Extending and adding an axle questions

[Joe Bob]

I have a 16 foot single axle pop-up. I have raised the frame 9 inches, went with 15 inch wheels and plan on extending the frame another 7-8 feet ala the Baja format. The purpose is to transport ATVs and bikes.

The easiest way to extend the frame is to the rear for loading, weight distirbution etc..... As such adding another axle would be a good idea.

I can pick up a 3500 lb torsion model for a good price, heavier than the existing one. Without significant mods which I am unwilling to do, I will have about a 6 foot gap between axles for tire clearance with the pop up frame.

Is this a bad thing? All the tandem and triple axle trailers I have seen have minimal separation between the axles.

Yes, I can go out and buy a double axle Baja....but I like to tinker. I am an experienced welder.....I just need to know the issues involved with space between the axles.