Seat post problem

Talk about anything.

Moderators: Bearbonesnorm, Taylor, Chew

Post Reply
ozboz
Posts: 89
Joined: Thu Apr 25, 2019 10:15 am
Location: Richmond u Thames

Seat post problem

Post by ozboz »

Hiya, I need to nudge my saddle up a bit but it won’t move with usual man handling, it’s a carbon frame with carbon seat post , I don’t want to use penetrating oil I’ve heard it’s not compatible wit carbon, it’s a pear shaped post so twisting is a no go,also reluctant to start bashing it , any suggestions most welcome !
User avatar
Bearbonesnorm
Posts: 23904
Joined: Sun Jun 05, 2011 8:53 pm
Location: my own little world

Re: Seat post problem

Post by Bearbonesnorm »

My first thought is a slide hammer. Using it might involve damaging the saddle if you're unlucky but it won't damage the frame and shouldn't damage the post.

Cheap enough to buy: https://www.ebay.co.uk/p/Silverline-380 ... 742&chn=ps
May the bridges you burn light your way
User avatar
Pirahna
Posts: 829
Joined: Tue Nov 05, 2013 8:42 pm
Location: Alicante

Re: Seat post problem

Post by Pirahna »

Piece of wood under the saddle and give that a tap with a hammer, get someone to hold the bike for you.
Lazarus
Posts: 3598
Joined: Fri Aug 30, 2013 10:49 am

Re: Seat post problem

Post by Lazarus »

http://theseatpostman.com/

never used but this guy specialises in removing stuck posts
ScotRoutes
Posts: 8144
Joined: Mon Mar 18, 2013 9:56 am

Re: Seat post problem

Post by ScotRoutes »

Try hitting the seatpost further in. Sometimes it's just a question of breaking any stiction and this is easier than trying to hammer it out.
redefined_cycles
Posts: 9282
Joined: Tue Sep 20, 2016 8:19 am
Location: Dewsbury, West Yorkshire

Re: Seat post problem

Post by redefined_cycles »

This can be a bit of a nasty problem as thr carbon (AFAIK) welds (or melds or whatever the appropriate word is for resin sticking to resin cos there was nothing holding the two componenets of carbon fibre apart) to each other.... I'm guessing that you (might have used carbon paste but) haven't moved the post up or down in a very long while...

Ive successfully managed to remove alu and steel stuff (obviousoy with heat) but the delicacy of carbon means "I'd measure thrice" then.... take 8t to a specialist... Unless off course your frames not too special (which I imagine it is). Also... dont expect you seat post to make it out of this trauma alive, good sir

:-bd sorry for you dilemma

Shafiq
redefined_cycles
Posts: 9282
Joined: Tue Sep 20, 2016 8:19 am
Location: Dewsbury, West Yorkshire

Re: Seat post problem

Post by redefined_cycles »

Nb... obviously Stu knows alot more bout carbon and much anything else to do with bikes/engineering than many if us (myself included)... I dont know how to use a slide hammer but if its gonna push the seatpost in whilst being able to knock the hammer( and thus the post) upwards... then it could well work (depending on how long the seizure has been stuck (quite literally) in there...
User avatar
Pirahna
Posts: 829
Joined: Tue Nov 05, 2013 8:42 pm
Location: Alicante

Re: Seat post problem

Post by Pirahna »

Plan B - longer crank arms. :smile:
User avatar
Bearbonesnorm
Posts: 23904
Joined: Sun Jun 05, 2011 8:53 pm
Location: my own little world

Re: Seat post problem

Post by Bearbonesnorm »

Shafiq, the bottom of the shaft on a slide hammer attaches to the object that requires moving. You then use the heavy sliding weight against the stop at the top of the shaft ... think of it as a hammer that pulls rather than pushes.
May the bridges you burn light your way
User avatar
Escape Goat
Posts: 2600
Joined: Thu Nov 01, 2018 10:41 pm
Location: Not nearly close enough to Scotland...

Re: Seat post problem

Post by Escape Goat »

Lazarus wrote: Tue Apr 30, 2019 11:53 am http://theseatpostman.com/

never used but this guy specialises in removing stuck posts

We send all our sticky post customers there. He's very good (say the people that report back!)
redefined_cycles
Posts: 9282
Joined: Tue Sep 20, 2016 8:19 am
Location: Dewsbury, West Yorkshire

Re: Seat post problem

Post by redefined_cycles »

Yes. Thanks Stu (as always, always learning). I took a look on youtube and seen it. Engenious tools out there aint they and thanks for bringing to my attention. Its something Ive previously made (the concept but in a simpler guise and not quite slidy) and had I had the slide hammer it wouldn't have erm needed making :grin: ...

