Bicycle Mechanics - Seat Tube Shrunk?

Got a new saddle for xmas. I need to readjust the seat post's height. Went to take off the seat post and couldn't. It was hard to budge. I could move it back and forth about 2 inches and could pull it up about 1/2 inch, with a lot of elbow grease. I know it wasn't sticking metal-to-metal, 'cuz I can move it back and forth.

I gave up and took to the LBS to see with they can do. I was lucky that there was a guy there that was twice my size. After huffing and puffing for 15 minutes, he was able to pull the seat post off. Man, I was tired and sweating from the ordeal.

Anyway, installed the new saddle that I got from xmas and went to insert the seat post and could barely get it into the seat tube. I was able to force it in about 1cm. My wife's bike had the same seat post (27.2), so I try inserting mine into her bike and it went in fine. So, my seat post is fine, it's my seat tube that has shrunk.

I'm wondering what happened to my seat tube. Did it shrink? Did I tightened it too much in the past that now it won't open up? I placed an order for a 27.0 seat post. I thinking this should be fine, eventhough my seat tube takes a 27.2. But what can I do, the seat tube has gotten smaller. Is it ok to use 27.0 seat post on a 27.2 seat tube? Or is there a way to get the seat tube back to be able to take a 27.2 seat post?

i would guess that maybe it took a hit during a fall, and the dent is too slight to see, but enough to make the seat stick. Just a thought.

No crashes or falls on the bike...yet! :)

It might be overtightening. You may have crushed the post and frame in so that pulling out the post is difficult and the opening is now permanetly smaller.
I'm not sure but I think the 27.0 would be fine. I'm tempted to say to try and wedge the opening wider but I don't want to risk damaging the frame.

Steel frame, aluminum post? It may not have siezed yet but may be well on its way. Hone out thye seat tube just a bit. Or maybe your seat tube is bent?

Could be a sudden weather change causing it to contract.

My thinking is with RacerX. I think I've overtightened it and it's permanently smaller now. I try "prying" it out a little, but didn't want to do anymore damage to my Specialized S-Works frame. I'll try the smaller seat post and hopefully it will be ok. I'm also hoping it's the weather, but this is wishfull thinking.

Put a little grease on the seat post and the post tube. Use a mallet to tap the seat post into the post tube.

If you ever have to take it out again and it is still tight; keep the saddle on the seat post, sit down and straddle the bike in front of you. Put one foot on the down tube, one foot on the chain-stay. Grab the saddle, pull, twist, grunt, and it will come off.

That's exactly what I did to get it off, but wasn't strong enough. Had to have the big guy at the LBS do it for me. Don't want to go through that again.

It doesn't sound like there a problem with using a 27.0 on a 27.2 tube (atleast no one has said not to). So, I'll give that a try.

Originally posted by EagleEye
That's exactly what I did to get it off, but wasn't strong enough. Had to have the big guy at the LBS do it for me. Don't want to go through that again.

It doesn't sound like there a problem with using a 27.0 on a 27.2 tube (atleast no one has said not to). So, I'll give that a try.

It's not likely that 0.2 mm will give you enough slop to put you at risk. If it works, it should be O.K.

You could have accomplished that much with some metal sanding paper, some water, and about 15 minutes of elbow grease.

Got my new 27.0 seat post yesterday and it fit it snuggly. The seat post seam to fit perfectly, so I guess the tube did get smaller. I didn't over tighten it this time. :)

Originally posted by mike
Put a little grease on the seat post and the post tube. Use a mallet to tap the seat post into the post tube.

Inserting a post with a mallet is a good way to never get itout again.