The Honda CRF450R has been the benchmark motocrosser since its introduction in 2002. The package it offers has become a byword for balance and agility, and as such has consistently offered its rider - whether amateur enthusiast or pro-racer - total control and the chance to get the very best from their ability.
It’s a machine that has constantly evolved, with every upgrade - large or small - drawing on lessons fed back from Honda’s racing programmes throughout the world. In 17YM, under a development concept of ‘ABSOLUTE HOLESHOT!’, Europe’s favourite open-class MX machine was given a ground-up redesign, with completely new chassis and a major top end power boost from a brand-new engine.
The 20YM CRF450R gained Honda Selectable Torque Control (HSTC), and provided the base for the CRF450RW HRC race machine ridden to the 2019 MX GP World Championship in the expert hands of #243 Tim Gajser. The 21YM CRF450R draws heavily on what he, and HRC, learnt on their long road to overall victory in 2019.
For 21YM the CRF450R receives a wide array of improvements and upgrades under a development theme of ‘Razor-sharp Cornering’. Firstly, it’s 2kg lighter, thanks to a revised frame and subframe. The new frame and swingarm’s rigidity balance, combined with tighter chassis geometry, heightened ground clearance and suspension changes, are all targeted at creating optimal cornering performance. Learnings from Tim Gajser’s championship-winning 2019 campaign reduce rider fatigue, allowing enthusiasts of all ability levels to consistently post optimal lap times.
The engine also benefits from HRC’s knowhow to give a strong focus on low- to mid-range torque. The decompressor has been relocated, airbox volume is up, the throttle body redesigned and exhaust ports re-shaped. The exhaust downpipe is new and a single muffler replaces dual mufflers.
A larger-volume hydraulic clutch has an even lighter lever action, while other weight-saving details include a smaller fuel pump and optimised magnesium cylinder head cover. New plastics, too, are lighter and slimmer to aid rider freedom and the seat is a smaller unit, lower at the back. A smart new all-red graphic scheme completes this major update.
The CRF450R’s twin-spar aluminium frame was unchanged in 20YM; for 21YM it is completely renewed – with direct input from the HRC race team – to elevate every aspect of cornering ability.
Thanks to narrower main spars, at 8.4kg it weighs 700g less than the previous design, while a redesigned subframe also saves 320g at 910g. The chassis dynamic is also new: while torsional rigidity is maintained, lateral rigidity has been reduced by 20% to increase corner speed, traction and steering accuracy. The aluminium swingarm has a new rigidity balance tuned to match the frame, with narrower arms and pivot point. The Pro-Link ratio is also revised.
Both top and bottom yokes are revised, with more flex, for quicker steering and feel. Fully adjustable, the 49mm Showa USD coil spring fork is a version of the Showa ‘factory’ fork supplied to MX race teams in the Japanese championship. With the target of improved, smoother cornering performance, the forks have been revalved, the stroke lengthened by 5mm to 310mm and the axle clamps’ rigidity increased. The Showa rear shock’s main piston valving is enlarged for faster response and improved bump absorption. Its spring also uses the world’s lightest steel - to save 200g.
The seat is now shorter, lighter and 10mm lower at the rear, to aid the rider’s freedom of movement. It’s also much easier to remove and install. Maintenance is also easier, as the number of 8mm bolts securing the bodywork goes from 6 to 4 each side. The new machine is also slimmer by 70mm (50mm on the left, 20mm on the exhaust side), and the plastics thinner, while the tank cover has been removed.
Rake and trail are now tighter, 27.1°/114mm (from 27.4°/116mm), and wheelbase marginally shorter 1481mm (1482mm). Ground clearance goes up 8mm to 336mm, and the bottom yoke now sits 6.1mm higher at 928mm. The radius arc from swingarm pivot point to rear wheel spindle increases by 0.9°, to 14.5° while distance between the pivot and front spindle goes up 1.8mm to 914.6mm. Dry weight is 105.8kg, a full 2kg lighter than the previous model.
Designed with Computational Flow Dynamics (CFD) for maximum through-flow of air, the radiator shrouds are now constructed from one piece of plastic, rather than two and include a lower vent while the radiator grills are optimised for airflow. Holding 6.3L, the titanium fuel tank has also been redesigned.
Standard-fit, lightweight Renthal Fatbar flex for optimal comfort; the top yoke features two handlebar-holder locations for moving the handlebar rearward and forward by 26mm. When the holder is turned 180°, the handlebar can be moved an additional 10mm from the base position, resulting in four unique riding positions. When it comes to weight saving, small contributions accumulate (‘with enough dust, a mountain can form’ as the Japanese saying has it); with that in mind, balanced control cable wiring saves 100g.
Up front, the twin-piston brake caliper employs 30 and 27mm diameter pistons and 260mm wave-pattern disc; along with low-expansion rate brake hose it gives both a strong feel and consistent staying power. The single-piston rear caliper is matched to a 240mm wave-pattern disc.
DID aluminium rims, with directly attached spoke pattern layout are finished in black; the front is a 21 x 1.6in, the rear a 19 x 2.15in. The rear wheel is both stronger and lighter for 21YM and now Dunlop’s MX33F/MX33 soft-terrain tyres are fitted as standard equipment.
A striking new all-red graphic treatment complements the 21YM CRF450R’s sharper lines.
Saving more precious grams, the magnesium cylinder head cover has been redesigned with thinner material and the fuel pump made smaller – it secures with 4 bolts instead of 6, saves 120g and offers the same pressure and filter life as the previous design.