Bikes 31 Jul 2021

Detailed: 2022 Honda CRF250R

All-new CRF250R highlights the new year's model line-up.

Honda has unveiled its completely redesigned 2022 Honda CRF250R, with the all-new model featuring a host of changes to the engine and chassis that will bring it in line with the brand’s current premier class contender.

The goal for the 2022 CRF250R design team was ambitious and to achieve the latest racing evolution, Honda’s engineers focused their efforts on making the model quicker, stronger and lighter, by boosting engine performance, increasing toughness and cutting weight.

The redesigned engine produces more low-rpm torque without sacrificing usable top-end power, resulting in a broader powerband. Chassis updates delivered significant weight savings and improved ergonomics while preserving the model’s renowned handling prowess.

A revised exhaust system and additional lightened components resulted in a substantial reduction of four kilograms, for a 104-kilogram curb weight. In addition, durability was improved by thoroughly reexamining the engine, its cooling system and the drive components, while notable improvements were also made to the clutch.

The 249cc liquid-cooled, single-cylinder, double-overhead camshaft four-valve engine is significantly updated, boosting low rpm torque through modification of the air intake, revised valve timing and a straightened exhaust port with single exhaust header and muffler. It has a 20 percent increase in power at 6500rpm.

Changing the shape of the airbox has increased its capacity by 78 percent, primarily on the clean side of the air filter. The fuel injector’s lean angle is increased from 30 to 60 degrees, enabling the spray to reach all the way to the back of the butterfly and the throttle bore is 44mm.

These changes better cool the intake charge, improving air-intake efficiency and torque at low revs. An added benefit of the airbox redesign is improved serviceability of the air filter, with a spring-loaded clip replacing the previous threaded design.

Changes to the four-valve cylinder head are numerous. Titanium 33mm intake and 26mm exhaust valves are once again utilised, but now the intake valves feature dual springs (one inside the other) to ensure precise movement at higher revs. The intake camshaft sprocket is now press-fit, which improves valve-timing accuracy while reducing weight.

The camshaft holder has a more rigid design that maintains camshaft-journal roundness, contributing to timing accuracy and reduced friction at higher rpm. Valve action at higher revs has been further improved through redesign of the rocker-arm shaft’s alignment.

Also, durability at higher engine speeds was enhanced by revising the camshaft’s oil-supply journal, increasing flow by 80 percent. Oil volume to the cylinder head has also been increased, through a change to the ratio of the oil pump’s driven gear.

Carrying over from 2021, the bore and stroke are 79.0mm and 50.9mm, respectively, and the compression ratio is 13.9:1 To take advantage of the numerous cylinder-head improvements, the shapes of the piston and connecting rod have been modified to improve durability at high revs. Also, the water-pump gear is thicker to increase strength.

The exhaust system now utilises a single straight exhaust port, which improves torque and low-rpm drivability. The single muffler has internal baffling that is optimised for torque delivery, and it contributes to a weight reduction from the previous dual-muffler design.

The single exhaust header is now routed 74mm closer to the engine on the right side, while the left header and muffler have been eliminated, resulting in a narrower cross-section and improved rider mobility.

In order to fully realise the engine’s performance potential, the ECU provides all-new mapping to supply the optimum air/fuel mixture and ignition timing at all throttle positions and engine speeds. HRC-inspired launch control facilitates consistent holeshots.

Getting all the power to the rear wheel reliably required a redesign of the clutch assembly. The clutch pack now has nine discs instead of eight, which increases the amount of disc friction material and lowers the load on the individual discs.

The clutch basket is made more rigid for added durability, an additional friction spring reduces spring load, and lubrication is optimised to reduce wear. The primary ratio is now lower and lubrication is optimised, improving clutch endurance by 21 percent. In addition, clutch-engagement feel is enhanced and lever pull lighter.

Inside the five-speed gearbox, changes were made to reduce friction and improve feel when making up and downshifts between second and third gears – common on a 250cc motocross bike.

Only one shift fork is operated (rather than two, as before), the countershaft has improved rigidity and the shift drum is now 17 percent lighter thanks to a larger through hole and reduction of the number of lead grooves, from three to two.

The improvement results in better gear-shifting feel for the rider, and gear ratios are changed to better utilise the newfound engine power in the low and middle rpm ranges, with first and third being useable across broader speed ranges.

