The 2019 Honda CRF450RX was introduced in 2017 and based heavily on the CRF450R motocross bike. Since then, it's adopted the same updates as the motocross model and remains largely similar to it with the exception of the 2.25-gallon resin fuel tank, 18-inch rear wheel, kickstand, sealed chain, Dunlop AT81 tires, and different suspension settings.

Honda CRF450RX in front of mountain.
Weighing in at 257 pounds, the Honda is the heaviest bike in the shootout.Jeff Allen

2019 Honda CRF450RX Engine

Before the shootout began, we mounted a Dunlop D404 street tire on the rear wheel and ran the CRF on our in-house Dynojet dynamometer. The Honda cranked out 53.70 hp at 9,680 rpm and 33.17 pound-feet of torque at 7,710 rpm, ranking it first in horsepower and third in torque. After the dyno pulls were complete, we fitted Dunlop AT81 tires, as we did on all of the bikes to ensure consistency in traction among them for the entirety of the test.

Honda CRF450RX Dyno Chart
The CRF450RX produces the most horsepower of the four bikes in the test. It cranked out 53.70 hp at 9,680 rpm and 33.17 pound-feet of torque at 7,710 rpm.Jeff Allen

The 2109 Honda CRF450RX has the engine character of a fighter jet. It’s easily the fastest and most aggressive in the shootout. Its free-revving character combined with its light and responsive feel makes it the most exciting too. Engine-braking is minimal and the powerband is quite broad. It’s crisp off the bottom, barks in the midrange and top-end, and revs to the moon.

The engine runs best in the midrange to top-end, but is still very responsive at low rpm. It can easily be lugged and ridden a gear high, but when doing so and using the clutch excessively, it can fade and make the lever feel a bit inconsistent. Compared to the Yamaha YZ450FX, KTM 450 XC-F, and Husqvarna FX 450, the Honda's clutch pull is by far the heaviest. It's also the loudest bike with its short dual mufflers and large airbox openings.

Honda CRF450RX riding on dirt track.
The Honda’s engine is the fastest and most aggressive.Jeff Allen

The 2019 CRF450RX comes with a handlebar-mounted engine mode select button that has three preprogrammed maps—map 1 (standard), map 2 (smooth), and map 3 (aggressive). Map 1 has decent bottom-end and comes on strong in the midrange. Map 2 has less of a distinct hit in the powerband—almost traction control-like. Map 3 has the most bottom-end and is the easiest map to lug the bike low in the rpm, especially when riding a gear high. Most test riders preferred map 2 (smooth) as it offered more than enough power for off-road riding and vet motocross tracks. Despite being the mellowest of the three maps, the CRF was still a handful on tighter, technical trails, which was exacerbated by the stiff clutch pull.

2019 Honda CRF450RX Suspension

Similar to the engine, the Honda CRF450RX’s suspension is built for speed. The Showa 49mm coil-spring fork and Showa shock have a performance-oriented feel. The faster you ride the bike and the harder you push it, the better the suspension works. It lacks some sensitivity and comfort in the initial part of the stroke when hitting small bumps at lower speeds, but it excels when the speeds increase with good mid-stroke support and excellent bottoming resistance. The shock feels a touch stiff in comparison to the fork. Making adjustments to the Honda’s suspension should be done incrementally as just one click can make a noticeable difference.

Honda CRF450RX riding over boulders.
The Showa 49mm coil-spring fork and Showa shock have a performance-oriented feel.Jeff Allen

2019 Honda CRF450RX Chassis/Handling

The 2019 CRF450RX weighed in at 257 pounds on our automotive scales, making it the heaviest bike in the shootout. Contrarily, it’s the lightest-feeling and nimblest while riding. The bike has a smaller overall feel but not in a cramped sort of way—almost like it’s shorter than the three other bikes in the shootout. It corners the sharpest, but in turn gives up some stability on high speed, rough terrain. The Honda is very sensitive to setup. It has a noticeable high rear end stance and works well with 106mm to 108mm of shock sag.

One of the biggest differences the 2019 Honda CRF450RX has over all of the other bikes is its rear wheel traction. The design of the chassis puts so much weight on the rear wheel when accelerating—at times it’s unbelievable. Even on the steepest of hills, it continues to drive forward and resist trying to wheelie. The counter effect is that the front wheel can, at times, lose a little traction if you get lazy with your body position. With braking and cornering, it is very important to stay as forward as possible to maintain front wheel traction.

The Honda CRF450RX is slightly wider in the midsection and even more so in the fuel tank and radiator shroud area. The fuel tank is also tall. According to Honda, it was designed that way for safety requirements—to allow more airflow around the radiators and engine. Aside from that, the handlebar bend and position are agreeable, and so is the general rider position. Also, we like that the 2019 CRF450RX is equipped with a skid plate but would also prefer to see it come with hand guards in stock trim as well.

Honda CRF450RX kicking up dirt.
Even though the CRF450RX is the heaviest bike in the test, is the lightest-feeling and nimblest of the four bikes.Jeff Allen

Why It Should Have Won

The engine makes the most horsepower on the rear-wheel dyno and is the fastest on our seat-of-the-pants dyno. The suspension works well at for faster-paced off-road riding and on the motocross track. The CRF also offers the nimblest handling, sharpest cornering, and lightest weight feel.

Honda CRF450RX jumping in desert.
The Honda’s razor-sharp handling characteristics make it a bit unpredictable at times.Jeff Allen

Why It Didn’t Win

While the Honda can be the easiest to go fast on, it’s ultra sensitive to rider mistakes, which can make it unpredictable at times. The engine can be a bit too aggressive for tighter single-track riding and the clutch pull is the stiffest. The fuel tank is also fairly large and cumbersome, which has a negative effect on the cockpit with the wider front radiator shroud area.