I'd like to use my ramp as a patio. Is it safe to just put some jacks under the rubber bumpers? I load 980lbs bikes with that ramp so it should hold 3 or 4 adults, no?
if you can find the structure you should be fine. Like you said heavy bikes roll up it supported only by the lip/bumpers and the hinge. You should be fine for 3-4 adults, as long as they're "normal" size.