I have had Goodyear Eagle F1A2 on the back, they gripped in all conditions. Make an awesome front tyre, great handling and pull up fast for emergency braking. I currently have Michelin PSS 275-30-19 on the back. They take along time to warm up, but on a hot day with ambient temp above 30C and hot bitumen they will grip all the way through second at 450rwkw. However, on a less than 20C day no matter how long I warm them up they just dont grip that well. Will try the r888 next, but looks like I should move to an 18inch rim for ultimate street grip.