2018 KTM RC 390 vs. Kawasaki Ninja 400 ABS Sport Bike Comparison

The lightweight sportbike class has reached a feverish pitch as of late. That’s good news as these smaller motorcycles are designed to be widely accessible functionally and financially.

Better yet, manufacturers are pushing the boundaries of what a lightweight bike is by constantly increasing engine displacement, chassis, and suspension performance.

In 2015, KTM introduced the game-changing KTM RC 390, which quickly staked its claim as the top of the heap for entry-level supersport motorcycles. Since then, the KTM has remained relatively uncontested in terms of outright performance within this class. The RC has also enjoyed modest updates in the interim.

This year, a new challenger has arrived—the 2018 Kawasaki Ninja 400. It’s not a pumped up Ninja 300. The 2018 Ninja 400 is an all-new motorcycle.

With nearly identical numbers across the spec sheet—save for the number of cylinders in the engines—these lightweight Supersport machines seem evenly matched when going toe-to-toe. Though they share plenty of stats on paper, their riding experience is distinctly unique and will cater to a certain type of rider, so let’s get on with the comparison.

The big news for this category and the new Kawasaki Ninja 400 is its large bump in displacement, with its peppy 399cc parallel-twin liquid-cooled engine. Although Kawasaki North America doesn’t claim dyno figures, its European counterparts do—informing us of claimed peaks of 44 horsepower at 10,000 rpm and 28 ft/lbs of torque at 8000 rpm. This hits the sweet-spot in terms of street performance—plenty of power for the canyons and commuting, while not being overwhelming.

The Kawi’s purring little parallel twin is smooth and incredibly accommodating. Novice riders will surely be pleased with the tractable power and flat torque curve, making this an easy motor get a grasp of while keeping things wildly fun.

Grab a fistful of the Ninja 400’s crisp throttle and you’ll hear an engaging bit of intake-howl. There is plenty of get-up-and-go to make passes on the freeways, as well as getting your canyon or track fix on the weekends.

In contrast, the KTM RC 390’s 373cc DOHC single embodies the Austrian brand’s Ready To Race slogan. The raucous and raw motor claims to pump out an eyebrow raising 44 horsepower at 9500 rpm and 26 ft/lbs of torque at 7250 rpm—those are impressive numbers for a street-legal single, and on par with Kawasaki’s DOHC twin. Given KTM’s long history with producing bleeding-edge dirt bikes, that shouldn’t come as a shock; the company knows a thing or two about getting the most out of thumpers and the KTM doesn’t act like one at all.

Twisting the ride-by-wire throttle will have you exploring the tractable power on tap with the KTM RC 390. It’s incredibly easy to control, and while it takes a little bit more finesse with the clutch from a stop than the Kawasaki, everything after that is progressive and predictable. Because it’s a thumper, the RC 390 is more prone to vibration at the bitter end of the rev-range than the Kawasaki’s parallel twin, and it casts off more ambient heat.

At higher sustained speeds, the Kawasaki’s twin-cylinder doesn’t work as hard as the KTM’s 26cc-smaller single. That translates to a smoother ride when traveling along the highway or freeway, and a much improved fuel economy over its rival. Over all, when stretching its legs, because the Kawasaki’s 399cc parallel twin has a higher rev ceiling, it feels like it has just a bit more at the top end.

Both machines are paired with good six-speed transmissions that are matched to slipper clutches—a nice safety feature for riders of all skill levels.

When riding at an average pace, these bikes barely sip fuel and the KTM’s 2.6-gallon fuel capacity seems completely adequate. However, when the pace picks up and you’re wringing the single out, you’ll be making plenty of trips to the gas station. The Ninja 400, with its 3.7-gallon tank, has substantially more range.

When the KTM RC 390 made its debut on the US market in 2015, it turned heads for many reasons—not just because of its brash looks, but because it came equipped with components such as the 43mm WP inverted fork, although that is non-adjustable, something that isn’t typical of this segment. Rounding out suspension duties is a WP shock featuring spring-preload adjustment and a linkage-free mounting to the swingarm.

