Join Date: Oct 2004
Bikes: Cannondale CAAD10 Team, Giant TCR
Most saddles have 7 mm round CrMo or Ti rails that fit almost all saddle clamps. There are some carbon rails that are 7 mm round, but most are oval 9x7 mm that only fit on top clamp types, but not on side clamps. Ritchey does sell side clamps to fit the ovalized rails though.
Care must be taken when installing carbon railed saddles and ensure the clamp bolts are torqued to spec. Too tight and you risk cracking the carbon. Full clamps are better on carbon than the minimum yoke-cradle types because it spreads the clamping forces on a larger portion of the rail. With the yoke-cradle types, the forces are focused only on certain points along the rails producing stress raisers, and produces a "bowing effect" on the rails if the bolts are overtightened.
As for the saddle width, it is usually at the widest part of the saddle. But again, it may vary from manufacturer to manufacturer.
Last edited by e_guevara; 07-29-14 at 08:06 PM.
Reason: Additional info