So I bought this brand new road bike and put everything together, and when I was putting the seat on, the seat post slipped out from under the seat and got stuck inside the bike frame, like actually inside the tube itself. I have tried everything to get it out, both with WD 40 and turning it upside down etc etc.... It's really frustrating when everything was going smoothly yet this had to happen. Before I take it to a bike shop are there any alternative methods anybody could suggest, please? thank you.

I would first try to hook it with a bent coat hanger wire. Be careful not to bend the hook open so it jams in there.

Worst case is removing the bottom bracket, drilling a small hole in the shell, and pushing up with a small steel rod.

Get a star nut into the seat post and pull it out with a bolt?

If it's stuck, make sure to use some penetrating fluid (not WD-40, ATF + acetone makes a good DIY penetrating fluid.) Also could try applying heat.

I'd turn it upside down and drop it a foot on a wooden board, but failing that fashion a hook of some sort, from a steel rod for instance.

Hang it upside down and duct tape an ultrasonic resonator to it!

It may be jammed up on the water bottle boss, I would use a nail or small screwdriver through the boss to try to pry it up a few mm then turn it upside down and see if gravity will do the rest.

This was my first thought, too. The original post is a bit confusing.

If it is just a matter of the seatpost being stuck inside the seat tube, then you need elbow grease to get it out. You could clamp the top of the seatpost in a vise (bike upside-down) and then try twisting the frame and pulling.

Oh good idea I forgot about the water bottle bosses. In fact, maybe the bottle cage is installed and it's stuck on the bolt?

I'm pretty sure he's talking about a straight steel seatpost with no clamp at the top. The type that typically come on big box store bikes with a sheet metal clamp that holds the seat to the top of the post.

The only way to get that out is to hook the bottom of it with something to pull it out or some type of expander that will grip the inside of the post.

Probably 50-75% of all bikes ever made have these.

BB out? you might blow it out from the bottom



with the air compressor..




...

It's a game of twenty questions, zero answers, and a few assumptions and guesses. Such fun!

This is where I'd place my bets. Another possibility is to fish something through the bottom bracket, such as a plumber's snake.

Those posts usually have a hole in the top. If this one does, I'd just try to hook it and pull it up. Or, send a long threaded rod down through it and thread on a washer and nut through the bb shell and pull it up that way.

Where is the OP...any news to report?
Ben

What is the frame material?....if not carbon, can you put the frame upside down in a stand and simply heat up the seat tube with a hair dryer and maybe give the post binder a tap with a mallet? I would think the seat tube would expand enough before transferring the heat to the seatpost for this to work.

1. Thread a heavy duty bike tube into it with a strong nylon cord tied to it.
2. Use a pump with a straight hose connected to the Schrader valve (12v auto pumps often have straight screw on hoses).
3. Once entire tube is pushed into seatpost, start the pump for long enough to assure the tube is good and stuck.
4. Pull the nylon cord.

Never tried this but it seems possible.

OR jam one of those plumbing de-cloggers that attaches to a garden hose into seat post (if narrow enough is made). Stand back. Turn on water. I think the bike tube method has a higher likelihood of working out though.

1. set up video camera
2. remove BB.
3. insert cherry bomb into seat tube with fuse leading out of BB.
4. point top of seat tube away from living creatures, glass windows, airplanes and pinatas.
5. put on helmet, gloves, safety glasses and lead-lined suit.
6. program robot to light fuse
7. run like hell
8. watch video to see where seat post landed
9. post video on this thread.

What could go wrong?

Seat Post or pillar:

P1000590, on Flickr

Application:

1972 Bottecchia Giro D'Italia (Professional conversion), on Flickr

A lot of over-thinking - Just get a piece of stiff wire with some spring to it (coat hanger, etc.), and bend a little hook on the end, at an acute angle.
Push the wire down through the seat post, and when the little hook goes past the swaged-down neck of the post, it will spring back and grab the inside of the post - Pull up, and Bob's-yer-uncle.
Takes longer to describe, than to do ........