The Ninja bloodline makes up Kawasaki’s fiercest two-wheeled warriors, and when the battlefield is set at the racetrack, the Ninja ZX-10R leads the charge for the Japanese firm. With seven World Superbike Championship titles to its name, six of which with Kawasaki Racing Team pilot Jonathan Rea at the helm, the ZX-10R has proven itself time and time again.
The 2021 Kawasaki Ninja ZX-10R’s refinement this year goes well beyond its fresh new looks and more track-focused riding position. Indeed, the engineering fairy dust has resulted in a more agile chassis, refined suspension, and engine tweaks to satisfy Euro 5 emissions standards, as well as the needs of KRT and Mr. Rea.
We took to Auto Club Speedway in Fontana, Calif., where we could stretch the 2021 Kawasaki Ninja ZX-10R’s legs and check out these updates for ourselves. Enough jibber-jabber! Let’s get on with the Fast Facts.
1. Beauty is not just skin deep, friends. The Ninja still sports an appropriately sharp and chiseled look. At the same time, its new bodywork integrates aerodynamic winglets that produce 17 percent more downforce and seven percent less drag resistance—the latter improving comfort. Admittedly, downforce is tough to quantify without back-to-back testing. However, I did note that the refreshed Ninja seems less prone to wheelies while accelerating WOT. Meanwhile, the benefits of a taller and steeper angled windscreen are readily apparent, providing plenty of protection while ripping down the 170+ mph front straight. Lastly, new side panels help disperse engine heat away from the rider.
2. A racier riding position works in harmony with the new styling. Capitalizing on the aero advancements, the updated rider triangle puts more weight over the nose. To that end, the clip-ons are nudged almost a half-inch forward and are much flatter, giving the cockpit a more open feel while also allowing more leverage. That’s where the 32.9-inch seat comes in with its elevated rear section, helping me get into a proper full tuck behind the windscreen. The redesigned footpegs are more comfortable and are 0.2 inches higher, creating more ground clearance while keeping you in a more athletic position. Not only that, the rear brake reservoir is relocated to create free-up movement—per Sir Jonathan’s orders.
3. Designers are keeping things tidy on the 2021 Kawasaki Ninja ZX-10R. Mitsubishi LED lighting is now standard fare aboard the Ninja, along with the iconic Kawasaki River Mark emblem. Turn signals are integrated into the mirrors, which can be easily popped off for track riding.
4. The 998cc in-line four-cylinder engine is still quite the howler. Packed with high-revving fixings like a lightweight DLC coated finger-follower valvetrain, short pistons, titanium exhaust valves, and a low-inertia crank, the ZX-10R is all business when you bring the revs up to about 8000 rpm. Bottom-end torque is stereotypically soft for this inline-four. That all changes with that whiff of midrange, which quickly ushers the rev counter towards the top end and peak power at 11,500 rpm. It’s all screaming overrev until the 14,200 rpm redline and silky smooth throughout.
5. Shorter gearing makes all the difference. The previous ZX-10R had long gearing that often didn’t mesh with tight, technical sections of a racetrack or the street. Kawasaki engineers shortened internal gearbox ratios in 1st, 2nd, and 3rd gears and the final-drive gearing, bumping up a couple of teeth to a 41T rear sprocket. The result is a ZX-10R with a little more potency in the point-and-shoot infield sections of Auto Club Speedway, and it should help on the road.
6. A six-speed gearbox, slipper clutch, and up/down quickshifter are standard on the new ZX-10R. Once I left pit lane, the clutch lever was almost unnecessary, thanks to the slick quickshifter. Shifting is precise as it has always been, in both directions, unless you spike the rpm a bit too high and need to wait for the revs to settle before going down a gear. Helping you keep things in shape is the slipper clutch, which comes in handy on the track.
7. A new exhaust system and oil cooler are part of the Euro 5 process. Catalyzers in the titanium headers scooted upstream for quicker warmup times, and the collector has a new layout, all while keeping the same power output. Coupled with that is the new oil cooler with an independent circuit that helps regulated oil temperature, thus allowing more performance for the KRT lads and tighter emissions tuning for the common folk.
