The CBR500R engine lines up right between the two Ninjas, notable for its flat torque curve and linear power.
The Ninja 300’s 296cc Twin is the most oversquare of the bunch, sporting a 62mm bore and 49mm stroke. All of the extra displacement gained by the 300 came via a longer stroke, up front 41.2mm. But Kawasaki engineers retained the old 250’s high-revving 13,000 rpm redline thanks to a host of internal updates including new cylinders, pistons and connecting rods, as well as enhanced engine cooling to handle the extra heat generated by the increased power.
Honda’s Parallel Twin is a completely new design shared by the entire CB500 lineup. It is technically oversquare, but by the slimmest of margins with a 67mm bore and 66.8mm stroke – the bore/stroke ratio 1.003, compared to the 1.265 Ninja 650 and 1.383 Ninja 300 (down from 1.626 on the 250 predecessor). Tuned for street-friendly torque, the CBR mill redlines at 8500 rpm – a full 2500 less than the nearest bike, the Ninja 650R.
As for the bigger Ninja, its 649cc Twin debuted in 2006 – a long-running platform that’s powered the Ninja 650 as well as the Versys and short-lived ER-6n (short-lived, at least, in the US market). The 2012 model year saw the engine get a reshaped piston, revised timing and tweaks to the exhaust system. The 83mm bore and 60mm stroke have never been altered.
Up on the dyno, the three bikes register in the expected order. The bigger Ninja sports the punchiest torque curve, maxing out at 43.21 lb-ft at 7100 rpm. There’s more horsepower everywhere, even after the 650 falls flat well before the 11,000 redline peaking at 8800 revs with its 63.71 hp. The Honda CBR does its thing, cutting right between the Ninja power curves – topping out at 42.9 hp and 29.19 lb-ft. However, the CBR torque curve is remarkably flat, producing 25 lb-ft right off the bottom with its peak horsepower coming right at redline. Meanwhile, the spunky Ninja 300 manages 17.85 lb-ft torque at 9800 rpm, with the 35.41 horsepower max coming in at 11,200 rpm. Those higher revs for the 300 give the Ninjette a disproportionately higher power production per cc, with the 500 slightly closer to the smaller Ninja than the 650 in peak numbers.
The dyno charts are a fair evaluation of how the engines perform out on the street. The different natures of the 300 and 500 are immediately apparent. The Honda churns out a steady beat of torque everywhere, including right off idle. A perceptible boost kicks in between 6 to 8K, but the overall power delivery is mind-numbingly linear. There are no flat spots, where power drops off, zero.
The Ninja 300 presents a much different powerband than the steady CBR500. The little Ninja’s high-strung Twin begs to get throttled up into five-digit territory on the tach where its starts to close the performance gap on its larger rival.
The little Ninja, on the other hand, sports a whole different demeanor. While low-end power has improved compared to its 250 predecessor, the 300 feels sluggish off the bottom compared with the larger-displacement Honda. What it can do, however, is scream its little head off as is revs up to the top end where it starts to make up ground. The Ninja 300 prefers to get wringed out to 9K (well past the CBR redline) and kept zinging in the five-digit rpm range. Even then it still can’t match the Honda, but it sure is a blast to flog up on the surging top-end.
Compared with the smaller bikes, the 650’s 63 ponies at the rear wheel are downright menacing. There’s more power everywhere, with a sweet spot between 6 to 9K. Intermediate riders will appreciate the 650 Twin as playful and snappy, but raw recruits may find the punchy engine a bit too much.
“The 650 seems like an obvious step into an intermediate level of riding skill and perhaps not geared for the legitimately new rider. There’s power there that needs to be managed,” notes our resident newbie, Byron.
The bigger Ninja’s livelier throttle makes it a more challenging ride than the forgiving 300/500 duo. The 650 Twin can hoist the front wheel with some aggressive smacks on the throttle – and newbies do need to tread lightly. This contrasts the Honda, whose throttle response is so composed its hypnotic. The 300’s fueling and throttle input is closer to the Honda than its bigger sibling, but it lacks the CBR’s refinement. The Honda’s smoother throttle and steady fueling is one of its entry-level highlights, without any disconcerting herky-jerky inputs it encourages rider confidence and an easy, flowing riding style.
The CBR50R engine features a smooth steady draw of power from its 471cc Parallel Twin, which makes for an easy ride.
The Honda is also easy to launch with its well-sorted six-speed gearbox. The seamless clutch engagement and gentle throttle make for a brilliant beginner bike transmission.
“Power delivery was always smooth,” confirms Byron. “I thought the transmission was the best of the bunch; there was hardly a discernible moment of power transfer when releasing the clutch, it just flowed. Also it was nice to have more engine power on tap compared to the 300 because you didn’t have to move so quickly through the gears during those stop-and-go moments.”
Riders do have to shift more often on the revvy little Ninja. This includes lots of downshifts – which are smoothed out by the surprising slipper clutch. It’s a marquee spec advantage for the Ninja over its Honda rival, and one which likely goes underappreciated by beginner riders who won’t notice how much its benefitting them. Our testers found the 300’s clutch engagement, toward the end of the lever, not as preferable as the Honda – but that’s a complement to the CBR, not a dig on the Ninja.
The Ninja 650’s transmission, however, is far less polished than the smaller rides. The gearbox is particularly rough around the edges, notchy enough even for our least experienced rider to call it out.
“Compared to the Honda, the Ninja 650 transmission felt a little clunky. It also required smooth inputs from the throttle and levers. I had a few oh-s%^& moments when I let the clutch out too fast or pulled the throttle too hard,” admits Byron.
Real world performance on the freeway finds the CBR500R stretching its legs out easier than the 300. The little Ninja has no trouble blitzing around the usual superslab impediments, like lurking semis or fast-lane hogging SUVs, but it’s not as effortless as the twist-and-go torque offered by the CBR. On back roads the two bikes offer paradoxical performance, with the Honda’s extra cc and flat torque curve delivering better acceleration but the 300 seeming sportier thanks to its top-end bias and frenetic gear-shifting pace.
At the pump, the smaller displacement mounts sipped a near identical amount of fuel – at 53 and 54 mpg. The nod here goes to the CBR, but it’s really a wash between the two. The larger CBR may burn more fuel with each engine cycle, but the 300 revs more frequently because of its higher rpm ceiling. (Having participated in the Ninja 300 mpg fuel challenge during the first ride press introduction, we personally can vouch for the high 80s and even witnessed triple digit mpg efficiency for more frugal throttle hands.)
The Kawasaki’s extra 0.4 gallons in its 4.5-gallon tank does bequeath a slim 18-mile advantage in estimated range, at 239 miles, but the CBR can still comfortably exceed 200 miles between fuel stops. The 650, unsurprisingly, registered a more down-to-earth 37.5 mpg during our testing – which factors into a 157-mile range.