Bagby - an interesting departure....
With four up in our 172, I backtracked to the very start of the (downhill) runway. About 1/3 of the way along the (downhill) runway is a tarmac road running right across the runway. As the grass gives way to tarmac there's a drop down, and with the aircraft close to flying speed this threw us momentarily into the air, only to come back to earth heading towards the runway edge as we hadn't reached VR yet.