Seatpost removal

Daz555

Just one last check before I go home tonight and go for the "hacksaw and peel" approach.

My brother in law has donated his old Saracen Kili Comp to me as a base for my new commuter but irritatingly it has an alu seatpost stuck in its CroMo (as far as I can tell) frame. I'm looking for any inspiration as to removing it. Tried so far (along with normal penetrating oil etc):

Twisting with saddle attached - ripped off the seat clamp from the post.
Cooling the seatpost with ice, clamping and attempting to twist.
Drilling a hole in the post, inserting bar and attempting to twist - resulted in the seatpost tearing at the drill point.
Flattening and clamping the seatpost with grips and twisting - resulted in tearing a section off the seatpost.

Any more bright ideas? My brother in law is a lanky sod so I still have tons of seatpost to work with.

kinmofo

i never had this problem, so its a bit of a guess, but if there is room, hit it with a hammer, as if you're trying to make it go inside furthur, it might brake the seal that's formed.

just making sure, but have you loosened the seat post clamp?

ride_whenever

Either saw it off about an inch above the frame, and using a hacksaw blade tensioned with a spoke, cut down the inside then use the shaft of a flat head screwdriver as a chisel, cut down between the frame and seatpost. It should then just come out.

Alternatively, use a strong solution of caustic soda and replace when the frame cools after each application. It'll burn the post right out. However do this outside and be really careful with the chemicals.

fastmongrel

Take it too a proper bike shop who can ream out the post with the proper tools.

If you get nowhere with the above its a steel frame and you dont mind the paint being knackered use a gas torch and heat the ally post till it melts and runs out. The post will melt before you cause any permanent damage but obviously your paintjob is fucked.

cooldad

Dynamite.

Daz555

I've tried hammering it as well.

I was too busy last night to look at this again so I'll have another go this weekend. I first going to try gripping the seatpost in a vice and then twisting the frame (mate has a big vice and workbench) and if that fails it will have the be the ball-ache of cutting a slit into the post - I have one of them single ended hacksaw jobbies which should do the trick.

Don't really fancy messing around with chemicals so I'll get it to my LBS to sort as a last resort.

1mancity2

Daz555 wrote:

I've tried hammering it as well.

I was too busy last night to look at this again so I'll have another go this weekend. I first going to try gripping the seatpost in a vice and then twisting the frame (mate has a big vice and workbench) and if that fails it will have the be the ball-ache of cutting a slit into the post - I have one of them single ended hacksaw jobbies which should do the trick.

Don't really fancy messing around with chemicals so I'll get it to my LBS to sort as a last resort.

Put something inside the post if you can to stop it squashing flat, I use this method and its never failed yet.

Put penetrating oil on the seatpost leave a while, whack it in the vice, frame in the air and use the frame as leverage.

Start with small twisting actions and eventually it will make a "crack" noise then start applying more pressure and a twisting upward movement.

saladdays

Try removing the bottom bracket, place bike upside-down and pour caustic soda in through the bottom bracket shell.

Daz555

Update.

Popped round to my mates house today who has a nice big work bench and massive vice. I hammered a section of broom handle into the post to stop it crushing and then gripped it in the vice.

After much careful twisting we eventually heard and encouraging crack and the post started to move. Came out very easily after that.

Now that is sorted I can finish turning it into my new commuter. New middle ring, some new brake blocks and some road tyres is all it needs.

Daz555

Update 2:

Well nowt is simple is it? I have a new 27.2 seatpost (measured and confirmed correct size) and it won't slide in more than about 8cm. Grrr.

I have scrubbed the inside with a wire brush and had the LBS have a go as well. Still no joy.

Off to Argos Cycles in Bristol next to get it drilled out. I'm assuming there is a lot of oxidised metal in there from the stuck seatpost.