Slipping seatpost...
- Thread starter Triphop
- Start date
Are you using a bolt or a quick release?
Is the clamp brazed onto the frame or is it a seperate clamp? Are you sure it is the right size?
IF it is the right size, try 'knurling' the post. Knurling involves displacing some material to essentially give it a larger diameter, much like a stem/handlebar interface.
make sure that the "cut" in the clamp lines up with the "cut" in the seat tube, so that it can squeeze the seat tube walls better.
Also make sure you're using the right size post.
Also make sure you're using the right size post.
Thanks for the feedback, here is some more info.
It has a clamp, the stock clamp that came with the frame (SC Chameleon). It is a Ritchey post.
-I greased the post
-The post is the correct size of 30.9mm.
-The "cut" of the clamp and seat tube lineup.
-It is clamped down as tight as possible. Any tighter, I am afraid I will break or bend something.
I have no idea how to "Knurl" a post, how do you knurl? Would knurling weaken the post? I am somewhat concerned with messing with it, as I am running ALOT of post due to the sloping nature of the top tube, the post flexes nicely as is.
This is what I was thinking, clean out the seat tube, rough up the seatpost with sandpaper, regrease and clamp that summabitch in there tight. Sound good?
It has a clamp, the stock clamp that came with the frame (SC Chameleon). It is a Ritchey post.
-I greased the post
-The post is the correct size of 30.9mm.
-The "cut" of the clamp and seat tube lineup.
-It is clamped down as tight as possible. Any tighter, I am afraid I will break or bend something.
I have no idea how to "Knurl" a post, how do you knurl? Would knurling weaken the post? I am somewhat concerned with messing with it, as I am running ALOT of post due to the sloping nature of the top tube, the post flexes nicely as is.
This is what I was thinking, clean out the seat tube, rough up the seatpost with sandpaper, regrease and clamp that summabitch in there tight. Sound good?
How 'bout a shim of some sort...like that thin rubber strip that you get with lights that clamp to the handlebar. It would take some workin', but squeeze that little summumma in there and I'd think it should hold it, no?
you could try cutting a strip of metal off of a beer can. I have heard of people doing that.
DING DING DING!!! We have a winner!!!!
That is exactly what to do. Make a shim from an aluminum can...preferably a beer can (no reason). The can is optimal thickness for shimming seat posts, worked great for my azonic eliminator.
Any decent shop will have a Stein knurler. Mark your post at the clamp point, to give reference for knurling and take it in. It will only take a few minutes to do.
knurling works in the case of a worn post/seat tube... if it's not worn (you would normally feel it) I'd just say it's the clamp.... it sounds like it got stretched out. the gap in the clamp, has it all but disappeared? are the faces inside the gap still parallel or do they form a v?
Sounds like a new bike. I think last years Chameleon had a 27.2 post size. Fist thing to try is less grease. But also look at the clamp carefully to make sure the bolt or clamp is not "bottoming" out and not clamping tightly enough. The gap on the collar and the frame slot do not have to be lined up. In fact, some carbon post manufacturers, Campagnolo for one, expressly recommend having the collar gap on the oposite side of the slot in the seat tube. You could try doing it that way just to see. I have a very large riding buddy who had the same problem. But he fixed the chronic slippage by using less grease and not cleaning the post and seat tube every week. He also rode a Chameleon but with the 27.2 post. If all that fails, take the bike to the shop and have them measure the seat tube and post to make sure they are up to spec. If something is out, then you can get a new post or have the frame warranted or shim.