The 3t ionic 0 ltd carbonaluminium seatpost featuring the sophisticated and robust with 3ts exclusive difflock seat clamp ionic 0 places the seat clamp assembly in line with the seatpost for zero setback many athletes seeking outright speed favour this more forward position on the bike with some frame designs are also coming with slacker seat tube so the zero setback riders can set their bike up with an inline post which is lighter than a setback post the splined alloy difflock coupling