The 3t ionic 0 team seatpost ionic is a new seatpost design featuring the sophisticated and robust 3tndashexclusive difflock seat clamp ionicndash0 places the seat clamp assembly in line with the seatpost for zero setback many athletes seeking outright speed favor this more forward position on the bike some frame designers are also specifying a slacker seat tube so riders can set their bike up with an inline post which is lighter than a setback post the splined alloy diffloc