8. Speaking of power figures, I suppose it’s a good time to talk about superbikes in the North American market. We should note that American subsidiaries of Japanese motorcycle manufacturers rarely cite peak horsepower and torque figures. However, Kawasaki representatives did make it clear that power is capped at 11,500 rpm due to EPA noise emissions regulations, hence why our ZX-10Rs—and nearly all superbikes in the U.S.— flatten out around then. Don’t worry; the engine is still a beast in stock trim. Luckily, Kawasaki has over 70 go-fast parts for racers, including a Race ECU, racing wiring harness, conrods, cranks, and much more.
9. A full suite of electronics helps tame the 2021 Kawasaki Ninja ZX-10R. A five-axis Bosch IMU (the sixth axis is calculated) informs five-level traction control, cornering ABS, wheelie control, an engine braking mode, engine power modes (Full, Mid, and Low), cruise control, launch control, a quickshifter, and an Öhlins electronic steering damper. Instead of offering the typical litany of adjustments, Kawasaki takes a more holistic approach to its rider aids. Your chosen ride mode (Sport, Road, Rain, Rider 1-4), as well as the traction control setting, dictates intervention levels. It’s a more simplistic approach. However, ABS and wheelie control are tied to TC, so you can’t adjust them independently.
10. I hear you; I hear you! Let’s talk about how the electronics work. New for this year is a proper ride-by-wire throttle that uses friction to simulate the feel of the now non-existent throttle cables. I stuck with the Sport throttle map, which offers the most athletic power delivery—perfect for the track. The only hiccup is the abrupt response during initial input—on or off—it takes an extremely tempered wrist to overcome. Your TC setting is a one-stop shop for ABS, TC, and WC. Level 1 is definitely for the brave, allowing an eye-opening amount of wheelspin and sliding that puts the onus on the rider—with freedom comes great responsibility, kids. For my abilities, TC 2 provides a good safety net without hampering drive.
11. Brembo kit brings the fire power. Unchanged from previous years, the Brembo M50 calipers and massive 330mm rotors return, along with a Brembo radial master cylinder. Power is as immense, as you’d expect from the mighty M50s. While feel is good, it could be better with steel braided lines over the ZX-10R’s rubber hoses. The rear brake has more aggressive pads and is still great for tightening up lines.
12. I’ll be taking a mulligan on the ABS. Usually, I would have an observation ABS intervention. Due to Euro 5 standards, ABS cannot be disabled, and Kawasaki doesn’t offer a less restrictive “track” ABS setting like many of its competitors. Instead, a convenient fuse was pulled (located directly under the seat), which disabled $1000 ABS completely, yet retained its additional 4.4 pounds. In sunny Southern California conditions and running awesome slicks on the bikes, we were deemed competent enough not to chuck the bikes down the road. No one did, and there was much rejoicing. Of course, this is an essential safety for road riding, so do not disable it for street use.
13. Finally, a full-color 4.3-inch TFT display is here. Fiddling with all those settings is done from Kawasaki’s trusty full-color dash that’s seen on heaps of its models. It’s simple, straightforward, and easy to read. As usual, it features Bluetooth connectivity, and with Kawasaki’s Rideology app installed on your mobile device, you can review riding logs with speed, rpm, gear position, and more. Additionally, navigation and service reminders are available. It isn’t the flashiest in class, but it’s far better than the Casio watch-inspired dash of yore.
14. The ZX-10R’s chassis is its standout trait. I lauded the ZX-10R’s aluminum twin-spar chassis for its stability, mechanical grip, and feedback in our 2019 long-term test. However, the Kawasaki has always been a physical bike that enjoyed rider input. Livening up the bike’s handling is a 2mm fork offset that shortens the trail figures. To retain the Kawi’s stability, the rear wheel scooted back 0.4 inches to increase the wheelbase, and the swingarm pivot point is 1mm lower. Those changes help shift the weight bias a marginal 0.2 percent towards the nose, creating a more agile motorcycle without sacrificing control.
