gsa103- Of course. My question was for those who thought that koolerb had it right, that seat rails had stated clamping pressures. Sorry I didn't make it more obvious that I knew the answer. I'll add one issue though about rails and clamps. There are different shapes of rails, some are oval, not round, and some are a larger diameter. So there is a concern that a miss match between the rails and the clamp could prove problematic. Additionally some clamps offer greater surface area of their clamping onto the rail. Some rails ask for this, less pin pointed pressure, clamp design. When in doubt ask the shop you bought the parts from if their compatible and/or go directly to the manufacturer. I've seen enough broken rails or slipping seats with miss matched rails and clamps. Andy.