Adding a Hitch To The Trailer

I built a lift for the back of my fiver for a 700 lb bike. I haven't welded it to the trailer yet. I am a little concerned about the weight that will be removed from my pin even though I will still have about 1800 lbs of pin weight after loading the bike. I am prepared to either add a third axle or move my existing axles closer to the back of the trailer if need be. My trailer has frame rails that are 18" deep and I used considerable caution in designing a hitch that can transfer the weight of my bike into the trailer frame rails without tearing away from the frame. The frame is deep but it is constructed of a lighter wall thickness than what would be ideal. I will be bolting and welding my hitch to the trailer. I am using two 2x4 inch hitch receivers and adding two cross members in order to transfer the stresses into the frame rails. The weight of the hitch and carrier is over 400 lbs.

With out seeing your set up I am not going to say much but my gut feeling is that your best solution is to buy a truck with an 8 foot bed and carry your bikes on the truck.