Interesting that you bring this up about the Pirelli catalog. When I asked the local Pirelli rep if he could get that 150 he said no. So I asked what tire he recommended....he said put a 140/70 supercorsa on there. Seems odd that a ninja400 comes stock with a 150, but the kids running motoamerica junior cup are running a 140. The rep says the 140 is lighter and has slightly larger diameter than a 150. I'm tempted to try a 140, but I am not planning on any track days for a while on NSR.

Interested to see how this thread develops. Currently my bike has a Q3+ 150 rear on it which was fantastic last year at COTA.