As far as I know, there’s no sizing in motorcycles. It’s one size fits all. That’s just stupid. Riding a moto is a totally ergo activity. Heck, even desk chairs are more ergo than motos!
The only moto I know that declares itself to consider sizing is the new Dan Hurley line of Alligators. They’re for big guys. So he’s not really sizing per se, just fitting himself. He’s tall.
I noticed this moto thing when I had a supercool old Yamaha 650 Special (ultra modified in the best ways—bought it 3rd-hand, didn’t appreciate what I had!). But it was SMALL!
I suppose some bikes are known to have small frames and some are made smallish on purpose. But, really, why not offer the same moto in 3 frame sizes?
A moto already has weird ergo—like an upright bike. You’re mostly prepped and ready for a head-launch.
(Ya know, people think the prone or belly recumbent bike is the weirdest bike of all—you pedal laying on your belly, stretched out, head first. But really, motos and upright bikes are a lot like this. Your CoG is basically head-first. The crotch-rocket motos especially. And most deaths are head impacts, right?)
Why not size moto frames? They sure as heck sell enough of them! Bikes come in a jillion sized frames and they sell nuthin compared to motos in America.
Why not also make them more safety ergo? Let’s see more truly recumbent motos. The current crop of step-thru’s are still too upright. I doubt that anyone has shown they handle worse. Well, I suppose they’d need better suspension, but whatever. I think that wrecks would tend to go lots better for riders if they were lower and feetfirst. Gas mileage sure would. That is, low and layed back is also lots faster. Far better aero. Much more readily faired…oh yeah!
Oh well, I’m conflating concepts again. Let’s start with the SIZING issue…