2021 Honda CRF450R and CFR450RX announced

WITH major overhauls of pretty much all the top-flight motocross bikes for 2021, it’s safe to say that Honda has also been burning the midnight oil in the quest for dirt bike supremacy.

Both the CRF450R and CRF450RX machines have undergone significant development, both for 2021 and in the last three years. The bikes now benefit from a new frame and swingarm, plus changes to geometry and suspension. A large weight-saving regime is also claimed to greatly improve cornering performance. The 2021 engine also receives intake and exhaust upgrades, a new decompression system plus a single exhaust muffler to boost and smoothen low-mid-range driveability. Here’s everything you need to know about the newly updated models.

Honda CRF1100L Africa Twin on and off-road review

Honda CRF450R features and updates

Chassis

The development theme for the 2021 CRF450R is described by Honda as ‘Razor-sharp Cornering’, helped massively by the new machine slimming down to the tune at 2kg – 112kg down to 107kg down to 105kg. The bulk of the weight saving is thanks to a revised frame and subframe, both of which have been optimised to work with a revised swingarm which is claimed to help boost rigidity, balance, and ground clearance.

Engine

Engine-wise, the power and torque of the 2021 version of the CRF450F is much the same as 2020’s bike. Instead, Honda has worked hard to make the engine more refined and useable, optimising the fuel injection, air-box, launch control and Honda Selectable Torque Control (that’s traction control to you and me) for the 2021 update.

There have also been significant updates to the new bike’s clutch, with the new bike featuring a large volume hydraulic unit, superseding the cable operated item on the previous bike. Honda claims the new system will improve the feel at the lever, making it more consistent, while also reducing rider fatigue.

The keen-eyed amongst you will also notice that the new bike features a single muffler, a move that alone saves over a kilogram in weight. Other exhaust revisions include a downpipe that sits 74mm closer to the bike’s centre line and twin resonators to reduce noise and help increase power.

Electronics

The CRF450R gained HSTC in 20YM and the system is unchanged for 21YM. It works to minimise rear wheel spin (thus wasted forward drive) and maximise traction. It doesn’t use a wheel speed sensor, and critically maintains feel at the throttle while managing power; ignition timing is retarded and the PGM-FI controlled when the rate of change of rpm is detected to have gone over a set amount.

The three Modes differ in drive management level for different riding conditions:

In Mode 1 the system intervenes most lightly, and after the longest time ¬– useful for reducing wheelspin and maintaining control in tight corners.

Mode 3 has the system intervene more quickly and strongly, and is therefore useful in more slippery, muddy conditions.

Mode 2 naturally offers a mid-point between 1 and 3 in terms of speed and strength of intervention.

An obvious update for 21YM is the rider controls and display switchgear. The Launch Control indicator, EFI warning, EMSB mode button and LED indicator - are sited on the left handlebar, with the HSTC button now incorporated.

Pressing and holding the HSTC button for 0.5s will cycle the system to the next mode, with a green LED indication - 1 blink for mode 1, 2 for mode 2, and 3 for mode 3 - to confirm the selection.

The HSTC system can also be switched off completely. When the engine is turned on, the system uses the last selected setting.

HRC Launch Control gives any rider the best option for a strong start and also has 3 modes to choose from:

Level 3 – 8,250rpm, muddy conditions/novice.

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

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

Activating HRC Launch Control is easy: to turn on, pull in the clutch and push the Start button on the right. The purple LED will blink once for Level 1 selection. Push the Start button again, for 0.5s or longer, and the LED will blink twice for Level 2. Repeat the process and the LED will blink 3 times, indicating that Level 3 has been chosen.

The Engine Mode Select Button (EMSB) alters the engine’s characteristics and three maps are available to suit riding conditions or rider preference:

Mode 1 – Standard.

Mode 2 – Smooth.

Mode 3 – Aggressive.

Honda CRF450RX updates

Like the CRF450R – pretty much every part of the CRF450RX is new for 2021. The new enduro sibling of the motocross CRF450R has received a comprehensive update benefiting directly from know-how gained by the development of Tim Gajser and HRC’s 2019 championship-winning squad. It's 2.3kg lighter and features a new frame and swingarm, plus changes to geometry and suspension, greatly improve cornering performance. The engine receives intake/exhaust upgrades, a new decompression system plus a single exhaust muffler to boost and smoothen low-mid-range driveability. A larger hydraulic clutch offers greater control with lighter lever pressure. More compact plastics and a smaller seat unit increase freedom of movement. Brush guards are now standard-fit and the side-stand tucks in more neatly for improved rider ergonomics.

Honda CRF450L (2021) specs – CRF450RX in brackets