General Cycling Discussion - My seat keeps slipping down!

Is there any way to fix a bike seat that keeps dropping about an inch every time I ride? This is pretty annoying and I suspect it might be what makes my knees feel a twinge, too.
I'd prefer not to buy a new post since it's an older bike and I am thinking of replacing in a year if I am still mildly biking obsessed.
?????

Cut a piece of soda can as a shim. :)

If you have a quick release seatpost clamp, try a bolt-type. I had this problem on a hardtail and replacing the clamp did the trick.

I 2nd the soda can idea. It's worked for me.

Mine seat keeps slipping down, too . . .

I've written it off to middle age. . . Oh, you mean your BIKE seat. . .

(The preferred aluminum can to use for a shim is a beer can; cq: "Zen and the Art of Motorcycle Maintenance.")

I just solved this problem on my bike. I tried all sorts of ideas, a couple of different seatpost, collar, and bolt combinations; and a couple of different beer can shims, all with the help of the wonderful guys at Bike Source in Columbus. The only thing that was working was riding my 15 mile rt commute standing up.

What finally worked was carefully cleaning all of the grease off the post and seattube with rubbing alcohol and then rubbing dirt (nice ohio clay fact) over the tube. No slip since.

The mechs at B.S. suggested that once or twice a year I free the post and move it slightly, although this was the very last thing I tried so if it does cold weld at some point I'm no worse off than I was before (and it will still stay set at the correct height). Of course YMMV

If you have a quick release seatpost clamp, try a bolt-type. I had this problem on a hardtail and replacing the clamp did the trick.

+1

I had the same problem (and solution) too.

What if you bought a brand new Thomson Masterpiece seatpost, used it and when you get a new bike, put the Thomson on it?

I like the shim idea, but the first thought I had was a pipe clamp on the post (covered in duct tape of course!)

What if you bought a brand new Thomson Masterpiece seatpost, used it and when you get a new bike, put the Thomson on it?

Because different frames require different size posts. Also the Thomson may require a shim too. Mine does.

The Thompson (elite is all I could afford) has very fine stirations around the length of the tube. That could help - I haven't mounted it yet.

I fitted my other bike with a Salsa bolt type clamp and the problem went away, and am still keeping a little grease on the seatpost.

if the shim doesn't fit then try putting loctite between the seatpost and the seattube

First of all make sure you have the right size seatpost.
Second get a bolt on seat post collar.
Third go to a bike shop and ask for some of the grease that comes with some seatposts (I know FSA ships it) It is a gritty grease that you put on before installing the post.
If that does not work go with some sand on the grease.

I am heavy and I have had this problem before, interestlly enough the Thompson which has the lathe cuts so it should stay up was one of the worst post I had for slipping. I hope this helps.

A common problem with carbon frames and carbon seat posts. In that situation a dab of "technical grease" solves the problem. I truly does work as advertised.

http://www.tacx.com/producten.php?fl=true&language=EN&lvlMain=18&lvlSub=66&ttop=Maintenance%20Tools

I've now tried alcohol, toothpaste (!) then spit and dirt. So far so good. 2.5 bumpy miles w/ no slip (sorry, but the toothpaste alone didn't work at all).
But I'm taking her in for a tune up on Sunday and I'll see if they can do the right thing w/ the mechanics grease.
all useful advice. Thanks everyone.

I am heavy and I have had this problem before, interestlly enough the Thompson which has the lathe cuts so it should stay up was one of the worst post I had for slipping. I hope this helps.

Thanks. Thanks ever so much for filling me in on my new but untried thompson.