I saw the topic title and I almost shit my pants. You dont jump metal ramps with 4 wheelers unless you are planning on getting some major air, and doing backflips oh wait....seriously though, you need to learn on dirt first, get a mound of dirt, pack it down real hard, get another mound of dirt to make a landing, pack that down real hard, and there ya go. I used to ride bmx a lot so I used to have to build dirt ramps and stuff, great fun. And try not to kill yourself too. And above all else, have fun.