What is the better rear tire size for a 2006 Kawasaki ZX10R?

Question

What is better for steering and handling? A 190/55/17 or a 190/55/17?

Answer 1

You put the same two tires down, I guess you meant the 50 series as the other option. The taller tire usually makes a stock ride height motorcycle turn in quicker and hold the line. The manufacturers make the bikes a little too stable so they don't get sued for tank slapping bikes in the hands of morons. So most sportbikes handle much better raised up slightly in the rear. Either way you can adjust the ride height to make the bike handle how you like. Also the taller tire gives more when leaned over providing better traction at the limits.