F***** Seat Post

[J4CKO]

I have an old Diamondback Topanga Rigid MTB on road tyres, dug it out cleaned it up so I can leave it at the leisure centre rather than a grands worth of Cannondale and accesories for some scumbag to nick or ruin.

Anyway, decides to adjust the seat......


Anyway, there then follows a long and drawn out series of attempts to twist, smack, twat, freeze heat, WD40, cut, twist, swear, skin knuckles etc in an attempt to move the seat, now there is very little stem left above the tube, its been mole gripped down to nothing, two channels vut down it with a hacksaw, it still wont move.

So, I need to drill it out, has anyone got ay experience of this, I think its a 27.2 mm stem, where would youget a drill that big ?

Dont want to bin it as otherwise its quite nice and quite sentimental really.

 

[Ivan Ardon]

Alloy? It's time to dissolve it with caustic soda solution.

 

[eldudino]

How about drilling a hole right through the post and putting through a lever of some sorts so you can get some real torque on it without worrying about molegrips slipping.

Put lots of penetrating fluid on the joint for a week before you do it.

 

[gbb]

I have an old Diamondback Topanga Rigid MTB on road tyres, dug it out cleaned it up so I can leave it at the leisure centre rather than a grands worth of Cannondale and accesories for some scumbag to nick or ruin.

Anyway, decides to adjust the seat......


Anyway, there then follows a long and drawn out series of attempts to twist, smack, twat, freeze heat, WD40, cut, twist, swear, skin knuckles etc in an attempt to move the seat, now there is very little stem left above the tube, its been mole gripped down to nothing, two channels vut down it with a hacksaw, it still wont move.

So, I need to drill it out, has anyone got ay experience of this, I think its a 27.2 mm stem, where would youget a drill that big ?


Dont want to bin it as otherwise its quite nice and quite sentimental really.

Forget that one for several reasons..
I doubt anyone does a 27.2 mm drill.
If they do, it will cost a fortune (£20, £30 maybe for a decent drill bit)
You'd struggle to control it if you did get it in a chuck.
It probaby wouldnt fit in a normal 1/2 chuck anyway


One of the girls at work has the same problem with a Scott MTB. I've been soaking it with WD ..upturned the frame and sprayed it into the downtube via the bottle bosses, had a mother of an adjustable spanner on the squarish top section of the seat mount...it aint budging yet
Its not my bike so ive got to tread carefull, but right now i'm running out of ideas that dont involve brute force and potential damage.

 

[HJ]

Try Sheldon Brown's advice...

 

[Black Sheep]

Forget that one for several reasons..
I doubt anyone does a 27.2 mm drill.
If they do, it will cost a fortune (£20, £30 maybe for a decent drill bit)
You'd struggle to control it if you did get it in a chuck.
It probaby wouldnt fit in a normal 1/2 chuck anyway

30 mm drill does indeed cost about £30, it has a narrower section to allow it to fit in a normal chuck, however, unless you've got a drill that has a chuck that uses a key - forget it, the torque it produces when it sticks just spins it in the chuck.

 

[Black Sheep]

WD40 and GT85 are the lightweights of unsticking things

you need plusgas or gunk's 'liquid wrench'

paraffin also works well, but stinks badly (use it to un-stick seized engines)

 

[mickle]

Diamondback Topanga is 26.8mm being chromoly.

 

[fossyant]

Think it's going to be a plus gas and tip upside down and soak it for a few days sort of job.....

 

[02GF74]

some posts will even defeat Sheldon Brown. hacksaw sound fine in theory but the post can be quite long inside the frame so you will not get to all of it.

I had this happen - the post snapped off - bit I drilled hole in it and use a punch to lever it out of the frame. lemme get a photo of it.....

 

[02GF74]

here is photo.

you have to try to cut a slot in the post so as to weaken its grip on the frame.

 

[dellzeqq]

The Sheldon screwdriver in the gap and twist tip is good, but bear in mind that an alloy frame will be dented by a steel screwdriver, so see if you can find a screwdriver with a blade that is almost as thick as the gap between the two portions of the seat tube.

Plusgas, repeated once a day for several days.

Drilling out is iffy - you heat the post, it expands. I've never had the need to do this, but it's always struck me that immersing the free end of the seatpost in dry ice might work.

 

[nickb]

Not much use here I know but to help prevent this happening I slide a 3" length of inner tube over the seat post/seat tube to stop all the crap getting into the tube. Works well over the headset too.

 

[J4CKO]

Ok, will get some PlusGas, my dad works in one of the last engineering type places in the UK (or thats what it feels like) so they might be able to do something, its fairly well worthless but even though I could go and get another I cant bear waste, as a kid I always felt a bike a was a precious and valuable thing, your transport, your freedom and I seem to have carried that into adulthood so it pees me off when I cant do something or when the kids treat their bikes like crap, plus I like them to see how things get fixed.

Think It might get sent into my dads work but will try the Pulsgas first, tried Plumbers freezer spray to no avail.

 

[Ivan Ardon]

You're wasting your time with oily things, you'll need something that removes aluminium oxide. Ammonia solution, for instance.