If your bike has a saddle with a carbon rail, the dimensions are usually 9 x 7 mm, which differ from a regular 7 x 7 mm saddle rail. This makes it possible, if your saddle has a carbon rail, to use seat posts that clamp the saddle only on the top and bottom of the saddle rail. If the saddle is clamped onto the rail all around or from the side, you may damage the saddle if it has a carbon rail. For most seat posts, a specific saddle clamp for carbon saddle rails is available in this case. When fitting carbon parts, always use a torque wrench and apply the torque indicated on the saddle in Nm (torque in Newton metres).