I’ll start with what the Ninja 250 FAQ guys said about the stock tires:
Sizes: 130/80-16 rear; 100/80-16 front
Loudboys: I don’t know what kind of situation the OE tires are designed for, but it sure isn’t regular street riding. They don’t handle predictably, they don’t stick very well, and they don’t last very long. The stock tires are fairly unforgiving compared to most of the good replacement options. Once they’re unstuck they tend to stay that way.
Ian: Dunlop K630’s are pieces of crap, and you’re doing yourself a huge dis-service by riding on them. “
Once I had the Sport Daemons mounted at the bike shop, it inevitably rained while I was waiting in the showroom. Even with new slick tires and rain-covered roads, I still felt like I had more traction than those Dunlaps had dry.