morten_beta

Hi All!

I have recently found an old roadbike, which I am converting to fixed. However, when I took the bike apart the seatpost was really stuck... I got it out and some corrosion was on the post. I got a new one same size but longer, and it will only go in so far - so far being about the length of the old seatpost.

Could the old one have been hammered in? I cannot feel any difference on the down tube (no "bulkyness"), and when I put light in there and look down onto it, the only thing I see is some corrosion and a straight tube... Is it normal for the seatpost to stop somewhere down the tube? And last but not least should I just shorten my new seatpost, and use it?

Thanks in advance
Morten

mparker326

A hacksaw is your friend.

AngryScientist 

its likely hitting some obstruction like the water bottle bosses... take a closer look at whats going on, and try not to force anything.

rarebird

you could chop it but you need your post to go at least to a safe depth, if its only getting 1 or 2 inches in you shouldnt chop to accommodate that. then u may need to have a new plan. the mechanics forum could tell you if getting rid of the corrosion is a do

BLACK BIKE

If you are pretty sure that the old post was hammered in, there can't be much harm in hammering in the new one. Be sure to use a sledge hammer with a weight of no less than 32 ounces, and don't stop hammering until it's all the way in there.

morten_beta

Hey All!

Thanks for your answers. Just to make sure everything is clear.

The old seatpost is out.
I am able to get a new one in about 9 inches, before it stops.
Nothing like lugs or bosses stops the new one, it just "wedges in".

I was mostly nervous if there was any risks in using the frame, if the old seatpost had been forced in?
As I wrote, when I shine a light down there it looks smooth (aside from the corrosion of course).

Does anyone know if there will always be a "sharp bulk" when a post has been hammered in? Because I don't see or feel any. I was just really wondering why the new one suddently stops...

Thanks again
Morten

ianjk

9 inches? wow. just cut the thing!

queerpunk

wait.

did you use grease?

mparker326

New seatposts are so much longer than they used to be. The manufacturer didn't plan for a foot of seatpost to be in there so I'm sure the tolerance is off further down you go.

I had the same trouble on one of my bikes and just shortened the post.

IbikezLA

if you see a bunch of corrosion in there then that may have just been what kept the seat post in there.

operator

What a bunch of ******** advice.

1) Put down the hammer
2) Ream out the seat tube and clean. Drill + soft brush reamer = key
3) Make triple sure that is the seatpost size the frame is supposed to take, it's not unusual for some idiot to have slammed in a post that was too big to begin with.
4) You can also go down one size in seatpost and see if that is the correct size. If it's too small DO NOT USE it.

PUT THE HAMMER DOWN

seedubs1

HAMMER!
But seriously, I agree with the guy above me. That, or cut it. 9" is plenty enough. No need for more seatpost in the tube than that.

thedips

finally some good advice... i was wondering how far i had to read before i would see REAM THE SEATTUBE properly...

even though you cant feel it.. it still might need a good reaming (thats what she said... i know) ....
same thing with my colnago which was driving me nuts for a few days before i finally just took it in....

subsistbmx@hotm

9" is more than enough, personally I always cut my seatpost down to not carry any extra weight. If it's it a good 4" it should be fine but I'm not a professional but this has worked for me over 5 years now.