How do I change the seat?

I got a new bike and wanted to put my old seat on it, I figured I would just take out the whole seat with the pole that you raise and lower for seat adjustment (sorry I don't know any of the correct names :o ) the problem is that my old seat has a much slimmer bar and doesn't fit into the new one. It didn't look like the seat came off of the bar without some major tools.

Any advice?

Did you buy a new seat and seatpost (the "pole")? Seatposts are made in different sizes. You should have the tools to change the seat anyway because these are the same tools needed to change to fore/aft position of the seat.

Without knowing the type of seat (saddle) you have, we can't give much recommendation. Can you give that info?

If you could post a couple pictures, that would really help too.

Probably all you need to do is switch the saddles. The seatpost for your new bike stays with your new bike, but you take off the new saddle and put your old one on instead.

Usually you only need one tool. (an allen wrench) But we'd need to see what you've got to be sure.

Here's a very good overview by Sheldon Brown. Further down the page he talks about the clamps and such holding the saddle to the seatpost. http://sheldonbrown.com/saddles.html

I'm gonna go check around for one with more pictures, I'll be right back.

Edit: well, I'm not finding good pictures. Phooey.
Basic idea, look at the assembly where your saddle rails meet the seat post. Probably there are two pieces of metal (like a clamshell) holding the rails between them. There is probably a bolt holding those two pieces of metal together and making them pinch the rails.

Loosen that bolt (probably with hexagonal allen wrench) until you can turn the top piece to right angles with the bottom piece. Now it looks like an "x" instead of a clamshell.

The rails are free, and you can just lift the saddle off the bottom piece of metal. (the bottom of the clamshell)

Now you have a naked seat post! :eek: (congratulations!)

Put the replacement saddle on the bottom clamshell, making sure the rails are both in the little grooves or whatever (if the bottom clamshell has grooves). Turn the top clamshell so it lines up over the bottom one again, and tighten the bolt so they come together and hold tightly to the rails.

Loosening the same bolt just a little will let you adjust the fore-aft and tilt of the saddle. Sheldon Brown's site (the link above) covers that pretty well, but if you have any trouble come back here! Lots of good folks on TE who are a great help on all kinds of subjects!

Was your new bike fit for you? If so, make sure you know your leg extension and fore/aft before swapping the saddle.

To measure your leg extension, place a clipboard on the saddle. Measure from the bottom of the clipboard to the center of the bottom bracket (that's the center of the crankarm -- the lever that attaches your pedals to the bike).

Then, measure from the nose of the saddle to the center of the bar.

You'll want to match these measurements when you put your old saddle on the new bike. This will ensure that your fit is still correct, especially if the two saddles are different (ie one is thicker than the other).

Thanks for all your suggestions. Now I know those poles are not a standard size! How frustrating. The new bike was not fit for me - it is just a used bike I got on Craig's List- and the old saddle is from my old bike. It didn't look like it came off with an alan wrench, it seemed like the way it came off was with a giant bolt. I will try and take some pictures. Thanks!