honny the snaped 500af was a home made one in england the welds didnt penetrate deep enough on the gusset where the put the replacment cradle in the frame the below photo was taken before the snap if you look in the circle you can see where the frame is sperating
I doubt any frame would just suddenly break in two, this bike would have been handling a bit “funny” before it let go completely.
My 2000 model KTM 300 had its swingarm break clean through just in front of the axle where the webbing is still thin.
I pulled over 3 times to check to see if I had a flat because it was behaving weird.
Thinking it must be me I parked it and as I got off I noticed something shiny on the swingarm. Close inspection revealed it was broken clean through.
It was lucky I didn’t do any jumps with it like this as I doubt the other side would have held up by itself. With the chain being the only thing holding the rear wheel on I doubt the result would have been pretty.
