Adding big deck/ extra axle to a 5er. Carry 4 motorcycles.

I ran a pin weight calculation for loaded and unloaded and it stays within reasonable limits. The 3rd axle transfers a lot of weight to the pin. In fact, the pin might be on the heavy side without the bikes.

I'm going to add a 2nd fresh water tank to the trailer if I do this. I'll use it as ballast if the pin is too light with the bikes on.

The real solution to all this would be to have sliding axles like on some commercial trailers.

I got my axles from Southwest Wheel.