I don't yet have the bike, but will be buying one for use on track exclusively. My coach suggested Pirelli Diablo Supercorsa, but I'd like a stickier tyre. If the sizes were 110/140, I know what tyres I should get. But the rear tyre of Ninja 400 is larger, and my favourite tyre isn't available in this larger size. I'm not looking for stickiest tyres, but rather slicks that is stickier than the Diablo Supercorsa yet wear reasonable well on track.