The Mini R6

Nobody builds a 400cc inline-four anymore. Except Kawasaki. The ZX-4RR is a 399cc four-cylinder super sport that revs to 16,000 rpm, makes 56 hp, weighs 414 lb, and sounds exactly like a Moto2 bike. It has no sensible mission in the American motorcycle market. Which is why Kawasaki built it, because they could.

Chase's on-camera reaction: "This might be the coolest 400 that exists on the market. You get all of the experience of an absolute lunatic inline-four cylinder in a 400 platform." This is the R6 experience, shrunk down, made a little slower, but keeping 100% of the character. For the right buyer, that's a genuine hook.

Performance highlights

399cc inline-four, 56 horsepower, 27 lb-ft of torque, 414 lb wet, 16,000 rpm redline, 31.5" seat. Throttle response scores 6. And the deduction is specifically a weird power-cut at high rpm that Chase felt mid-corner. "When you're really high revving this motorcycle, there's a weird on-off that the throttle does." Everything else is great; that one quirk dragged the rating down.

Acceleration earns 6. 40-80 in second gear alone. Chase only needed to upshift once. A 400 that hits 80 in second is the whole pitch.

Agility is 8. The class-high for any super sport on the leaderboard. 414 lb plus race-geometry makes the ZX-4RR razor-sharp.

Brakes rate 7. Nissin calipers with strong bite and good feel.

Suspension is 6. Fully adjustable Showa front and rear. Premium hardware at the price. Race-tuned firmness.

Rider experience & tech

Comfort is the expected 4. Super-sport ergos: clip-ons, race pegs, firm seat. But less crunched-up than expected because Kawasaki opted for a slightly more upright body position than the typical supersport.

Tech scores 4. Three ride modes, quickshifter, adjustable suspension, decent LCD dash. Held back by the persistent Kawasaki menu UX issue Chase has rated down on every Kawasaki review.

Ease of use is 4. Menu frustration plus required high-rpm riding style makes this a committed rider's bike.

Versatility is 4. City: surprisingly fun because you can rev high without going fast. Track: S-tier. Canyon: excellent. Highway: capped by ergos after ~2 hours. Fun-for-the-money is 4 at $9,699. The xlsx tally runs conservative.

The Chase Score & final thoughts

With a Chase Score of 53/100, Meh Tier, the ZX-4RR is a polarizing specialist. 33 ride points + 20 usability points = a bike where the ride experience is clearly Good-Tier-plus and the daily-usability sinks the overall score.

Buy it if you want the only new 400cc inline-four on sale, if you track-day seriously, or if you're a smaller/lighter rider who wants super-sport ergonomics without liter-class commitment. Skip it if you want a usable daily, if Kawasaki's UX frustrations matter to you, or if the high-rpm power-cut quirk worries you. Chase's close: "It's not perfect by any means, but holy Christ is it fun." Exact read.