carbon seatpost slipping

[Climb01742]

the campy record carbon seatpost i'm using on my new parlee keeps slipping down during a ride. steve hampsten said others have had the same thing happen. steve suggested using super fine sandpaper to scuff up the seatpost a little and the inside of the seattube, which i did cautiously. i also swung the seatpost clamp 180 degrees, so the bolt is in the front. but the post still slipped again today. i'm careful not too overtighten the clamp, but get it as tight as seems safe. any other suggestions? i haven't had the same problem with carbon seatposts and non-carbon frames. i'm guessing the carbon post-carbon frame interface isn't grippy enough. i may just swap a DA seatpost from a ti frame, and use this carbon post on the ti frame. open to other suggestions. thanks.

[zap]

are you using the campy supplied clamp?

did you check the dia. off the post?

did you check the dia. of the seatube?

and, your not using grease. correct.

[Climb01742]

zap, i ain't the sharpest knife in the drawer, but no, no grease. :) and the clamp is the parlee spec'ed clamp. the diameter of seattube and post are spot-on, nice and snug. should i try a campy or other kind of clamp? i have four other carbon seatposts -- campy, bontrager and two dario spec'ed italian jobs -- and none of them has ever slipped. so i'm a bit mystified.

[zap]

try a correctly sized campy clamp. its an offset design. follow campys torque specs.

Did you check the dia. with a caliper? also check for roundness where the post meets the clamping area of the seat tube.

if you havn't done so, clean all surfaces with rubbing alcohol.

[Steve K]

Zap has it. If the diameter specifications are correct. Then use a clean rag with Isopropyl rubbing alcohol and clean the post and inside of the seat tube. Let it dry out and don't touch the cleaned surfaces with your fingers. Tighten up... Good luck.

[dave thompson]

A little powdered rosin inside the seat tube will work just fine to retain your post.

[slowgoing]

Climb - I had a campy carbon post for a while. I finally did unwittingly overtighten it. Boy was it a scary sight. The carbon cracks and comes off in very sharp shards. Won't buy one ever again. I recommend the chorus titanium post. Same clamp and setback as the record, but you can tighten away all you want. Very litte weight penalty either, if weight concerns you.

[Kevan]

on the post and and inside the seat tube never ever touching those surfaces with your hands will reinserting the post. I like Dave's suggest about using rosin hmmm...

[Climb01742]

A little powdered rosin inside the seat tube will work just fine to retain your post.

dave, where can you buy rosin? i've only ever seen it on a pitchers mound. :rolleyes:

[Blastinbob]

Someone said something about using toothpaste. I used the sandpaper method on my Calfee, which was successful.

[BumbleBeeDave]

. . . I think blastinbob has it--but with a few more steps necessary. Sandy gave me this advice originally and I’m sure it will cure your problem permanently . . . You should sand your entire carbon frame with medium grit sandpaper. Then, while wearing black socks and eating a tuna sandwich, rub the entire frame with the rubbing alcohol. Then you will need to lean your bike against a post at such an angle that it repeatedly falls to the ground. But be sure to save about 12 ounces of the alcohol to drink after you see what my (Sandy’s!) advice has caused you to do to your bike. ;) :rolleyes: ;) :crap:

BBDave

[dave thompson]

dave, where can you buy rosin? i've only ever seen it on a pitchers mound. :rolleyes:
I think most any good sporting goods store would carry it. It's also used in weightlifting circles.

[slowgoing]

If by rosin you mean the chalk that weightlifters and gymnasts use, I would think that would only be a temporary measure until the next time the frame got wet.

[John H.]

How about using beeswax?

[quattro]

Climb, this may not be the answer you are looking for, however, I use the USE Alien carbon post on my Parlee and I have never had a problem with it slipping. I also use it on my IFCJTI with no problems. The major stink about the USE seat posts is the two bolt head. Well, when I was at interbike I saw the new USE one bolt head. I'm told it should be available next month(December). The post is one of the lightest carbon posts available, with the new one bolt head it should solve all of the mounting problems people seem to have with the present head. If you don't solve the slipping problem with the Campy post, give the USE a try. Regards

[EdK]

A little hairspray on the post before installation also works. Smooth campy post plus smooth carbon seattube = slip!

[victoryfactory]

Some very good suggestions.
It seems to me that if you sand the inside of the seat tube/ seatpost clamp
area rather than the carbon post, you would get increased friction without the danger.

VF - I live for danger....

[vaxn8r]

I tried every one of those tricks on my Calfee/Deda post. I even went as far as getting the distributor to get me a new one. Nothing worked.....until I switched to an aluminum Thompson, which works perfectly :)

FWIW I could care less about the CF post, but it did look cool :cool: :cool: :cool:

[Climb01742]

carbon on carbon is tough. thanks everyone for the ideas. i'll try 'em...if nothing works, i'll just switch carbon post to metal frame and switch a DA post from a metal frame into parlee. here goes nuthin'....