15. Fully adjustable Showa suspension receives updates. Front-end feel is another high point, and the updates are about sweetening those sensations. Although a wider lower triple clamp is claimed to add rigidity into the mix, I noticed the spring and valving changes. The fork now uses a slightly lighter spring with heavier compression damping and softer rebound damping. This helps you pitch the bike in on the brakes and stay composed. In the rear, the spring rate is up, while the damping is softened overall. There’s more support during corner exits without becoming harsh, egging you to get on the pipe.
16. Hey! You were on slicks; doesn’t that always make a bike handle better? Speaking generally, the taller rear profiles of racing slicks will raise the bike’s back end and often encourage faster steering. We had the luxury of Bridgestone Racing Battlax V02 (120/60 front; 200/65 rear) racing slicks that have more grip than I know what to do with. They’re excellent, delivering great feel, grip, and break traction predictably should you be so bold with the gas. In stock trim, expect more than capable street-legal Bridgestone Battlax Racing Street RS11 (120/70 front; 190/55 rear). I used several different slicks on our 2019 long-term bike and have a reference point—it handles a little better on the track.
17. In 2021, the Kawasaki Ninja ZX-10R is only getting stronger. The Ninja ZX-10R has made its bones at the racetrack, whether you’re talking about track day heroes, club racing, MotoAmerica, or World Superbike titles for a good reason. It has a stomping top-end loving engine with an excellent chassis to match, and a competitive electronics package. The 2021 Kawasaki Ninja ZX-10R improves on those strengths, making it more comfortable and stable with aerodynamics while also adding some agility into the mix, thanks to chassis and ergonomic updates. There are a few Euro 5 teething issues with the new throttle, but its bones are sturdier than ever, and it’s still one of the best values in the class.
- Helmet: Arai Corsair-X
- Suit: Alpinestars Racing Absolute
- Airbag: Alpinestars Tech-Air
- Baselayers: VnM Sport Compression
- Gloves: Alpinestars GP Pro R3
- Boots: Alpinestars Limited Edition Victory Supertech R
2021 Kawasaki Ninja ZX-10R ABS Specs
- Type: DOHC inline-4
- Displacement: 998 cc
- Bore x stroke: 76.0 x 55.0 mm
- Compression Ratio 13.0:1
- Maximum torque: 84 ft/lbs @ 11,300 rpm
- Fueling: Four Mikuni 47mm throttle bodies
- Transmission: 6-speed w/ quickshifter
- Final drive: Sealed chain
- Front suspension; travel: Fully adjustable 43mm inverted Showa Balance Free Fork; 4.7 inches
- Rear suspension; travel: Linkage-assisted fully adjustable Showa BFRC-Lite (Balance Free Rear Cushion) shock; 4.5 inches
- Tires: Bridgestone Battlax Racing Street RS11 (Bridgestone Battlax V02, as tested)
- Front tire: 120/70 x 17 (120/60 x 17, as tested)
- Rear tire: 190/55 x 17 (200/65 x 17, as tested)
- Front brake: Semi-floating 330mm discs w/ Brembo M50 4-piston calipers
- Rear brake: 220mm disc
- ABS: Cornering ABS standard
DIMENSIONS and CAPACITIES
- Wheelbase: 57.1 inches
- Rake: 25.0 degrees
- Trail: 4.1 inches
- Seat height: 32.9 inches
- Fuel tank capacity: 4.5 gallons
- Curb weight: 456 pounds
- Colors: Metallic Spark Black/Metallic Matte Carbon Gray; Lime Green/Ebony/Pearl Blizzard White (KRT Edition)
- 2021 Kawasaki Ninja ZX-10R Price: $16,399 MSRP
- 2021 Kawasaki Ninja ZX-10R KRT Edition: $16,999
- 2021 Kawasaki Ninja ZX-10R ABS Price: $17,399 (tested w/ ABS disabled)
- 2021 Kawasaki Ninja ZX-10R ABS KRT Edition: $17,999
2021 Kawasaki Ninja ZX-10R Review Photo Gallery