It’s a uncommon state of affairs when a motorbike debuts in a category of its personal, however that’s what we now have right here within the 2023 Kawasaki Ninja ZX-4RR. Certain, the Ninja 400 has been a well-liked member of Workforce Inexperienced for a number of years and is a superb streetbike, however its parallel-Twin engine is way extra pedestrian than the shrieking 4-cylinder motor on this little screamer that revs to 16,000 rpm. 

Additionally vital is how upscale this factor seems to be. It seems way more unique than most different smaller-displacement sportbikes, resplendent in its Kawasaki Racing Workforce (KRT) colour and graphics.

Including to its upmarket presentation is TFT instrumentation, full LED lighting, an up/down quickshifter, traction management, and dual-disc entrance brakes with radial-mount monoblock calipers and normal ABS.  

Commercial

The ZX-4RR has the potential to reinvigorate the sportbike market, offering a gateway to high-level efficiency in a bundle that’s each tamable and attainable. Its energy naturally pales compared to a fire-breathing ZX-10R or perhaps a ZX-6R, however the 124 mph proven on its speedometer on the finish of Thunderhill Raceway’s entrance straight demonstrates its potential for velocity.  

Associated: 2024 Kawasaki Ninja ZX-6R | First Look Review

Class Revamp 

The 400cc sportbike market raged within the Nineties, with high-end race replicas from each Japanese OEM obtainable of their home markets. American importers had been skeptical that these dear little bikes would discover a lot enchantment to riders on our shores, however Yamaha took an opportunity and provided its FZR400, which earned a fame as one of many best-handling bikes of its period.  

Manufacturing of the FZR400 started in 1987, and the bike was recurrently up to date till its demise in 1994. The Yamaha’s inline 4-cylinder used a 56.0 × 40.5mm bore and stroke stated to supply 59 hp at 12,000 rpm, with an over-rev functionality as much as its 14K redline. Racy steering geometry ensured agility, aided by an aluminum body that saved moist weight all the way down to about 410 lb. 

Sadly, I missed out on my likelihood to trip any of the 400s from that golden period, so I used to be stoked for the chance to check a recent model of this forgotten class.  

A New Period 

The Kawasaki Ninja ZX-4RR was primarily developed for Asian markets which have licensing and insurance coverage rules to encourage the usage of smaller-displacement bikes. Simply as Yamaha took an opportunity within the U.S. market with the lovable FZR400, Kawasaki is doing the identical with this newest Ninja.  

A typical perspective about small-displacement sportbikes in bigger-is-better America has been that we’re not a lot all in favour of them, however the U.S. market is evolving. Kawasaki tells us that uptake on the 4RR has been sturdy on the seller stage because of the bike’s distinctive promoting proposition.  

A part of the Kawi’s distinctiveness is its capacity to rev as much as a stratospheric 16,000-rpm redline, which is larger than any engine provided within the USA other than the Ducati Panigale V4R’s 16,500-rpm rev ceiling. The 4RR makes use of a extra oversquare bore and stroke (57.0 x 39.1mm) than the FZR400 to securely obtain these lofty revs, together with solid camshafts and triple-rate valve springs.  

Kawi’s USA arm doesn’t present horsepower figures, however its Euro importer touts 76 crankshaft hp at 14,500 rpm. Torque peaks all the best way up at 13,000 rpm with 28.8 lb-ft.  

Associated: 2020 Kawasaki Ninja 650 | Road Test Review

EPA Killjoy 

Sadly, EPA noise rules imply that the 4RRs coming to North America are restricted, almost certainly by the use of the digital throttle valves at excessive revs. Our 4RRs produce peak energy round 11,500 rpm in keeping with a dyno chart equipped by Graves Motorsports, simply shy of 60 hp on the rear wheel. Upconverting that quantity to a rated-at-crankshaft determine interprets to about 65 hp, a minimum of 10 ponies down from its Euro spec.  

