Did ya check your suspension and tire pressure? I'd do that before forkin' out the green for a new tire... they're both free! Also, general rule of thumb as I have been taught is to keep your tires standard from front to rear... Mixing and matching two different tires, with different grip and other characteristics is probably not a good idea... Bottom line, front and rear are designed to work together and unless you really know what you are doing, you probably shouldn't fuck with that. I'd also go with the stock 190... The engineers put it on there in the first place for a reason, why fuck with it? Plus, you need to consider what the change in tire width is going to do to your tire height as well. A 200 tire is not going to fit on your rim the same way so the 50 sized 200 will actually have a higher overall profile from being pinched, despite both the 190 and the 200 being 50's... In other words, it'll increase the tire's diameter in relation to stock. Now the difference may be negligable in this instance, but in others it may not. It's surely worth considering though. That being said, if you do buy new tires, I give props to the Diablo's. I have them on my bike and they are pretty nice. I will say this though, they do square off REALLY quickly, but I have not noticed any problems in the twisties. I have over 3k on mine, 1k or so were really hard miles... I am guessing another 2k out of them...