I’m running them on 30 inch radius. Th smallest I would go is 20 but for best looks I’d try atleast 24 inch radius.
Mine has never derailed around a curve and I’ve put it upfront with 20+ cars behind it.
It comes with ez mate couplers and if you want to switch them to kd’s you have to file done the opening where the coupler comes out so the centering spring and the coupler fits.
I don’t know of any other companies that make them. There are bras ones but of course they are really expensive.
Andrew
I run my autoracks around 22" radius all the time and have never had a derailment but they look better on my 24" r. I also pu***hem around a 22"r and through Atlas #4 turnouts with out trouble. I did have some uncoupling problems due to uneven track but this was easy to fix by adjusting the track. They will find spots that you don’t even know were low. I did replace the couplers with KD’s because I do not like plastic couplers.
I run them on 36" radius which works fine, but they are monsters! I had to re-do a couple tunnel portals and liners, and some side-by-side track center spacing to get them to clear.