Been tracking what owners are doing here and on other social media platforms and haven't seen anyone change tires, we might be in for a bit of a wait. Too bad there aren't any motorcycle tire configurators just as there are car tire configurators.
Someone should really look into making something like that. But I can agree I haven't seen anyone that has done it yet. I would also like to look into that as well as I'm starting to think I would want a bigger tire on the back too. Nice beefy look.
I believe there is a good chance you could fit a 170 section back there but 180 might be a squeeze. If anything, I personally think you wouldn't benefit much from performance other than added weight. Have you considered a higher performance tire?
'17 Kawasaki Z650 ABS Stardust White
Long time car enthusiast, now a motorcycle enthusiast
Check out the manufacturer's websites for dimensions of the tires you are looking at. Then you can compare actual widths as they do vary between makers. Also, check the profiles as overall diameters will be affected by that width/profile calculation.