The 4RR proved to be thrilling to trip, however I’d really feel a bit of gypped to personal one and never have entry to the bike’s full potential. Bikes like these are ceaselessly fitted with aftermarket exhaust programs that drastically enhance the sound from the tailpipe, so the EPA’s intentions will seemingly have restricted real-world influence.  

If I owned one, the very first thing I’d do is go to Graves Motorsports for an ECU reflash, although that will be unlawful within the eyes of the EPA. For trackday/racing use solely, a reflash and a cat-back slip-on muffler from Graves leads to a claimed 76 rear-wheel hp, an enormous 37% enhance. Yee-haw!  

Racetrack Prepared 

Kawasaki may’ve cheaped out and hosted the 4RR’s launch with a avenue trip however fortunately made a bolder transfer and rented Thunderhill Raceway for us to divine the bike’s most efficiency potential. And we’re glad it did – flogging the latest Ninja on the entertaining and hilly racetrack in Northern California elicited numerous grins and nil moments of panic.  

The 4RR feels mild and manageable upon first straddle of its 31.5-inch seat. It scales in at 415 lb with its 4-gallon tank full, which equates to about 390 lb of car weight, regardless of a metal (quite than aluminum) body. Ergonomics are sportier than the Ninja 400 however much less punishing than Kawi’s ZX-6R or ZX-10R. The seat has a shocking quantity of fore/aft room to accommodate riders of assorted sizes and altering physique positions on the monitor. 

The hassle required to make use of the bike’s slip/help clutch feels impossibly mild, and each hand levers are adjustable over 5 positions to swimsuit arms of any measurement. The 4.3-inch TFT encompasses a Circuit Mode for lap timing and to show track-related data in an easier-to-view format. Kawasaki’s Rideology app can join the bike to smartphones.  

The Kawasaki Ninja ZX-4RR consists of two energy modes – with a Low setting for less-experienced riders– and three trip modes (Sport, Highway, and Rain) with preset Kawasaki TRaction Management (KTRC) and energy modes. Additionally obtainable is a Rider mode through which the programs could be set independently, together with three ranges of traction management with the flexibility to be switched off.  

For my first session, I used Sport mode and saved the traction management at its least-intrusive setting. The 4RR doesn’t have an IMU to tell TC or braking, relying as an alternative on wheel-speed differentials, so there’s no lean-sensitive TC or cornering ABS.  

GEAR UP

It had been years since I had ridden Thunderhill, and the rider-friendly nature of the Ninja was a perfect confederate to relearn the monitor. Pointing the bike at apexes required solely modest effort. Gear modifications had been clicked off effortlessly because of clutchless upshifts and downshifts provided by the quickshifter, an simply seen gear-position indicator, and a tachometer that exhibits revs above 10,000 rpm on the high of the show. 

After only some laps, I used to be dragging knees in corners and reducing seconds off my early lap occasions, smiling in my helmet because the Ninja complied with my inputs. The little 4-cylinder engine screams with an exquisite wail because it sings to its redline, but it surely’s smarter to shift round 12,000 rpm when the ability ranges off as a result of cursed EPA restrictions. Consumption snorkels with differential lengths (40mm and 60mm) do their greatest to supply a broader unfold of energy, however you’ll wish to rev the snot out of the little Ninja for the optimum expertise.   

Associated: Kawasaki Announces More New and Updated 2023 Models

Star Energy 

Through the subsequent session, I discovered myself behind a rider I didn’t acknowledge from the motojournalist ranks. He was reducing some good strains, and it was enjoyable to catch him in some locations and lose time in others throughout our little cat-and-mouse recreation.  

On the finish of our 30-minutes session, I walked over within the pits to say howdy to this stranger and categorical the leisure I bought from dicing with him.  

“Oh, hello, I’m Dax,” he replied.  

Wait a minute…Dax? There can’t be many Daxs on the earth, so I lastly made the connection that I used to be ripping round with Dax Shepard: actor, podcaster, and husband of film star Kristen Bell! It was pleasant to see a celeb with the flexibility to tear round a racetrack.  

