Seized carbon post in Merida frame.. Extraction advice needed

jonnya777

Hello All,
I have a Merida ride 300 tiagra. The carbon seatpost is exrtremely tight in the seat tube...I have tried pouring 2 kettles of hot water at the top of the seat tube to expand the tube and release the seatpost...It didnt work.

Trying to most the post the vice (even with a wood bung in the centre of seatpost (seat clamp element removed)) destroyed the carbon fiber...all i could see I could do was saw the post and push it into the frame and just insert a new post.

Problem!! It went an inch and a half into the frame (below the line of seatpost clamp and doesnt seem to want to go any further. The top of the seat tube is 32mm and widens towards the bottom to 35mm. Is there anything down the seat tube that would prevent it from moving? watter bottle eyelets? I dont want to damage frame by hitting too hard...but pushing it in further seems the easiest option. Out of sight and mind :-)

Also...is there any way of getting it out. The post does obviously move but is extremely tight. Ideally I would still like to get it out..

Any thoughts please.

Cheers Jon.

ugo.santalucia

you'll probably have to saw it or drill it out if you find the right bit

ugo.santalucia

If the seatpost is 27.2 mm, then something like this might work

https://www.zoro.co.uk/shop/cutting-tools/carbide-tipped/26mm-carbide-tipped-hole-saw/p/ZT1147841X?utm_source=google&utm_campaign=pla+|+Cutting Tools&utm_term=ZT1147841X&utm_medium=pla_css_1&mkwid=VL8eHh4I-dc&pcrid=377670179978&pkw=&pmt=&prodid=ZT1147841X&slid=&pgrid={groupid}&ptaid=aud-907798550281:pla-392378352387&gclid=Cj0KCQjw0YD4BRD2ARIsAHwmKVniFWAIXHeC4pGLo6DVOszMdULU133PZEaiXUJuJ8zX3d7iH6i1AD0aAjk1EALw_wcB

or you can try a 27 mm one, if you are brave

jonnya777

Thanks you very much for that..I will definately consider doing that. I also have access to someone who could weld a rod to insert and catch the bottom of post and weld a contact point at top of rod to hit with a hammer? Your thoughts on that?

ugo.santalucia

Sounds dangerous... those aluminium frames are paper thin... I wouldn't use a hammer. You are lucky the post is carbon and a drill bit will shred it easily... had it been metal, you would be in bigger trouble

lesfirth

The nut inserts for your water bottle can be removed ( drilled out) allowing the seat post to go further down . You would probably have to drill through the old seat post which would be blocking the bottle carrier holes to fit new bottle nut inserts. You do not have to insert all your new seat post into the seat tube . Saw off the excess length,just have the minimum that is required.
If you attempt to use an improvised rod for extraction consider the use of a " slide hammer puller" in the design rather than having to hit something with a hammer.
Good luck .Let us know how you go on.

arlowood

Another option could be using an expanding reamer to get rid of the residual carbon seatpost. You can get sizes that will expand from 23.75 to 27mm which would take out all or the majority of the carbon. Anything left would be wafer thin and should be easy to remove hopefully.

An example of what I am suggesting is here :

https://www.kfrozin.com/index.php?main_page=product_info&products_id=129407

Cheap enough at £14

ugo.santalucia

arlowood said:

Another option could be using an expanding reamer to get rid of the residual carbon seatpost. You can get sizes that will expand from 23.75 to 27mm which would take out all or the majority of the carbon. Anything left would be wafer thin and should be easy to remove hopefully.

An example of what I am suggesting is here :

https://www.kfrozin.com/index.php?main_page=product_info&products_id=129407

Cheap enough at £14

Nice... didn't even know it existed

jonnya777

Thank you for all of this information. I will look into them Thanks again Jon.

davidof

Next time try doing it like this

https://youtu.be/Bfb6Ejb7pS4