The RC 390’s high-quality WP suspension is well sprung and firmly damped; however it focusses on compliance and works exceedingly well on the street. Although it does feel firmer than the Kawasaki’s, it soaks up all but the biggest bumps and holds its line through a corner well when you feel like tossing the 2018 KTM RC 390 into a choice set of twisties. There can be a bit of unsettling if you hit a sizable bump mid-corner, however the KTM’s excellent damping settles things down quickly and the RC 390 stays in good shape.

As far as track abilities go, the KTM RC 390 is a proven platform, given its time in the KTM RC Cup spec racing series.

The Kawasaki Ninja 400’s non-adjustable 41mm Showa fork and spring-preload adjustable KYB shock tell a similar story to the KTM. The suspension definitely feels softer sprung than the KTM, however the damping is so spot-on that the Kawasaki is exceptionally well-behaved, even if you’re wringing it out through the corners.

Whether you’re dealing with your commute, hitting the canyons or heading out for your first track outing, the Kawasaki’s traditional fork and linkage shock aims to please through a good balance of handling compliance and comfort. However, the KTM’s fork additional firmness helps it feel slightly more refined when moving through its stroke.

Thanks to the sporty wheelbases, 53.6 inches on the Ninja and an inch less on the RC, it requires almost no effort to toss either of these lightweight sport bikes on to the edge of the tire. Although this makes them the perfect platform for new riders, more experienced riders with some skill will be able to extract all they can out of them, without ever getting bored.

There is a great deal of feedback through either chassis and I’ve been perfectly happy in either case. Both motorcycles are very stable, while the Ninja 400’s longer wheelbase and additional rake makes it slightly more surefooted.

With both motorcycles running within a pound or two of 365 pounds gassed up—keep in mind the Kawasaki carries an extra gallon of fuel with the tank full—they are nearly evenly matched in terms of side-to-side transitioning. The KTM with its inch-shorter wheelbase and nearly one-degree steeper rake edges out ahead in that regard, and the shorter wheelbase and steeper rake contribute to the its slightly quicker turn-in rate as well.

Meeting the road on the KTM is a set of Metzeler Sportec M5 Interact tires, in a 110/70 front and 150/60 rear combination. The Kawasaki makes use of Dunlop Sportmax GPR-300 tires—110/70 and 150/70. Both the Metzelers and Dunlops offer a good amount of grip on the street.

Should you be headed out for your first track outing, the stock tires will be fully adequate. If you want to invest in some track rubber that will be a sizing match for your motorcycle, you can opt for something like the new Bridgestone Battlax Racing R11.

The KTM RC 390 is packing some serious braking firepower for a motorcycle of its size. Equipped with a 320mm rotor accompanied by a radially mounted ByBre caliper (a Brembo subsidiary) that provides ample stopping abilities. Feel at the lever is good as well, giving great feedback when hard on the binders. At the rear, a 230mm rotor paired with a single-piston caliper provides adequate stopping power.

When riders start putting some serious heat into them and experience some fade, KTM did pony up for adjustable levers, allowing you to compensate for front brake (and clutch) fade, as well as the ability to adjust the levers to your liking.

The Kawasaki Ninja 400 binders definitely get the job done, even on track. Although they don’t quite have the KTM’s level of feel at the lever, they are good enough for expert riders and ideal for novices. Taking care of the Ninja is a 310mm petal rotor clamped upon by a conventionally mounted dual-piston Nissin caliper up front, with a 220mm rotor with a single-piston caliper at the rear. The Kawasaki’s brakes have excellent feel for mid-corner line corrections or low-speed maneuvering.

Both the models we tested here came equipped with ABS, however there is an ABS-free standard Ninja 400. Both systems do their job admirably. However, I found the KTM’s ABS to be less intrusive than the Kawasaki’s.

The KTM RC 390 is far and away the closest thing you’ll get to an authentic, larger displacement sport bike in the lightweight supersport category. An aggressive riding position with a longer reach to its clip-on style handlebars emulates what being aboard a proper supersport is like, without it becoming too uncomfortable.