“Being broke in Michigan, what I’d’ve cherished was a Corvette ZR-1. I bought my Katana 600 for $1,800 used, and it was quicker than a ZR-1,” Shepard advised us about his love for velocity, which started with a humble Honda Spree.  

“I’ve at all times been blown away by how cheap it’s to have efficiency with a motorbike,” stated the co-host of High Gear America. “I had a few completely different monitor bikes, and apart from tires, I’d by no means executed one factor to them. So the notion that you may have a car that you may go to 20-plus trackdays and never be changing rotors and pads and suspension elements, it’s bang for the buck – probably the most enjoyable anybody may have.” 

Please, Sir, Can I Have One other? 

Not like a literbike, which could be exhausting to thrash round a racetrack, I remained raring to go even after full 30-minute classes. What’s refreshing is time – time to ease your grip on the bars, time to breathe, time to research.  

Though I didn’t really feel traction management intruding a lot throughout earlier classes, I did discover ABS kicking in at a few braking zones. I ended up disabling traction management and ABS so I may trip unencumbered by the digital nannies. Energy utility turned extra direct with a stronger pull out of corners, so TC certainly had been kicking in throughout earlier stints.  

I used to be initially fearful in regards to the grip from the inventory Dunlop Sportmax GPR300 tires, which appeared to be a substandard alternative for a trackday. Surprisingly, they caught fairly properly, all the best way as much as and previous footpeg-scuffing ranges.  

The suspension carried out fairly properly for my weight, though heavier riders had been making changes to the inverted Showa fork and absolutely adjustable Showa BFRC Lite shock that’s much like the one used on the ZX-10R. The 37mm fork makes use of SFF-BP internals, through which the large-diameter damping piston supplies extra floor space to work together with oil, which permits the fork to maneuver extra easily in the course of the preliminary a part of its stroke. Adjustable spring preload on a fork is a primary for this class, but it surely’s the one setting that may be altered.  

The radially mounted 4-piston monoblock calipers and 290mm discs are lots for bleeding velocity from the 399cc engine and provide a good quantity of suggestions. Switching off ABS provided an enormous enchancment in confidence on the racetrack. The quickshifter was an enormous profit as properly, with auto-blipping downshifts and the slipper clutch permitting hurried gear modifications. 

Who Needs One? 

Being in a category of 1, the 4-cylinder ZX-4RR stands aside from different small-displacement choices. Its $9,699 MSRP permits the bike to have high-end options, however some will level out that a way more highly effective ZX-6R prices solely $2,600 extra when outfitted with ABS.  

Or you may get the twin-cylinder Ninja 400 for as little as $5,699 with ABS, however then you definitely’d miss out on TFT devices, dual-disc entrance brakes, traction management, and adjustable suspension, plus you’d quit a bunch of energy and the siren track of a high-revving four-cylinder motor.  

It’s value reiterating how a lot of a gigglefest it’s to hammer a modestly powered however light-weight sportbike round a racetrack, even for riders with a long time of expertise on high-powered literbikes. And for individuals who could be taking to the monitor for the primary time, a sporting motorbike just like the ZX-4RR is a perfect software to learn to do it correctly.  Mr. Graves, please ship a reflashed ECU ASAP. 

2023 Kawasaki Ninja ZX-4RR Specs

• Base Worth: $9,699 
• Guarantee: 1 yr., unltd. miles  
• Web site: Kawasaki.com 
• Engine Sort: Liquid-cooled, transverse inline-4, DOHC w/ 4 valves per cyl.  
• Displacement: 399cc  
• Bore x Stroke: 57.0 x 39.1mm 
• Horsepower: N/A 
• Torque: N/A 
• Transmission: 6-speed, cable-actuated slip/help moist clutch, up/down quickshifter 
• Ultimate Drive: Chain  
• Wheelbase: 54.3 in.  
• Rake/Path: 23.5 levels/3.8 in. 
• Seat Peak: 31.5 in. 
• Moist Weight: 415 lb  
• Gas capability: 4.0 gal.

See all of Rider‘s Kawasaki coverage here.