Aluminum when welded "should" be much more rigid than steel all said and done. I'm having it way overbuilt also. The tounge is going to run the lenght of the trailer, (like on the larger trailex), it will be .25" wall, 2"x4". The rest will be same dimension just .125" wall. I've got so much bracing planned into it it's silly. Plus the trailer alone will be just over 20' long. I'm hoping that will add some stability with a longer wheelbase. My experince with other trailers, car, skidloader, enclosed etc. tells me I should have a torsion axle. Plus I have some cut-offs from comp tip refits for the mast crutch. How cool is that? I know its probably stupid to spend that kind of money on a cat trailer but I'm single, no kids, do fairly well financially, so why not. Fool and his money......what?