friction paste, of you don't have it, you could use toothpaste...

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Also be very careful tightening the seat post clamp only to spec with a torque wrench. They've had problems with the frame cracking in that spot (usu toward the rear). Check to see if that's already happening.

Have you had this bike for a while or did you just get it? What model year is it?

X2 with the seatpost tightening. I think it has a 10nm rating but mine cracked at around 8.5 while tightening.

I'd stay well clear of of that so called 10 Nm "spec." I tried to take mine over 5 Nm once and noticed the torque curve flattening (aka, plastic deformation)-- never again. I now only go to 4 Nm max and have not experienced any slipping. I believe at 10 Nm it would have busted out the backside of the seat tube. Note: I'm using the UCI post with the adapter wedge, so my results may be different.

For mine to hold, I have to go to 7 or 8nm. At 7, it was very slightly slipping on the rough roads in New Zealand.

I agree, 10 is a bad idea.

This may be stupid, but if there is enough room, I put a shim in between the seatpost and frame. I learned this trick on ST from the old Cervelos. People would cut aluminum cans and use that to make the seat post just a tiny bit fatter. I definitely wouldn't torque that thing down much beyond the spec.

Friction paste first if you haven't used it. I think it's required for carbon seatpost+frames due to the problems with overtorquing.

Others are throwing torque specs around and I just want to add some clarity to this.

There are two different versions of the P4. The two can be easily distinguishable by a space between the integrated water bottle and the frame.

- The 1st generation/version had no space between the downtube and the bottle (see below). The max torque spec on this is 7nm. It seemed to be problematic for more than a few people.


The second generation P4 had a larger cut-out area for the bottle (there was a bigger gap between the down tube and the leading edge of the bottle). The reason for the modification was to allow enough space to mount a standard round bottle if desired. The seatpost area was beefed up and the torque spec increased to 10nm.


In both cases, it's a lot of torque and used to cause me a bit of fear to touch the seatpost on my 2009 P4.

However, a few years ago I switched to the "UCI-legal" P4 seatpost, which is a smaller post and comes with a shim to make it work in older carbon P2/P3/P4. It seems to stay put in my frame at far lower torque specs. Maybe the shim does a better job of keeping it's shape and not deforming / slipping under load (?).

...and always use carbon paste!