I'd disagree about the notion of there being no such thing as a frameless motorcycle. At the very least the BMW Telelever boxer bikes use the engine as the "frame". There are subframes attached to the front and rear to hang things on but that's all.
Frameless design is pretty much a certainty and I'd say even a necessity for EV motorcycles to ultimately compete with ICE to get the pack large enough and light enough.
Cas
That's just it, and I explicitly said so -- that's not frameless. On those boxers, the engine also serves as the central part of the frame, and the front & rear subframes that attach to it are also part of the frame. And of course there are other designs like this. "frameless" does not mean "lacking a separate load-bearing-only frame".
Anything which is required to bear external loads is by
definition part of the frame, no matter what other purpose(s) it serves. Which is why there can't be frameless motorcycles, at least not in non-zero gravity