FSA K Force

sirdjango

i have an FSA K Force SB25 single bolt seat post. the problem is the seat clamp always loose when i run thru potholes or uneven road. i notice that the clamp is not gripping the saddle rail hard enough even i've tighten the bolt quite hard. has anyone face this promblem? or can i change the clamp? i'm 75kg by the way...