try Q20 and pull it out but I have found that trying to cool the post down with a few Co2 bombs often helps it come loose , or if you are desperate , take a car battery and short it on the post and get the sparks flying . That should do the trick

[Fox3]

A few threads on here, do a search.

But many of them say that turn your bike upside down and pour some coke down the seat tube and leave overnight. Should loosen in the morning.

Edit: that’s Coke a Cola, just to be clear.

Had a good laugh on your coke a cola edit

[WIPEOUT 1000]

I spent the best part of 2 weeks slowly cutting out a stuck Thompson seat post out of a frame. I really struggled with the hacksaw blades and then tried a round file in combination with a hand drilll which worked really well.

 

My major learnings were:

1. Do not ever let it happen again

2. Take your time, it's very easy to destroy your seat tube.

[Shebeen]

Hi Guys

 

My seatpost has been corroded in the carbon frame. How do i get it loose?

 

Help needed please.

 

Thanx Guys

ALU or carbon seat post?

[BaGearA]

Coke a cola

Q20

contract the seatpost with cold

 

 

In that order

 

 

The last one should work , pour boiling water over the seat tube then try to get ice cold water down the seatpost 

 

 

Seat tube should expand like A millionth of A mm and seatpost contract the same amount and that's usually enough ( have done this with many threaded BB's )

[Patchelicious]

Coke a cola

Q20

contract the seatpost with cold

 

 

In that order

 

 

The last one should work , pour boiling water over the seat tube then try to get ice cold water down the seatpost

 

 

Seat tube should expand like A millionth of A mm and seatpost contract the same amount and that's usually enough ( have done this with many threaded BB's )

What are you doing to your BBs that they keep getting stuck?

[TheJ]

I got the same problem. Question. Throw coke down the seattube... it will mos go down into the bb. Turn the bike upside down and it runs out the seatpost again. Huh?

[Calculus Bikes]

Short note on the "engineering" side of the corroded seat post:

 

(Warning: do not continue to read if you are not a really boring person)

 

The chemical process is known as Galvanic Corrosion,  it takes place when there is contact between an "anode" and "cathode" material.  We had to do quite a lot of research on this topic to prevent it in our Bamboo bikes where the lugs are made from CF and the dropouts from Alum. 

 

Prevention is better than cure, so if you have a CF frame, use a CF post.  If you have to use an Alum post, use one that is anodized so there is a "barrier" between the CF and Alum.  If you have to use an uncoated Alum post, bookmark this forum to refer back to someday.

 

Further reading if you're burning for more info:

https://www.corrosionpedia.com/galvanic-corrosion-of-metals-connected-to-carbon-fiber-reinforced-polymers/2/1556

 

Good luck with the blades and coke!

[Prince Albert Cycles]

Try all the Coke etc and put the bike upside down with the saddle in a vice and use the leverage by pushing pulling on the wheel.

[BaGearA]

What are you doing to your BBs that they keep getting stuck?

I'd never let that happen to my BB    

 

Friends or shop I work at  

[michaelbiker]

Not very helpful, but I had this problem with an alu seatpost in a carbon frame. Eventually had to take to the LBS who eventually got it out (by magic I assume)

 

This is a problem you only ever get once. After that carbon assembly compound will be your next buy.

 

Good luck!