Width is what I meant, a 17x5.5 rim on a 180/55 is typical for 600/750’s, most 1000 and up are 6” wheels so the 180/55 would be stretched alil, usually those bikes come with a 190/50. Ppl go 190/55 to get a taller profile, 200/55 is even taller and alil wider on the same size wheel, but also a heavier tire. I’d think moto gp wants to pinch the tire to give it more contact patch when leaned over, that’s what I was wondering.