Seatpost stuck in Frame

Chewy Cheeks

My own bike has got its rear mech really bent out of shape, tried to realign it myself - wished I didnt now, anyway I'm off to the skillful but grubby menders on Saturday morning for a dressing down and a solution to my cross threading skills.

Consequently I am on my sons Claude Buter Montain bike - to cut a long story short the seat post is stuck in the frame and it needs to be raised about 6-8 inches. I have loosened the bolts, prised the post housing but still it ain't shifting. (and I whacked it a few times, pointless but satisfying)

Has anyone any sensible suggestions for someone who doesn't have an extensive workshop

DavidTQ

anything usefull here:-

http://sheldonbrown.com/stuck-seatposts.html

attica

WD40?

attica

and if you get it out, grease the darned thing before you put it back in to stop this happening again!

Belv

My LBS had to file the remains of my seat post out of my commuter when i wanted to change from a suspension to a normal post. It had been in there for four years without moving (or greasing!).

Chewy Cheeks

Thanks for the tips - its aluminium so ammonia seem helpful.

WD 40 is ready to hand so I will start with a soaking tonight.

discurio

get an old saddle on there and whack that in a vice then use the frame a a filthy big lever and try to twist it loose after coating with wd40 . this has worked for me before without any damage.

elcani

I recently had the same problem. Now it's fixed!

The seatpost was alloy and the frame was steel, so ammonia seemed the best idea. Getting hold of some was the first problem, neither Wilkinsons or my LHS (local hardware shop ) had any, so I had to get it here http://tinyurl.com/yvsbtn

I didn't want to take the bottom bracket out (to allow me to get the ammonia in), but the seatpost was fluted with the flutes extending down into the frame, so I used a syringe to inject ammonia into the flutes, hoping it would soak down and break the bond. About twice a day, I'd go into the cellar to 'treat the patient' with more ammonia, feeling like a bit of a madman.

After a few days of this, I took it to a mate's who has a bench vice, took off the saddle, clamped the post in the vice and twisted and lifted the frame. It came out relatively easily. The thing is, I don't really know how much (if at all) the ammonia helped, so I would definitely try the vice first. Messing around with ammonia is tedious. If you don't know anybody with a vice, take it to a bike shop and see if they will have a quick go. Maybe you could buy something to sweeten them up a bit.

If all else fails, I don't think the hacksaw option would be too bad. You can get a close quarter hacksaw here http://tinyurl.com/68p2vx which should allow access into the tube to cut the slits.

Good luck!

tubby531

You could heat the seat post with a hairdryer then let it cool down.The expansion and contraction could break the seal.

Belv

tubby531 wrote:

You could heat the seat post with a hairdryer then let it cool down.The expansion and contraction could break the seal.

Speaking from experience, this doesn't work if the frame is steel and the seatpost is alu. I later found out (from Sheldon's site, i think) this is because alu expands quicker than steel so if will, if anything, make it a tighter fit.
Wish i'd tried that ammonia thing.

graham_g

I got some ammonia from the local hardware store only to find that the bottom bracket was stuck too (annoyed at this as it means the LBS of a few years back didn't use cany grease/copperslip) so I couldn't pour the ammonia in. That one's off to the tip!

hamboman

Belv wrote:

tubby531 wrote:

You could heat the seat post with a hairdryer then let it cool down.The expansion and contraction could break the seal.

Speaking from experience, this doesn't work if the frame is steel and the seatpost is alu. I later found out (from Sheldon's site, i think) this is because alu expands quicker than steel so if will, if anything, make it a tighter fit.
Wish i'd tried that ammonia thing.

That's why you heat only the frame and stop before it starts to heat the post itself.

Chewy Cheeks

More fun and games last night - the WD40 soak was left for a couple of days.

Tried to release it keeping the seat in place , huffed and puffed and pulled the seat and its aluminiium plinth(I'm sure there is a better term for this), up and out leaving the seatpost intact and firmly in place. Sulked, drank beer - heating to break the seal seems a long way off.

I can see the cycling motion being somewhat less than elegant for a while.

Thanks for all the tips - thats all