For Honda’s engineers, improving upon the previous CRF250R generation’s exemplary handling was a significant task, as the frame was already known for delivering reliable tracking, precise turning, exemplary straight-line stability and overall rideability.

The goals were to ensure that the engine’s newfound power would not upset these traits and to reduce the overall weight of the machine to facilitate increased manoeuvrability.

Wheelbase is now 10mm shorter (at 1477mm), rake is relaxed by 0.02 degrees (to 27.32 degrees), trail remains at 115mm, the seat height is unchanged at 961mm and ground clearance is increased by 3mm (now 333mm).

The aluminium frame is 0.68kg lighter for 2022, drawing heavily from the CRF450R. Updates include widely curved main spars with smaller cross-sections, plus optimised rib placement in the backs of the pivot plates. Longitudinal rigidity is maintained for straight-line stability, while lateral rigidity is reduced by 20 percent to enhance handling feel when cornering.

The subframe features a simplified design that enabled the elimination of a separate seat support, achieving a weight reduction of 0.31kg.

Its coil-spring Showa fork is a 49mm fully adjustable leading-axle, inverted telescopic design with 273mm of stroke. The upper and lower triple clamps have been redesigned, with rigidity rebalanced via updated reinforcement ribs, delivering increased flex for improved handling and feel through a corner.

Traction and bump-impact performance are better as well and the bike has an agile corner approach, with sharp handling characteristics. The Pro-Link rear-suspension system has a revised ratio and uses a Showa shock absorber whose shape has been adapted to work with the new frame, with adjusters moved from the left side to the right.

Rear travel is 313mm. An ultra-light steel shock spring contributes to the shock being 0.10kg lighter than last year’s component. The swingarm is also narrower, providing increased clearance in ruts, with rebalanced rigidity tuned to match the frame and improve rear traction and cornering.

Black D.I.D rims (21-inch front, 19-inch rear) deliver durable performance and good looks. Petal-style brake rotors (260mm front, 240mm rear) disperse heat. It comes with Pirelli Scorpion MX32 tyres, which are ideal for soft and intermediate terrain and which offer an appropriate amount of sidewall flex.

Rider-active design is a key feature of the 2022 CRF250R, which inherits many of the design features of the CRF450R. The right and left side panels are 20mm and 50mm more inboard, respectively, for a 70mm narrower cross section at the rear and the rear portion of the seat is 10mm lower for a flatter layout.

The radiator shroud-side panel junction is smoother as well. These user-friendly ergonomic changes permit the rider to more easily adjust body position when cornering, accelerating, jumping and braking.

The radiator shrouds are new and each is produced in a single piece instead of two separate parts. Cooling the 2022 CRF250R engine is crucial to maintaining its increased performance and overall durability.

Computational Fluid Dynamics (CFD) were used to design air-outlet vents in the shrouds and the radiator grills were redesigned, optimising the number of fins, as well as their angle. The radiators’ area of heat radiation was also increased by six percent.

Whereas the seat was previously installed by sliding it forward onto the subframe and then securing it at the rear, the new seat base has rearward-facing tongues and front-located mounting tabs. This arrangement eases installation, and acceleration forces keep the seat securely in place.

The 6.3-litre fuel tank is once again made of lightweight titanium but has a new design and the plastic tank cover has been eliminated. Engineers looked for and capitalised on every opportunity to cut weight for improved handling.

For example, only eight fasteners are used to secure all of the main bodywork components, both radiator shrouds, both side plates and the seat—instead of 12 as before. In addition, all of the bolts for the main bodywork parts now have 8mm heads, simplifying maintenance.

As before, the Renthal Fatbar handlebar is held by a clamp that can be turned 180 degrees, because the clamp itself has two mounting locations, there are four possible mounting positions for the handlebar, through a range of 26mm.

Meanwhile, the chassis borrows heavily from that of the latest-generation CRF450R, resulting in reduced weight. The redesigned frame has optimised flex characteristics, while the modern bodywork facilitates rider movement and is more easily removed.

The 2022 Honda CRF250R is set to hit showroom floors in September at a retail price of $12,199. Visit motorcycles.honda.com.au for additional information on the entire range.

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