Motorcycle specifications HondaCRF 450 RX 2019 A wider path

In 2017, Honda presented an all-new enduro machine, the CRF 450 RX. A machine that took over the engine and chassis base of the 2017 CRF 450 R, the first total redesign of this bike in eight years.

Today, just as the 2019 CRF 450 R benefits from numerous evolutions dictated by HRC's experience, the CRF 450 RX follows the same path and increases its level of performance to become an even more efficient and field-friendly machine.

As with the CRF 450 R Motocross, the torque and power ratings of this Enduro version have received a major boost, while performance has been improved across the entire range.rider now has access to a three-mode Start Assist system directly inherited from HRC. The 2019 chassis features reworked stiffness, modified suspension settings and a new Renthal Fatbar adjustable handlebar.

honda CRF 450 RX highlights

For its 2019 model year, the CRF 450 RX raises its performance level even further. Significantly higher power and torque figures have been extracted from the engine thanks to in-depth work carried out in accordance with HRC guidelines on the cylinder head, intake and exhaust. All without compromising low-speed traction.

A three-mode start-assist system directly inspired by that used by Honda's competitiona three-mode start-assist system, directly inspired by that used by Honda's competition department, has been installed to help the driver - whether beginner or expert - to extract himself instantly from the grid at every start. An engaged-gear sensor provides gear-specific ignition mapping, while the PGM-FI injection system has been optimized to inject twice per cycle. Oil pump capacity has been increased, and some clutch components (control rod and pressure plate) redesigned.

The aluminum double-beam frame remains largely unchanged, but its construction has been modified to save weight, as has the swingarm. A new front brake caliper also saves a few grams.

On the suspension front, new hydraulic settings and new spring rates have been applied to the inverted fork.the ø 49 mm Showa inverted fork is now more responsive. at the rear, the monoshock benefits from a 'Super Finish' treatment and revised ratios for the Pro-Link variable gearing system.

Finally, an adjustable Renthal Fatbar is now standard equipment.

more details on the 450 RX :

engine

Although the general architecture of the 449 cm3, 4-valve Unicam single-cylinder engine remains largely unchanged, a host of new details enable the 2019 CRF 450 RX to claim increased power and torque figures.

And while the gains are significant (+ 1.8 kW at 9,500 rpm and + 2 Nm at 7,500 rpm), they have not been achieved at the cost of a drop in low-end performance. In the end, the power and torque curves are significantly strengthened above 3,000 rpm, while the ability to stay on the edge of the red zone between bends has also been improved.

Fundamental bore and stroke dimensions remain fixed at 96 x 62.1 mm, with a volumetric ratio of 13.5 to 1. The shape of the combustion chamber squish zone has been revised, as have the piston skirt, piston rings and connecting rod. The outer casings have also been reworked to achieve a better balance between weight and strength.

A new air filter support doubles the filtration surface area, allowing much more air to pass through to the engine. PGM-FI electronic fuel injection settings have been adapted accordingly, and the system now injects twice per cycle. To further enhance engine performance, a new radiator grille optimizes air flow for greater efficiency.

Finally, a sensor installed on the gearbox enables 3 specific ignition maps to be used depending on the gear engaged (first and second, third and fourth, fifth).

The exhaust system has also evolved, with a difference in diameter between the tubes between the manifold and the exhaust pipe.between the main manifold and the mufflers: the right-hand tube has a diameter of 35 mm, while the left-hand tube has a diameter of 42 mm
(ø 31.8 mm for both tubes previously). At the same time, the overall length of the exhaust line has been increased by 187 mm on the left-hand side, while the right-hand silencer is 98 mm longer.

Despite this long list of developments, it's not all about performance. Reliability has always been an important factor for the CRF 450 RX. A new 5-nozzle oil jet replaces the previous 4-nozzle component to cool the piston, while the oil pump, which previously used a single ø 16 mm suction nozzle, now makes use of 2 ø 12 mm elements, synonymous with greater capacity.

As for the transmission, several clutch components have been redesigned for greater strength, while the newthe 5-speed gearbox features a 13 x 50 final drive, and the crown gear has been redesigned for greater lightness.

