Ramp.....

Going to build a ramp for when I need to load the bike onto the small utility trailer. Want the ramp to be 10' long to make pushing the 600 or so pound pig of a bike onto the trailer. Have been using a 2x10 piece of lumber with some funky bracket on the end with a block under the middle of it. Going to weld a plate on the tail end of the trailer so I can hook the ramp on it. Looking for suggestions on what to use. Car ramps are just built with honker angle iron. But they are short and am concerned with what will happen when the ramp is so long......