Honda CRF450R

Model Update

Markus

28.05.2021

Photos: Honda

After a major evolutionary leap for model year 21, the CRF450R for the 22MJ gets further refinements and, thanks to new ECU settings, offers smoother handling as well as a new valve for the Showa suspension to improve the damping balance between the front and rear wheels. The frame remains unchanged and is exactly the same as that used in the CRF450RW, with which Tim Gajser became MXGP World Champion twice in 2019 and 2020.

1. Introduction

The Honda CRF450R has been the benchmark for motocrossers since its introduction in 2002. Their package has always been aimed at providing their driver – whether amateur enthusiast or professional racer – with total control through balance and agility. Plus, of course, it's built with the quality, durability, and durability that Honda has long been famous for.

It is a racing motorcycle that has constantly evolved. The 17MJ has been redesigned from scratch under Europe's most popular open-class MX machine under the "ABSOLUTE HOLESHOT!" development concept, with a completely new chassis and a significant performance boost at the top thanks to a brand new engine. The standard electric start was a practical addition to the MJ18. For the MJ19, a cylinder head developed by HRC significantly increased power and torque; the HRC Launch Control has also been added. For the 20th model year, the CRF450R received the Honda Selectable Torque Control (HSTC).

Apart from the wheels and basic engine architecture, the CRF450R in the MJ21 was effectively a completely new machine based heavily on the developments of the 2019 MX GP championship winner CRF450RW. And although the 2020 MXGP Championship was challenging for a variety of reasons, Gajser and HRC secured the title for the second year in a row at the 18th round in Trentino, Italy, in November 2020.

With this continuing proof of its top racing ancestry behind it, the CRF450R 22MJ has further refinements to the engine and chassis. And at its core, it remains an HRC racer that you can buy.

2. The model at a glance 

The revised CRF450R 21MJ was based on the development theme 'RAZOR-SHARP CORNERING', which focused on stronger torque in the lower and medium speed range, ultra-precise handling and driver-friendly ergonomics. The balanced stiffness of the new (2 kg lighter) frame and swingarm have been combined with tighter suspension geometry and increased ground clearance to achieve maximum cornering performance. The engine also benefited from HRC's know-how: the focus was now on torque in the lower to medium speed range. The decompression unit was relocated, the volume of the airbox was increased, the throttle body was revised and the outlet openings were reshaped. The exhaust manifold was also new, and a single silencer replaced the previous dual silencers.

A new hydraulic clutch and comprehensive electronics package provided better ergonomics that helped not only MXGP riders but also MX enthusiasts of all levels to drive consistently fast during a race.

Building on these solid foundations of the new 21 model, the CRF450R for the 22MJ will receive an ECU update that improves the drive, as well as a major overhaul of the Showa suspension front and rear that increases damping performance.

3. Essential features

3.1 Chassis

• On the 22MJ, tighter suspension damping ensures more balanced handling
• Narrow tubes on the main frame and a rear subframe save weight, using HRC's know-how
• Compact, narrow plastic parts improve the ergonomics of the driver

For the 22MJ, the chassis of the CRF450R is unchanged, except for adjustments to the Showa suspension front and rear. The goal for the 22 model year is to deliver a noticeably improved "hold up" – an increase in the compression damping of the stroke both front and rear – to optimize the balance between the front and rear wheels of the machine.

The Showa 49mm USD coil suspension fork AF2 is based on the "factory unit" delivered to MX racing teams in the Japanese Championship. The 21MJ update gave the fork 5 mm more stroke, to 310 mm, and increased stiffness for the axle clamps. For the 22MJ, the low-speed shim stack has been redesigned to achieve tighter settings for compression and rebound damping. The oil volume is reduced by 8 cm³ to 380 cm³; there are now 13 adjustment positions (instead of 15) for the rebound stage and 15 for the compression stage, as before.

A complete overhaul of the Showa MKE AF2 damper's low-mid and high-speed shims ensures a tighter overall setting of the pressure level damping. There are now 11 adjustment positions for the rebound (from 8 in the previous version) and 6 for the high and low speed compression (from 12). The oil volume increases by 1 cm³ to 422 cm³.
 
With the evolutionary leap of the 21MJ, the motorcycle parts and ergonomics have been greatly improved. Thanks to narrower main spars, the weight of the main frame could be reduced by 700 g, while the redesigned subframe also saved 320 g. The chassis dynamics have also been redesigned; while maintaining torsional stiffness, side stiffness has been reduced by 20% to increase cornering speed, traction and steering precision. Both the upper and lower triple clamps have been revised. They now offered more flex for faster steering and a better steering feel.

To increase the freedom of movement on the machine, the seat has been made shorter, lighter and 10 mm lower at the rear compared to the previous design. In addition, the ability to expand and install has been facilitated and maintenance has been simplified with only four 8 mm screws per side.
 
The radiator grilles are made of one piece of plastic and have a lower vent, while the radiator grilles are optimized for air flow. The titanium fuel tank holds 6.3 l.
 
The standard, lightweight Renthal Fatbar-Flex ensures optimum comfort; the upper triple clamp has two handlebar brackets that allow the handlebar to be moved 26 mm backwards and forwards. When the holder is rotated 180°, the handlebar can be moved another 10 mm from the basic position, resulting in four unique driving positions.
 

