Q: What clamp design is best for my saddle needs and how tight should I torque everything?
A: The connection of the seat to the seatpost is one of the most overlooked areas on the bike. Saddle makers use everything from steel to carbon on their rails, and post makers all use different clamp mechanisms. The good news is most seatpost clamps are designed to work with the standard seven-millimeter seat rails or the oversized eight-millimeter rails, which is good since there isn’t any set industry standard. So basically seat selection comes down to comfort, price, and weight.
As for torque, it all depends on the material used and every manufacturer has their own spec. If carbon, you better seek out this torque, but if it is a titanium or chromoly, then tightening enough so the seat won’t move (without over-tightening to the point where it is hard to get off) is the key. Nuts and bolts tend to tighten even further when under stress so some anti-seize or grease will go a long way on the hardware (never use on carbon).
As for clamp design, two bolt systems tend to be more stable than single-bolt systems and require less torque. If you buy quality parts, than slippage won’t be that big of a concern. However, if it is a cheap bike/parts, than investing $1-2 at the local hardware store for some higher quality hardware will serve you well.