by QueticoBill » Tue Feb 07, 2017 9:29 am
IIRC the fatigue failure was in the tongue, and that does seem to be a point of higher stress.
I chose the NT 5*8 and plan to lengthen tongue along with moving axle back - both of which add to loads on tongue. The chart in design resources here says I'd be good with 2*2*1/8 but I'll use 3/16 or 1/4.
Otherwise, I don't sense an epidemic of frame failures based on reports here using either HF or NT. I believe they are more than strong enough for most teardrops. You're always better off keeping it lighter, something I keep evolving in my plans (though still too cowardly to go all foam!)
I make a living in design and construction and I know the sentiment of stronger is better but really, it only needs to be strong enough, and much stronger than that wastes resources and money.