If I had it to do over again with the Flexiride I would make sure that I bought the accompanying brackets for bolt on. If I remember correctly there are mating brackets you can weld to the frame and then bolt the axle to them.
Not that you are likely to need to replace the axle.
Also measure YOUR frame to get the inside and outside dimensions since my frame was not the specified width.
That meant that the brackets on my axle did not hit perfectly making putting a plate over the connection was not in the cards.
The dealer will make the axle special at no extra charge as they make it for you.
In my case I felt that 3500 was too heavy of a spring rate and 2500 was too
light. They happily made a 3000 on the frame of the 3500 by changing the rubber in the square section.
I assumed that the specifications from (in my case the AL-KO) would fit perfectly.
The axles on the new trailers are probably installed on the bare frame where welding at the junction of the bottom of the frame to the bracket is easily made, but with the shell mounted the accompanying mounting brackets make welding easier since the axle is not in the way.
http://www.theuniversalgroup.com/w/w...nt-hangers.pdf