A 600 that remembered what mid-range is

600cc inline-four supersports are supposed to be useless below 8,000 rpm. That is the whole deal with the segment. You buy one for the looks and the noise and the track day, you put up with the lifeless bottom-end on the way to the canyon, and you call it character. The 2025 ZX6R KRT did not get that memo. This thing has actual mid-range power, on an inline four, in 2025, and I'm still kind of shocked about it.

I hadn't ridden a ZX6R in 11 years. Eleven. I expected exactly what a 636 is supposed to be. A screamer that doesn't move until the tach is past halfway. I rolled on at 4,000 rpm and the bike just went. "This bike gets up and going a lot faster than I kind of expected it to." That's not a sentence anybody writes about a 600 supersport.

Here's the thesis. The ZX6R is the most livable 600 inline four on sale, and the only thing keeping it out of the upper Chase Score tier is a set of switchgear that belongs on a Ninja 400.

Performance highlights

The 636cc inline four makes 122 hp and 51 lb-ft, which is the standard 600 supersport menu. The way Kawasaki tuned the delivery is what's different. Mid-range hits earlier than it should, traction control was kicking in in rain mode at low rpm, and that's just not how an inline four normally behaves. The throttle response earns its mark by being shockingly mature for a class that usually rewards the redline and punishes everything below it.

The 40–80 roll-on, in first gear, on wet roads, came in at 2.48 seconds. The actual run hit 90 mph by accident. "I tried to do a 40 to 80 pull, and I hit 90, so I feel like that's all I need to say." Every quick-shifted gear lifted the front. On a wet road. In first.

The Showa suspension is the other star. Even on damp asphalt I could lean the bike into a corner and just trust it. "That suspension feels locked. It got the bike leaned over a little bit. Bike was super compliant and just stayed exactly where I wanted it to stay." Brakes are Nissens, not Brembos, and on the street they're plenty. Strong initial bite, no drama. I'd take this same setup to a track day without changing a thing. The up-only quick shifter is, in Chase's words, "literally coated in butter."

Agility on a 600 is supposed to be effortless and this one is. 432 lb feels exactly the way you'd expect. Neither feathery nor heavy, just neutral and predictable through transitions.

Rider experience and tech

At 5'10" with a 32-inch inseam, the body position on the ZX6R is genuinely the most comfortable I've been in on a Japanese 600. Lower half is supersport-tucked, no surprise there. Upper half is less leaned over than the R6 or the Gixxer 600, which is why it shows up to the comfort sub-score with a six and not a four. Long stints don't break you in half. Short rider? You can flat-foot this one without effort.

The tech story is split. The dash is fine: bright, readable, all the info you need. The quick-shifter-up is excellent. There's no down-shifter and no launch control, which on a 600 in 2025 is a knock. But the real ease-of-use crime is the mode-change interface. "Kawasaki, listen, I am begging you. The mode switching has got to change. It takes far too long." Press and hold to go up a mode. Press and hold to go down. Off-throttle only. On a sport bike where mode changes actually matter: wet road, fast canyon, parking lot. You should not have to perform a 5-second ritual to get out of sport.

That ergonomic and switchgear story is also where the value sub-score takes its hit. $12,500 buys an excellent motor and a frustrating set of buttons.

The Chase Score & final thoughts

With a Chase Score of 69/100, Good Tier, the 2025 ZX6R KRT is the Japanese 600 that finally feels like it was tuned for the road as well as the track. 42 ride points + 27 usability points = a bike that earns the most-livable-supersport award and then immediately gives a chunk of it back at the switchgear. Here's the thing: the score would be in the 75+ Great Tier if Kawasaki put a real mode button on this thing.

Buy it if you want a 600cc supersport that you can actually ride to the canyon without hating yourself, and you're going to do track days. Skip it if you're new to riding (it's too much bike), if you live in stop-and-go traffic, or if you can't tolerate switchgear that feels a generation behind the engine bolted to it.