The ignition switch, EMSB (Engine Mode Select Button) map selector, injection warning light and LED are integrated into a small comodo on the left of the handlebars.

New for 2019, the Launch Control system developed by HRC allows the rider to choose from three start modes.
- Mode 3 / 8,250 rpm, particularly suitable for beginners and/or muddy conditions
- Mode 2 / 8,500 rpm, for advanced riders and dry conditions
- Mode 1 / 9,500 rpm, for expert riders and dry terrain

Activating the HRC Start Assist system is simple: just engage the clutch and press the starter button. An LED will flash once to indicate that mode 1 is active. If the starter button is pressed a second time for 0.5 seconds or more, the LED will flash twice to indicate that mode 2 is engaged. Press it again and the LED will flash 3 times to indicate that mode 3 has been selected

The Honda EMSB (Engine Mode Select Button) system adapts the engine's character to the rider's requirements. With the motorcycle static and the engine at idle, a single press and hold on the dedicated switch for less than a second selects the next map in the sequence.

After a quick press, as with Launch Control, the LED on the switch indicates the current map: one flash for mode 1, 2 flashes for mode 2... If a new map is selected, the choice is also confirmed to the driver three times.

Mode 1, the standard mode, selects the optimum combination to deliver an effective balance between power and torque. Mode 2 is gentler, with a more progressive throttle feel. Finally, mode 3 offers more responsive behavior, with more aggressive, instantaneous power. Modes 2 and 3 can also be modified using HRC's map-setting system.

cycle

The objective of the 7th-generation double-beam aluminum frame developed for the CRF was clear: optimize cornering efficiency, front-end stability and grip, and rear-end steering, all with a high level of feedback to the rider.

And while the 2019 model's evolutions focus on engine power and control, the chassis has not been forgotten.the chassis has also been improved, with even better overall balance and enhanced agility and traction. Suspension operation has also been revised, both front and rear.

Total weight has been reduced by 900g to 109.5kg dry, or 115.6kg in running order. Caster angle and drag are set at 27.4°/116 mm, with a wheelbase of 1,477 mm.

The aluminum double-beam frame is now narrower and lighter, particularlythe swingarm has also been modified to improve feel and grip, but also to save weight.

The rigidity of the 2 cylinder-head mounting plates (left and right) has been optimized, while the structure of the swingarm rests has been modified.while the structure of the footrests has been modified, going from 6 to 4 reinforcements for a weight saving of around 20%.

Fully adjustable, the Showa ø 49 mm inverted fork with springs is simply a version of the Showa factory kit supplied to official Japanese MX Championship teams. For 2019, the spring rate, hydraulic compression and rebound adjustments and oil volume have been modified. at the rear, the fully adjustable Showa monoshock receives a 'Super Finish' treatment to improve its travel performance. Last but not least, new ratios for the Pro-Link variable gearing system significantly smooth the shock's operation as it approaches the compression stop.

The new Renthal Fatbar - with protective foam - helps to reduce steering weight while enhancing rider comfort thanks to its flexibility. The fork crown is designed to allow the 26 mm handlebar mounts to be moved forwards or backwards. When the mounts are rotated 180°, the handlebars have an additional 10 mm of latitude, bringing the number of riding positions available to the rider to 4.

As on the 2019 CRF 450 R, the front brake caliper is of a new, lighter type, with ø 27 and 30 mm pistons compared with 2 x 27 mm in the past. This evolution, combined with the adoption of a new low-expansion hose, improves braking feel and maintains power at a constant level. The new caliper acts on a ø 260 mm petal disc, complemented at the rear by a ø 240 mm disc with single-piston caliper.

The DID aluminum wheels (1.60 x 21 at the front and 2.15 x 18 at the rear) are now black anodized. Both are fitted with Dunlop Geomax AT81 tires in 90/90-21 front and 120/90-18 rear.

Like the CRF 250 RX, the 450 gets an 8.5-liter plastic fuel tank. The radiator gills are specifically designed to allow the rider to move easily around the machine, while the narrowness of the front end and the shape of the mudguard direct air more efficiently towards the radiator, whose grille has been redesigned to facilitate airflow.

The trim is integrated directly into the plastic components, making it highly resistant to friction.

News and media credits: Honda