These ramps are ultra light duty and poorly designed. The cross bars are spaced so far apart that driving a lawnmower up the ramps is like riding a bucking bronco.
The two flimsy strips running up the ramps are light duty plastic. May help with an unloaded wheelbarrow but little else.
Going to have to add my own plywood runners - more expense on my part.
Summary - look elsewhere if you what to use these for loading any wheeled vehicle sucks as a riding mower or ATV.
Fantastic purchase! I shopped around for a ramp for a bit, a little hesitant about spending that much for a ramp sight unseen. However, it worked great! Strong and sturdy, got a sled into the truck with no problems. Just an fyi...its a slippery ramp. Be super careful walking up and down on your feet!
Thomas Motes 
