The 2017 CRF450R is all new-from-the-ground-up. A new Unicam engine offers increased power and torque across the rev range, thanks in part to an ultra-direct downdraft air intake, steeper valve angle and twin exhaust system with smoother routing. The chassis boasts new geometry and packaging that results in a more concentrated, lower center of mass, helping to get the power to the ground, maximize stability and improve cornering performance. The lighter aluminum frame has a narrower cross-section and a lighter, extruded aluminum rear subframe. The motorcycle is equipped with a coil-spring 49mm Showa A-Kit fork, while the rear suspension comprises a lighter swingarm assembly and a shock with a lower mounting position. Dunlop Geomax MX3S tires come standard, and the CRF450R is the first mass-produced motocross bike ever to come with a titanium fuel tank. The weight is said to be 233 pounds, which is the same as last year. The chassis lost weight, while the spring forks added. Electric start is available as an option for around $650, although that does not include the battery. The same electric stater comes standard on the 2017 CRF450RX
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.
2017 HONDA CRF450RX
As a brand-new model, Honda’s CRF450RX boasts most of the features of its motocross-directed sibling, but in a package that’s designed for closed-course off-road riding and racing. Among the features that distinguish it from the CRF450R are a smoother ignition map and standard electric start (with kick-start backup), while chassis differences include off-road-focused suspension settings, a revised cylinder-head hanger and changed wheel hubs and axles. The CRF450RX also comes with off-road-appropriate components like a larger plastic fuel tank, forged-aluminum side stand, 18 inch rear rim and Dunlop Geomax AT81 tires, making it the ultimate weapon for events like those in the GNCC series.
