Sliding Seat post??

boffa said:

Has anyone got advice for how to stop the seat post from sliding down...mine is carbon fibre and other bike has an alloy one?

They are on Mountain bikes.

Try a HALF-shim cut from a soda can, first ... THAT has worked on one seatpost I had which was constantly slipping (a half-shim is alll that would fit in the particular frame) .

On ANOTHER/older frame which I thought was supposed to use a 27.0 seatpost, I finally resorted to a (slightly over-sized?) 27.2 seat post to resolve the problem ... perhaps, 27.2 was the correct size!?!

my salsa seatpost on my giant team once road bike is slididng down too.
the post is a snug fit so there might not be space for a shim or tape there.
the collar bolt is already very tight and tightening it more could snap the bolt or strip the theads.
i could try roughening up the surfaces with sandpaper but that will ruin the nice surface of the seat post. Other suggestions are hairspray or tape but i dont want to use those.
my seatpost is very long, i wonder if cutting it down will solve the sliding problem. the clamp and seat tube might grip the shortened post differently.

some guys at a mountainbike forum solved thier sliding problems by changing to a slasa seat clamp. the seat tube clamp they used is a lot beefier looking than my clamp in the picture and requires no tools to open/close, but it isnt as pretty as my clamp here.

[quote="boffa"]Has anyone got advice for how to stop the seat post from sliding down...mine is carbon fibre and other bike has an alloy one?

Do you have to adJust your seat height often or does it stay at one setting?,
if it does,and you have a closed type downtube,slide a wooden dowl stick,into the seatpost and size it into the right height.This will share the load on the locking clamp.Ok so you'll gain a couple of grams but your saddle will stay ay the correct height.

[quote="HowardSteele"]

boffa said:

Has anyone got advice for how to stop the seat post from sliding down...mine is carbon fibre and other bike has an alloy one?

Do you have to adJust your seat height often or does it stay at one setting?,
if it does,and you have a closed type downtube,slide a wooden dowl stick,into the seatpost and size it into the right height.This will share the load on the locking clamp.Ok so you'll gain a couple of grams but your saddle will stay ay the correct height.

boffa said:

Has anyone got advice for how to stop the seat post from sliding down...mine is carbon fibre and other bike has an alloy one?

They are on Mountain bikes.

Since I got my new bikes I do not have those problems anymore.
But one thing I do, I got one of those relectors that clamps to the seat post.
I slid it right to the bottom, it ain't much but seats stay put. Tweenst that and the regular clamp, its good, I lost 35 LBs too, that could help.

[quote="HowardSteele"]

boffa said:

Has anyone got advice for how to stop the seat post from sliding down...mine is carbon fibre and other bike has an alloy one?

Do you have to adJust your seat height often or does it stay at one setting?, if it does,and you have a closed type down tube, slide a wooden dowl stick, into the seatpost and size it into the right height.This will share the load on the locking clamp. Ok so you'll gain a couple of grams but your saddle will stay at the correct height.

I used a piece of pvc once in an emergency

I bought a Greenzone 20" folding bike, and having the sliding seatpost problem. This solution will NOT work on my bike cause the seat tube is welded to the side of the area where the pedals and cranks are and is open on the bottom.

If your seat tube is closed on the bottom, a simple solution to TOTALLY eliminating seat post slippage is to put an ADDITIONAL seatpost in the tube (with the small flare pointed down). Getting a seat post a little smaller will allow it's easy removal if you want. Doesn't HAVE to be a seat tube- any aluminum tube cut to the right length will work, as long as it's close to the same diameter. Think of this as being able to buy a "full-length" seat post!

For my open ended tube, I plan to drill holes in the frame and put a tempered bolt thru it, horizontally, to be my seat tube "stop".

Hope this helps everyone with this problem!

I'd love to hear people's comments on this-

Rusty
Dayton, OH
Home of the Wright Brothers

Looks like someone already posted a similar suggestion, with the wooden dowell solution. Congrats on the weight loss- that's why I bought my bike!

In the picture it looks like the slot in the tube is closed up
completely, Maybe just a bit of filing to open up the
slot a bit?

Or am I seeing it wrong?

[IMG]cyclingforums.com500Open ↗[/IMG]

once i just kept tighting it once and again, after all rides, until it eventually stop sliding,
i bought different replacement clamps but ended up not changing it,
a tape marks the seat post height 1 or 2 cm above the clamp to keep an eye on it constantly,