I've been riding my new (well not so new anymore) Corsa III's for a little over 400 miles now, and I have come to realize that these tires operate totally different from the Qualifiers I had on the bike previously (D207 in front). First lets get some details out of the way.

Bike: '07 ZZR 600 (ZX600J)
Rear Tire Size: 180/55
Front Tire Size: 120/65
Rear Tire Pressure (cold): 41.5 psi
Front Tire Pressure (cold): 36.5 psi
Suspension: Medium stiff (basically factory recommended settings)
Rider Weight (fully geared): 210 lbs
Mean Ambient Temp: 94 F

Both tires seem to get the job of cornering done, however they each go about it in different ways. First off the profile of the Qualifiers are slightly wider than those of the Corsa III's. Not by a whole lot, but definitely noticeable. I recognized this as soon as they were mounted on my bike, as now the rear tire was at least another 3+ millimeters away from the chain guard (I struggled to get clearance w/ the Qualifiers). The Corsa III's also have a much more acute profile (more triangular), whereas the Qualifier has a nice round shape to it. Looking at just the profiles of both tires, one could say that the Corsa III will effect a quicker turn-in, and that it might even put more rubber on the road once leaned over.

The Corsa III's do turn in noticeably quicker than the Qualifiers. Anyone who favors that fast flick into the corner will like these tires. Don't get me wrong you can flick the bike fast no matter what kind of tires you have on, however, the Corsa IIIs seem to really "notch-into" the lean once you initiate it.

Another thing that's very different between the two tires is the wear. Now with the front tire, the wear is almost the same. The side parts of the tire that mainly do the work in the corners have that distressed look and feel on both tires. On the Corsa III the wear is hard and tight (the little nooks and crannies are really close knit), while on the Qualifier the wear is hard but it's more the texture of the inside of a sweatshirt (fuzzy). The wear in the center of both front tires are the same - smooth.

In the rear, the Qualifier actually started off with that fuzzy look on the whole tire, but then, after a little over a 100 miles it was smooth all around. The same look that the tire has when it's brand new. The Corsa III, on-the-other-hand, is wearing similar to the front tire; with one exception. The rear tire has those hard packed distressed portions on the sides, but also the center is hard packed and distressed as well. What I'm saying is the whole tire gets those tight-knit nooks and crannies.

I'm not sure if this is a good or bad thing, it's just how they designed it. It just looks from the wear of the tire, that it's always sliding just a tiny bit around every corner, thereby "ripping" the rubber away to cause it to look this way. I say this because, if you skid the tires you get the same exact look (only deeper). Now it sure doesn’t feel like it's sliding, because it seems to do the job just as well as the Qualifiers.

Stickiness: I have no way of telling you if the Corsa III's are stickier than the Qualifiers. To do that would mean trying to do some really dangerous stuff. What I can tell you is that they seem to hold just as well (not better, or worse) than the Qualifiers.

I can also tell you, that riding on decent asphalt, going around a 21 foot radius corner at 55 mph at full lean (pegs scraping) that both tires felt very sure footed, exhibited no signs of slipping, and both gave great feedback (21 foot inner radius, usable lane width less than 9 feet). At what speed the tires would let go at - I have no idea. If the pegs are touching and the tires are still sticking, that's good enough for me.

In the rain, this is still undecided. The times I have ridden in the rain on the Corsa III's, it had just started, and the temperature came down drastically. No two rain days were very similar when riding either tire. So there is no telling which is really better in the rain. Just be careful when the road is wet on any tire.

The last thing I notice that's different between these 2 tires is that they heat up very differently. It's like night and day. The Qualifiers get hot very rapidly, and they stay hot for a lot longer. I say "get hot" instead of "heat up", because the two brands seem to have very different operating temperatures.

The Qualifier runs hot. This tire is on fire after about 5 miles of hard riding, and you will easily get an additional 2 psi in the tire once it starts rolling. The Corsa III on the other hand "warms up", but stays relatively cool compared to the Qualifiers. I wouldn't jump to the conclusion that since one tire is hotter than the other, that it will stick better. No, they seem to both work very well. Just at different temperatures, and with different rubber compounds.

Lastly, I don't know how many miles each tire will last for. Most of my riding is done on corners - accelerating included. So my tires tend to wear out on the sides far faster than the middle. I don't ride much expressway, and I tend to relax on the straights, so the middle of my tires don't get used as hard as the sides.

Which tire would I pick? Hmmn…, I really like the "new" look of the Qualifier over the distressed look of the Corsa III. Plus the way the Qualifier gets nice and hot gives me that warm fuzzy feeling inside. Although, the Corsa III's operating temp is so low that I can start hauling ass around the corners almost as soon as I get on without any worries.

Still undecided.