Slammed
As in "Whoa, you're running that seatpost totally slammed, dude".
What, you mean, as low as it'll go?
Slammed should only ever be used to refer to a crash, as in:
"Good bike ride, darling?"
"Yes, thanks, the only thing which spoiled it was when Pete slammed and had his anus smashed in by his very low seatpost".