[ZX-12R]

Besides the bike, your own preference will come into play as well. My 12R has a 6" rim and came from the factory with a 200. I've tried both a 180 and a 190 on it and have come to like the 190 the best. With a 180, it felt like the bike was falling into corners where the 190 rolls in smoothly and gives me better feedback from the road.

Dropping to a 190 made it feel like the bike lost 60lbs!