I started out with 2X12's and a home made lip on the end made out of angle iron. They worked ok but I, also, would hang up at the break over point when I went over into the pickup. When I bought a new mower a few years ago i also bought a new set of arched ramps and haven't looked back. I vote arched. When I load it on my flat bed truck I have to get creative due to the bed sitting higher than a normal pickup bed.