Carbon Seatpost woes AGAIN

mjhiow

Hi everyone can anyone help here i'm getting increasingly annoyed here....

I'm on my second spesh carbon seatpost for my full carbon Spesh Roubaix and after damaging the first out of my own stupidiy of not reading the instructions and having the clamp in the wrong position (and splitting the post), a similar thing is happening again...

My second spesh post has be installed to the letter of law regarding the frame slot position being opposite to the clamp bolt etc AND i am actually UNDER TORQING the clamp (about 6.0Nm) so it just avoids slippage. At the weekend when I took it out for a regular clean and inspection I was horrified to notice the outer carbon is being slightly pinched again. These are quite thick carbon posts and i'm certain it hasn't gone though but it doenst look great either....

My LBS, which I took the post to for an opinion, saia it may be a problem with an edge on the clamp, but they would feel happy to ride with it the way it is?????????

I am just a little worried as I dont want to imagine the result if it had a total failure........... :shock:

Does this sound familiar to anyone else?????????????????

Please help............

rubbernekker

6Nm is still quite high for a seat post, do you use carbon fibre grip?

There may be an issue with the clamp or the slot- 2 posts being faulty isn't likely.

mjhiow

Cheers rubbernekker

Anything less than 6Nm and it slips, the recommended it 7.2Nm!!! The first post was my cock up anyway but can you enlighten me to carbon fibre grip please???

Many thanks...

Wheelspinner

I know of two types of the carbon "grip" paste. One is made by Tacx, and the other is a Ritchey product. Both look a little like a grease, but have a fine grit in them (rather like toothpaste in consistency really) which helps stop slippage in clamped carbon joints. The stuff allows you to use lower torque on bolts and still get solid no-slip results. Excellent stuff.

This is the stuff from Tacx.

ALso, CRC do the Ritchey one and the Tacx stuff too.

mjhiow

Many thanks Wheelspinner. Just ordered some...!

Wheelspinner

Welcome! Hope it helps. I'm surprised the recommended torque is 7.2 Nm - that's high for a carbon fitting. I don't use more than about 4 on any of my carbon frames, whether the post is carbon or alloy.

ugo.santalucia

The short answer is get a refund and stop boying carbon seatposts. They are not any lighter than alloy ones and if they break under 6 Nm torque, they are rubbish. My middle finger would probably survive that torque, but I wouldn't sit on it

hulla the hulla

the clamp on my alloy frame, carbon seat posted Trek says up to 9Nm !!