2017 CRF450R

Believe it or not, it has been 15 years since the introduction of the first-generation CRF450R motocross bike. This bike been a huge success on the showroom floor, and in competition around the world.

 

 

For 2017, Honda has completely revamped the big CRF from top to bottom. Among the changes are an all-new Unicam engine with improved power and torque across the rev range. Significant changes to the cylinder head include the use of a finger rocker arm for increased valve lift, and oval-coil cross-section valve springs, the combination of which allows a lower engine height, plus makes the mill more compact and gives it a lower center of gravity.

 

 

Additionally, the head has a narrower included valve angle (reduced from 21.5 to 19.5 degrees) for a straighter shot into the combustion chamber and improved burn from the mixture. Intake valves are now 2mm larger at 38mm. A new piston combined with a revised combustion chamber raises compression from 12.5 to 13.5:1, new four-hole oil jets for piston lubrication, and a new dual-stage scavenge pump reduce friction enough that oil volume has been reduced from 1,490 to 1,250cc; the lubrication system no longer uses two different oils and reservoirs for engine and gearbox. A new clutch, airbox, and exhaust system round out engine changes, while transmission ratios and final-drive gearing have been altered for the new spread of power.

 

Another piece of big news is that electric starting will be available as a $650 optional kit (sans battery). The owner can choose which battery they would like to use. With all the effort Honda has made to reduce weight on the bike, we assume that most consumers will go for an ultra-light lithium-ion unit.

 

 

While the engine received a lot of attention, the chassis wasn’t left alone either. Efforts were made to improve cornering balance, increase rear-wheel traction, lower the center of gravity, and improve mass centralization. The frame is now the sixth generation of Honda’s aluminum twin-spar frame and has been tweaked for improved cornering performance.

 

 

Suspension has been totally rethought and has a new 49mm Showa fork up front with coil springs in place of the previous air fork. The shock is now mounted 39mm lower in the chassis making room for a more direct intake funnel from the airbox to throttle body. A new swingarm is lighter, stiffer, and slightly shorter. Fork angle has increased from 27.1 to 27.4 degrees, while trail has been increased by 1mm; the wheelbase has shrunk from 1,492 to 1,481.5mm.

 

 

Another cool feature on the R is the use of an all-new titanium fuel tank. Not only is the tank slightly lighter while carrying the same 1.6 gallons of fuel, but it’s also now lower in the frame for an improved center of gravity. The bodywork is all-new and now has in-molded graphics, so you won’t be blowing off the decals with your zillion-psi pressure washer.

 

 

 

CRF450R Specification

ENGINE TYPE	449.7cc liquid-cooled single-cylinder four-stroke
BORE x STROKE	96.0 x 62.1mm
COMPRESSION RATIO	13.5:1
INDUCTION	Programmed fuel-injection system (PGM-FI); 46mm throttle bore
IGNITION	Full transistorized ignition
TRANSMISSION	Constant-mesh 5-speed return
FINAL DRIVE	520 chain; 13T/49T
VALVE TRAIN	Unicam® OHC, four-valve; 10.0mm intake, steel; 8.8mm exhaust, steel
FRONT SUSPENSION	49mm fully adjustable leading-axle inverted telescopic Showa coil-spring fork; 12.0 in. travel
REAR SUSPENSION	Pro-Link swingarm system; fully adjustable Showa single shock; 12.4 in. travel
FRONT BRAKES	Single 260mm hydraulic disc
REAR BRAKES	Single 240mm hydraulic disc
FRONT TIRES	Dunlop Geomax MX3S 80/100-21 55M with tube
REAR TIRES	Dunlop Geomax MX3S 120/80-19 55M with tube
RAKE (CASTER ANGLE)	27°22’
TRAIL	116.0mm (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	243 lbs.

 

 

2017 Honda CRF450RX

While unveiling the brand-new 2017 CRF450R motocrosser to the motorcycle media gathered at Honda’s private museum in Torrance, CA, Honda surprised us when off-road legend Johnny Campbell rode a brand-new model called the CRF450RX into the presentation area.

 

 

The CRF450RX is essentially the same motorcycle as the R with a few additional changes made for off-road competition. Key alterations include an 18-inch rear wheel/tire combination, a one-tooth larger rear sprocket for a lower final-drive ratio, off-road specific Dunlop Geomax AT81 tires, revised suspension damping front and rear, and a lighter spring on the shock.

 

The engine is identical to the new mill housed in the CRF450R, with a finger rocker arm for increased valve lift, new piston, larger intake valves, and narrower included valve angle, but has revised engine mapping tuned for off-road riding. Whereas electric starting is a $650 option on the MXer, it comes standard on the RX, albeit with a heavy Grom-derived AGM (absorbent glass mat) battery. Fuel capacity has been increased from 1.6 to 2.2 gallons, but gone is the R’s trick titanium fuel tank replaced by a molded plastic unit. A forged aluminum sidestand is also fitted as standard.

 

As with the R model, we don’t expect the RX to arrive in dealerships until the end of October, when it will join the new CRF450R, and continuing CRF450X on the showroom floor.

 

 

CRF450RX Specification

 

ENGINE TYPE	449.7cc liquid-cooled single-cylinder four-stroke
BORE x STROKE	96.0 x 62.1mm
COMPRESSION RATIO	13.5:1
INDUCTION	Programmed fuel-injection system (PGM-FI); 46mm throttle bore
IGNITION	Full transistorized ignition
TRANSMISSION	Constant-mesh 5-speed return
FINAL DRIVE	520 chain; 13T/50T
VALVE TRAIN	Unicam® OHC, four-valve; 10.0mm intake, steel; 8.8mm exhaust, steel
FRONT SUSPENSION	49mm fully adjustable leading-axle inverted telescopic Showa coil-spring fork; 12.0 in. travel
REAR SUSPENSION	Pro-Link system; fully adjustable Showa single shock; 12.3 in. travel
FRONT BRAKES	Single 260mm hydraulic disc
REAR BRAKES	Single 240mm hydraulic disc
FRONT TIRES	Dunlop Geomax AT81 90/90-21 with tube
REAR TIRES	Dunlop Geomax AT81 120/90-18 with tube
RAKE (CASTER ANGLE)	27°22’
TRAIL	116.0mm (4.6 in.)
SEAT HEIGHT	37.8 in.
GROUND CLEARANCE	12.9 in.
WHEELBASE	58.1 in.
FUEL CAPACITY	2.2 gal.
COLOR	Red
CURB WEIGHT	261 lbs.

 

If you own a CRF450R, you can find custom parts here >> Custom parts CRF450R <<

 

Information Source: Cycle World and Honda

 

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