Road Cycling - Opinons on Campy record carbon seatpost?

I am about to buy it new from a guy for $50 only. The only thing is it is 27.2 and my frame is like meant for 27.0. I tried to fit it in today and it works.

I was reading the reviews on it at roadbikereview, they were very mixed. People said that it was relaly weak. I don't think that will be a problem for me. I weigh only 155 lb.

Opinions?

I have heard people talk about flexing seat posts and personally think it's all crap. I have a Giant CF seat post which is brilliant, I have never noticed any flex. If it's good enough for the Pros, it's good enough for me. I am a similar weight to you, so you won't have any problems.

CHEERS.

Mark

Well, not that ALL carbon posts are weak but specifically campy carbon posts. Or at least that's what i got from roadbikereview.com

Anyhow, i think i'm goign to jump on it. I'm not paying anywhere full price for it, plus i scratched it today putting it in. I feel obligated to get it :)

Get it. I'm a big fat bastard at 260 and I have a cf seatpost on my Allez. I haven't broken it yet.

two things:

1) don't fit a carbon post into frame if it's not the right size. the additional compression can weaken the post making failure more likely

2) If you've scratched the post badly I would suggest you pay the owner his $50 and then bin the post. It will more than likely fail. if it breaks and it punctures your O-ring, you'll be cr*pp*ng in a collostamy (?) bag for the rest of your life.

for a 27.0mm seat tube, get a 27.0mm carbon seat post. Not bigger. Smaller you can shim to size.

oh god! Man, TimB don't scare me. It can't be that bad. What if just tightened the clamp less? The way i figure it, if it's tight going in already, i just have to tighten it less. The end result will be the same amount of pressure on the post.

right? OH GOD A COLLOSTAMY BAG FOR THE REST OF MY LIFE LOL SUICIDE.

tightening less is not really an option because;

a) you're stretching the seat tube material slightly which is not too bad

b) you're compressing the resin of the post which can cause mico cracks int he resin. These cracks get larger and then the post breaks.

I'm not trying to scare you! The carbon manufacturers recommend a certain tightening torque so that you don't exceed the allowable compressive stress in the reisn. Baring in mind there is a factor of safety involved, I would still be hesitant to say to you that it's ok.#
My advice to you is leave it and find the sorrect size post.
There may be some people who will disagree with me on this but with carbon posts I would err on the side of caution.

This is my advice

D'oh. I bought it. It looks really really nice, it's very light. About 3mm thick.

Well, it fits in, just really snugly. TimB, i don't understand how it would be any different than if i had frame made for 27.2. Wouldn't the resin compress anyway, if i torqued it too much?

I think i'm just going to tighten it just enough so it won't slip. Hopefully it won't break.

The other thing is the finish scratches REALLY REALLY easily. Each time i put it in, it scratches the bottom of the post.

I agree that if major scratch in it, don't use it if small surface mark (cosmetic) I would not worry about it. If you have a accurate caliper I would measure the seatpost and the ID of your bike's seat tube. A while ago I got a 27.0 seatpost it is actualy 27.18 and original seatpost is 27.2 so I used it in my bike no problem, it is a Ti seatpost though and is snug but not tight fit in the frame.

It's a small surface scratch, oh well nobody will see it anyway. I'm just scared, i don't want the post to suddenly break and stab me in the ass.

Phat,

you may have a bur int he seat tube thats scratching the seat tube. remove the seat tube and clean out the bur.

As long as the scratch is not deep and 'V' in shape it should be ok but inspect that area for cracks regularly.

As for the post being being over size for the hole, if the post goes in without to much trouble even though it's size is given as 27.2 it may be that you struck it lucky and received a post that is under the tolerance.
if the fit was very snug and you tighteed it up you would have already preloaded the carbon tube as various point and when you tighten you can exceed the allowable clamping pressure even thought he bolt is torqued correctly. This is why the manufacturers instructions are very explicit wrt tightening torque and leaning the seat tube properly and degreasing before installation.

Well, what if it's snug but i DONT tighten it to campagnolo's specs? I was going to tighten it just enough so that the post would not slip with my weight on it. I figured that would be within the posts tolerance, don't you think? i dunno, i guess there's only one way to find out...

as long as the pressure is uniformly distributed around the circumference then I would agree it's probably ok.
It's if you have tight spots that I'm worried about. Thw way the tube is designed and manufactured, hgh spots in the clamping pressure can still lead to te allowable presure being exceeded under dynamic conditions ie with you on the bike and bike in motion.

Like you say ione way to find out. If you careful it should be ok but remember what you're doing is not recommended practice.