Clydesdales/Athenas (200+ lb / 91+ kg) - Sliding Seatpost

I got a new bike today and of the few bikes I have owned I have always has a sliding seatpost problem. The seatpost came with the frame and I have tightened the bolt about as much as I want to. Anyone got any tricks to keep it in place?

You mean it slowly goes down when you're on it? Can you move it just by applying pressure without sitting on it?

Slowly yes...I have to ride it for it to happen..

you need to get a seat binder. It will tighten the seat down much better.

http://www.excelsports.com/thumb75/Campagnolo%20Seat%20Post%20Clamp.jpg



Its got what appears to be a pretty good one...it has the little slanted slit in the back...It looks like the above picture....

I had this issue before and found I was not tightening the collar enough. I had to use an allen wrench to tighten down. Maybe check with the LBS to see how tight it can go without cracking the seat post.

I once made a shim by cutting an aluminum coke can. Worked fine for me.

If your purchased the bike from a LBS I would suggest having them take a look at the problem. If not, I would take it to a LBS and ask them to help you out.

All my seatpost sliding troubles went away when I switched my collars to Surly Constrictors. Serious beefy grip. $15 a pop.

Thought I should suggest the obvious, are you sure that the seatpost is actually correctly sized for the frame? If when you loosen the collar the seatpost drops by itself it is likely too small.

Another thing to consider is if the post has been damaged at all. Sometimes efforts to keep a post in place result in crushing a portion of the post, this makes it impossible to keep it in place.

I had all sorts of sliding seatpost problems on my roadie until I went with a Thompson. They're machined with very subtle grooves that grip way better than any other seatpost I've had.

It's an expensive fix, but worth it to me.