The wide clip-on style handlebars contribute to a roomy cockpit on the RC 390 that allows for great maneuverability around the svelte fuel tank, not to mention leverage to spare. Its 32.3-inch seat-height makes for a riding position that encourages you to get over the front end, without putting too much weight on your wrists. You’ll find yourself sitting atop the bike, as opposed to in the chassis, which is somewhat typical of European sport bikes.

In a stark contrast, the Kawasaki Ninja 400 offers a more upright riding position, with narrower handlebars. With a nearly 31-inch seat-height, the rider is seated in the chassis, as opposed to atop. Coupled with a shorter reach to the handlebars, the result is a more upright or casual riding position.

I did experience much more knee bend aboard the Kawasaki with my 32-inch inseam. Despite that, moving around in the saddle of the 2018 Ninja 400 is a breeze, and the more relaxed riding position makes commuting a less taxing affair overall. Also, the Ninja 400’s lower seat height will make less experienced and shorter riders more confident when coming to a stop.

An oversight on the Ninja 400 is the placement of the muffler. Depending on the size of your boot, you might find your right heel at odds with the angle of the muffler. Luckily, aftermarket solutions exist to alleviate this problem.

The Ninja 400 draws visual inspiration from the larger motorcycles Ninja lineup. The 400 integrates aspects from the Kawasaki H2, such as the under-nose-spoiler, and the devilishly sporty headlights that are reminiscent of the ZX-10R and ZX-6R; something that riders new and old will appreciate. Other accoutrements such as the analog and digital display are simple and function well.

KTM has never been one to shy away from the bold, and the RC 390 certainly doesn’t fall far from the tree. Its angular styling received an update in 2017 and the RC 390 was given new plastic, graphics, and a side-mounted exhaust. In addition, the racy seat cowl doubles as a pillion seat, giving the tail section the uniform look of a proper track-ready Supersport.

In contrast to the Kawasaki’s excellent instruments, the RC 390’s LCD dash is small, difficult to read, and barely visible in direct sunlight. Aside from that, the shift light never seems to turn off while riding hard, until you figure out how to adjust it. There are small details that aren’t common in this class of bike, for example the back-lit hand controls, that make it much easier to see when riding at night.

The 2018 Kawasaki Ninja 400 ABS can be had for $5299 (add $200 for graphics or color upgrade), while the 2018 KTM RC 390 runs $5499. If you don’t want ABS on the Ninja 400, the price drops to $4999. We tested the Ninja 400 KRT Edition, which runs $5499 and has ABS.

Out of the box, the 2018 KTM RC 390 wears the brand’s Ready To Race motto on its sleeve. The more aggressive riding position, sporting-feeling inverted suspension, strong brakes, and adjustable ABS, suggest that this machine is just an upgraded set of tires away from being a competent track weapon. It has real strength in its rough-and-tumble single-cylinder engine. Without a doubt, it’s the closest approximation of a true supersport feel in this class, and will appeal to the more serious and experienced rider without being out of reach for those fresh to the saddle.

The 2018 Kawasaki Ninja 400 takes a different approach to the lightweight sportbike. Its more relaxed riding position, seriously willing engine, and stable, neutral handling stand at the forefront of the Ninja 400’s strengths. While it is no stranger to the track and will be a willing accomplice in turning its fair share of laps, the Ninja 400 sits as the more all-around option between these two machines; it’s great for the track, the canyons, and the commute.

Whichever suits you best, the 2018 KTM RC 390 and 2018 Kawasaki Ninja 400 are far beyond what was offered in this class just five years ago.

Photography by Don Williams and Kevin Wing

Riding Style

• Helmet: Shoei X-Fourteen Brink TC-5
• Jacket: Alpinestars T-GP Pro Air
• Gloves: Racer Mickey
• Jeans: Alpinestars Crank
• Boots: TCX Roadster 2

2018 KTM RC 390 vs. Kawasaki Ninja 400 ABS: Specs

2018 KTM RC 390 vs. Kawasaki Ninja 400: Photo Gallery