Azboz. If you do manage to get hold of a slidy hammer or use that concept, dont forget that if your seatpost isn't one long carbon shaft piece, then you might run into the problem that the head of the post - where the rails attachement is - if its a seperate welded/glued on alu head, will end up knocking out well before the post starts budging from the seattube (happeend to me previously on a carbon laminate 2 piece post, just before I got put the burner gun thingy (on steel off course).

To remedy above problem, you might be good strenghening the joint between the 2 pieces but remember, gorilla tape in of it self, will not work (in this situation)...

Another thing (which I reckon you would end up doing eventually but hopefully you'll report back sooner that it came out alot easier) is that eventually you might needs to cut the head of the seatpost off (to get inside it) and then carefully cut some vertical slots downwards on the inside. This would weaken the structure of the seatpost inside the bikes tube. Dont forget though, dont cut the seatpost so short that you are then stuck afterwards trying to make something strong enoigh to hold to attach slidy hammer or whatever.

Not sure if that helps (hopefully it does and it doenst spund all gibberish)...

*take a peek at items 13 and 14 on here https://www.sheldonbrown.com/stuck-seatposts.html

13 is what I was talkijg about (but with not as good explanation as my English is pretty bad :-bd ) point 14 is by a clever engineer (but I dont think it would work in your case as yours is most likely welded/epoxied together as opposed to the friction in his situation as iy was only left for a couple weeks)...

If you do go for point 14 then dont forget: upside down frame (to tug up on the frame) and seatpost in a vice (could be) is your friend :grin: oh the joys of trying to figure out nasty problems/solutions
ozboz
Posts: 89
Joined: Thu Apr 25, 2019 10:15 am
Location: Richmond u Thames

Re: Seat post problem

Post by ozboz »

Thanks for all replie fellas, but I did solve it last night,
I lashed the saddle to a ceiling hook with about a 50 mm gap between rear tyre an floor , then I sat on the crossbar and gently bumped up and down : It did ease its way out , no damage .......success!!
Once again thanks for input 😉
User avatar
Bearbonesnorm
Posts: 23904
Joined: Sun Jun 05, 2011 8:53 pm
Location: my own little world

Re: Seat post problem

Post by Bearbonesnorm »

You are like a great big slide hammer ... good job :-bd
May the bridges you burn light your way
User avatar
benp1
Posts: 4051
Joined: Sat Dec 07, 2013 7:36 pm
Location: South Downs

Re: Seat post problem

Post by benp1 »

Good job.

I read that post and was expecting you to say the ceiling caved in :grin:
redefined_cycles
Posts: 9282
Joined: Tue Sep 20, 2016 8:19 am
Location: Dewsbury, West Yorkshire

Re: Seat post problem

Post by redefined_cycles »

Bearbonesnorm wrote: Wed May 01, 2019 8:54 am You are like a great big slide hammer ... good job :-bd
This.. +1...

What you (Ozboz) did there is what that engineer person in the Ahwldon Brown article also commended/recommended/did... He had some reason for not pulling on the seatpost (as it has some sort of fractional elasticity apparently and it causes the post the expand inside the tube) but rather pulling on the frame/seattube around it.

Well done
ozboz
Posts: 89
Joined: Thu Apr 25, 2019 10:15 am
Location: Richmond u Thames

Re: Seat post problem

Post by ozboz »

Ceiling cave in !
ozboz
Posts: 89
Joined: Thu Apr 25, 2019 10:15 am
Location: Richmond u Thames

Re: Seat post problem

Post by ozboz »

Such cheek !
I’m a very nimble and fit 14 stones the cake and beer muscle could do with a work though !😀
User avatar
Dave Barter
Posts: 3594
Joined: Sun Jun 16, 2013 6:21 pm

Re: Seat post problem

Post by Dave Barter »

Escape Goat wrote: Tue Apr 30, 2019 9:50 pm
Lazarus wrote: Tue Apr 30, 2019 11:53 am http://theseatpostman.com/

never used but this guy specialises in removing stuck posts

We send all our sticky post customers there. He's very good (say the people that report back!)
I used him, highly recommended
Elite keyboard warrior, DNF'er, Swearer
Post Reply