At the front, a double-piston brake caliper with a piston diameter of 30 and 27 mm and a 260 mm wave disc is used. Together with the brake hose with a low expansion rate, the system offers both an optimal pressure point and maximum stability. The rear single-piston caliper works in conjunction with a 240 mm wave disc.

 
The DID aluminium rims are painted black; at the front it is 21 x 1.6 inches, at the rear 19 x 2.15 inches. The rear wheel has been made both stronger and lighter for the 21MJ. Dunlop MX33F/MX33 Cross tyres are fitted as standard tyres.

 
Inclination and trailing remain at 27.1°/114mm with 1481mm wheelbase and 336mm ground clearance. The dry weight is 105.8 kg.

An eye-catching, new graphic concept completely in red underlines the now even sharper lines of the 2022 CRF450R.

3.2 Engine

• Revised ECU mapping for the 22MJ improves smooth power delivery
• Hydraulic clutch for smooth and easy lever feel
• Decompressor system ensures improved flow break-off resistance

On the 22MJ, the 449.7 cc four-valve Unicam engine remains unchanged, except for a revised ECU mapping that further promotes linear throttle response and improves power delivery.

The changes for the 21MJ were very significant. An increase (up to 0.6 kW) in peak power above 5,000 rpm – accompanied by a stronger sense of torque at low revs – was the result of an additional volume of 1.8 liters (to 4.1 liters) on the "clean" side.

The injection nozzle angle has been increased from 30° to 60°, which sprays the fuel in the opposite direction to the intake air in the direction of the throttle valve. This improves the intake efficiency, the cooling of the mixture and the important "throttle valve feeling" for the driver. Also new was the decompression system: its counterweight is shifted from the right side of the camshaft to the left, resulting in more stable operation at low speeds with less risk of dying.

The biggest change concerned the double outlet channels: as with the CBR1000RR-R Fireblade, its output became oval instead of round to improve efficiency. The manifold has also been mounted 74 mm closer to the center axle (which improves driver ergonomics), while the silencer is equipped with double resonators that both reduce noise and increase performance.

 
The hydraulic 8-disc clutch was taken directly from Gajser's motorcycle. It offers better control as well as an excellent feel at the gear lever and ensures an even lever stand even in difficult driving conditions. Slippage has been reduced by 85% at peak performance.
 
Bore and stroke are fixed at 96 x 62.1 mm with a compression ratio of 13.5:1. A gear position sensor allows the use of three specific ignition maps for the 1st and 2nd, the 3rd and 4th and the 5th. A 5-hole jet nozzle and a double 12 mm drum suction pump provide the necessary lubrication.

3.3 Electronics

• Honda Selectable Torque Control (HSTC) with 3 driving modes (plus OFF)
• HRC Launch Control offers 3 launch options
• Engine Mode Select Button (EMSB) offers 3 maps for setting the engine characteristics
  
• Improved HRC Setting Tool adjusts "aggressive" and "smooth" modes

The HSTC of the CRF450R works with the aim of minimizing the spinning of the rear wheel

(and thus the loss of propulsion) and maximizes traction. It does not use a wheel speed sensor and gets the driver's feel for the throttle while controlling power. As soon as the system determines that the speed change has exceeded a specified value, the ignition timing is delayed and the injection control is controlled via PGM-FI.

The three modes of the HSTC differ in the management of the drive for different driving conditions:

In mode 1, the system intervenes the least and at the latest – this is useful to reduce wheel spinning and maintain control in tight corners.

In mode 3, the system intervenes faster and more strongly and is therefore mainly used in slippery, muddy conditions.

Mode 2 naturally provides an average between modes 1 and 3 in terms of speed and strength of the intervention.

 
The Launch Control indicator, the EFI warning, the HSTC and EMSB mode button and the LED indicator are located on the left handlebar. By pressing and holding the HSTC button for 0.5s, the system moves to the next mode, with a green LED indicator - 1 flashing for mode 1, 2 for mode 2 and 3 for mode 3 - confirming the selection.
 
The HSTC system can also be switched off completely. When the motor is turned on, the system uses the last selected setting.
 
The HRC Launch Control offers each rider the best option for a strong start and also has 3 modes to choose from:
 

Level 3 – 8,250 revolutions per minute, muddy conditions/beginners.

Level 2 – 8,500 rpm, dry conditions/standard.

Level 1 – 9,500 rpm, dry conditions/expert.

Activating hrC Launch Control is easy: to turn it on, pull the clutch and press the start button on the right side. The purple LED flashes once for the selection of level 1. Press the start button again, for 0.5s or longer, and the LED flashes twice for level 2. Repeat the process and the LED flashes three times, indicating that level 3 has been selected.
 

The HRC-Launch Control is easy to activate: turn on, pull the clutch and press the start button on the right. The purple LED flashes once to select level 1. After pressing the start button again for 0.5 s or longer, the LED flashes twice for level 2. After repeating the process, the LED flashes three times, indicating that level 3 has been selected.

The Motor Mode Radio Button (EMSB) changes the characteristics of the motor. Three maps are available to take into account driving conditions or driver preferences:

Mode 1 – Standard

Mode 2 – Soft

Mode 3 – Aggressive

 
The LED also indicates the selected mode, but with a blue light.
 
The HRC adjustment tool can activate a much easier smooth mode, including a smoother throttle response for beginners in this performance class. It can also program the aggressive mode with a very sensitive throttle response and direct engine response for racing conditions into the engine control.

4. Technical data

All specifications are preliminary and subject to change without notice.