Seatpost Slippage?

[LoboDelFuego]

I just got my new(used) frame built up. It is a 2001 Enduro FSR, built with all the parts from my 2001 Rockhopper Comp Disc. The specialized catalog for that year says that both bikes use a 30.9 x 400 mm seatpost, but even if I tighten the qr to the max, the seatpost on the Enduro still slips around from side to side and gradually sinks lower. what can be wrong/how can i fix it?

[golgiaparatus]

you sure seatpost and clamp are the correct size? If so check seatpost for serious wear, if fine check frame for crack, If no crack go for the shim (coke can shims rule :).

[oldfart]

It could be the qr is bottoming out on itself and not clamping the post tightly enough. Check that first. maybe try another qr or a bolt on clamp just to see.

[LoboDelFuego]

I tapped the QR off with a rubber mallet, and it turns out is was cracked. ahh who cares i have another one lying around somewhere.