Originally Posted by
thumpism
Not true. Perimeter or backbone frame using the engine as a stressed member is at least as popular for the last forty years.
Example, '80s Yamaha Virago. There are plenty more.
True. Twin spar aluminum frames became popular in the 80s with sportbikes and they still are. But there are many other frame designs.
The Yamaha does looks nice. Sur Ron did something similar. I’m looking forward to ebikes with 80 mile range and around 200# to hit motorcycle trails with.