Honda officially pulled the wraps off its 2017 CRF450R motocrosser, revealing an, as expected, all-new motorcycle. Everything has been changed: motor, chassis, suspension, plastic, graphics… It’s the first major change to the CRF450R since the 2013 model.
Honda uses the term “Absolute Holeshot” a lot when it comes to the ’17 CRF450R. You might be quick to think “launch control” but Honda has not fitted the bike with such a thing but instead designed the entire bike—among many other things—around getting the holeshot on the track, which is a very important part of racing, they say, and we can’t disagree. Honda designed the chassis and engine to better deliver power to the rear wheel and, more importantly, to the ground.
For many, though, the biggest news is Honda going back to a more traditional and less complicated (to adjust and maintain) spring fork. It’s made by Showa and is the same fork as Showa’s 49mm race-kit fork. Yes, it is heavier than the previous air fork but a lighter frame makes up for the difference. Claimed curb weight is the same as the 2016 CRF450R at 243 pounds.
The all-new motor still utilizes Honda’s Unicam valvetrain but has been completely reworked. It’s more compact, as well. Honda claims that intake efficiency is up 19% and exhaust efficiency is up 10%.
There is a new piston and compression ratio is up from 12.5:1 to 13.5:1. A new four-hole piston oil jet keeps the higher-compression engine running cool. There is also a new dual-stage scavenge pump oil lubrication system—there’s only one oil system now which greatly simplifies maintenance (oil changes).
Another big change is the location of the airbox—it’s now positioned high up in the frame. This allows for a straight shot of air to the combustion area; the intake track no longer has to wiggle around the upper shock body, which is also shorter in length to compensate for the shock mount being positioned 39mm lower than before). There are other benefits of the new airbox position—the exhaust pipe has more gradual bends for smoother exhaust flow and to help achieve a higher compression ratio. Honda made the dual mufflers even more compact than they already were.
The clutch has also been modified; it’s more compact and uses one less plate (though thickness has been increased) and spring. Primary ratio has been revised, as well. Overall, it’s a smaller clutch with the same lever load. Transmission ratios—internal and external—have been changed, too.
Honda offers electric starting for the CRF450R as an option—it’s not standard equipment. Instead, you can purchase a kit from Honda for approximately $650, which does not include a battery. It’s said to add about six pounds when installed.
Overall, Honda says that the new engine is higher revving, has increased torque across the range and more peak horsepower (about 60 measured at the crank).
The CRF450R has a new frame that is claimed to improve balance for cornering, increase rear-wheel traction, lower the center of gravity, and better-centralizes weight.
The rear shock is now centered right in the middle of the chassis; before, it was 5mm off-center. Honda claims that the centered placement is better for centralizing mass weight.
The swingarm is new and is .49 pounds lighter.
The fuel tank is now made out of titanium and is .13 pounds lighter than the previous plastic tank. Capacity remains the same at 1.6 gallons.
Honda also saved a little weight by combining the stop switch and the map switch into just one switch, which is mounted on the left handlebar.
As you can see, body works is all new. Not only is it shaped differently, but it’s also 30mm narrower at the radiator shrouds. The surface is also smoother for easier fore and aft movement. Graphics are now in-molded.
The wheels, which are about the only thing unchanged, come fitted with Dunlop Geomax MX-3S tires.
Here is what Honda says about its new CRF450R:
Since its 2002 introduction, the CRF450R has earned an enviable racing pedigree, and the 2017 edition is the best yet, with superior technology and style. Riders know that the most important part of any motocross race is the start, and the new CRF450R Unicam® engine has been developed to achieve overwhelming performance in the first 100 feet of battle, offering increased power output but also allowing unparalleled traction. And while arriving to turn one first is significant, winning requires staying in front for the entire moto, which is why Honda engineers designed an all-new chassis with reduced weight and centralized mass. The result is a machine that is at once fast, reliable and forgiving, and that allows riders to more easily extract maximum performance, consistently turning low lap times while simultaneously taxing their bodies less.
Engine/Drivetrain
- Downdraft intake layout increases power by reducing resistance, improving air-charging efficiency.
- New combustion chamber with higher compression ratio, decreased valve angle for greater efficiency.
- Use of finger rocker arm allows increased valve lift while retaining compact Unicam layout.
- Coils on valve springs have oval cross-sections to allow low engine height.
- New port layout with straighter flow for increased efficiency.
- New piston with improved combustion efficiency.
- Diamond-like carbon (DLC) on piston pin, rocker arm reduces friction, increases durability.
- New, compact dual muffler with more-gradual pipe bends for smoother exhaust flow.
- Shallower clutch assembly with fewer, thicker plates for narrower engine width.
- Kick start standard, with electric start available as an accessory.
Chassis/Suspension
- New layout allows improved traction through concentration of mass, lower center of gravity.
- New, lighter sixth-generation aluminum twin-spar frame with revised geometry; allows improved cornering performance through reduction of torsional stiffness (lateral stiffness is unchanged).
- New, lighter swingarm assembly with increased vertical and lateral stiffness.
- New rear-suspension location lowers center of gravity.
- Narrower cross section (down 30mm at radiator shrouds).
- Aluminum rear subframe with extruded gussets for lighter weight.
- Showa fork is now 49mm (up 1mm), with coil springs replacing air system.
- New, lighter titanium fuel tank.
- Kill switch/ignition-map-adjustment switch combined into one unit for reduced weight.
- Dunlop Geomax MX3S tires.
- Plastic bodywork with smoother layout and film-insert graphics for improved appearance and durability.
- New front fender shape allows more-efficient air path to radiator.
- Meets current CARB and EPA emissions standards
2017 Honda CRF450R
SPECIFICATIONS
ENGINE TYPE Liquid-cooled, single-cylinder 4-stroke
DISPLACEMENT: 449.7cc
COMPRESSION RATIO: 13.5:1
INDUCTION: Programmed fuel-injection system (PGM-FI), 46mm throttle bore
IGNITION: Full transistorized ignition
TRANSMISSION: Constant-mesh 5-speed
FINAL DRIVE: 520 chain; 13T/49T
VALVE TRAIN: Unicam OHC, 4-valve; 10.0mm intake, steel; 8.8mm exhaust, steel
FRONT SUSPENSION: 49mm fully adjustable leading-axle inverted telescopic Showa coil-spring fork
REAR SUSPENSION: Pro-Link swingarm system; fully adjustable Showa single shock
FRONT WHEEL TRAVEL: 12.0 in.
REAR WHEEL TRAVEL: 12.4 in.
FRONT BRAKE: Single 260mm disc
REAR BRAKE: Single 240mm disc
FRONT TIRE: Dunlop Geomax MX3S 80/100-21 in.
REAR TIRE: Dunlop Geomax MX3S 120/80-19 in.
RAKE: 27°22’
TRAIL: 4.6 in.
SEAT HEIGHT: 37.8 in.
GROUND CLEARANCE: 12.9 in.
WHEELBASE: 58.3 in.
FUEL CAPACITY: 1.6 gal.
COLOR: Red
CURB WEIGHT (wet, full fuel): 243 lbs.
