Honda’s new CRF450L a complete package
Using the CRF450R moto-crosser as a base, Honda’s new road-legal dual-purpose motorcycle has a tough, lightweight chassis built to find all the available grip, powered by an engine that delivers strong, usable power right from the bottom.
31 May 2018 | Motors
The CRF450L is about having maximum fun out on the dirt. - M. Uchiyama, Large Project Leader: 19YM CRF450L.
All the attributes that make it great fun off-road also enable it to be really useful around town; narrow and nimble, a dual-purpose machine slips through gaps, soaks up the hits from rough roads and stays well ahead of traffic thanks to smart, low-gear acceleration. It also needs to be turn-key reliable, with sensible intervals between major service work.
Competition machines can make a solid base for dual-purpose adaptation. But there is much to consider. Race-level performance brings with it an intensive maintenance schedule, which is simply too much for many ‘hobby’ trail riders, who just want to push a button and go – and keep on going, Furthermore, a barely-disguised race bike can mean crucial road-going elements - lights, indicators, ignition switch - are not as user-friendly and durable as they should be.
Honda understands this, and with a desire to produce a dual-purpose bike that draws strongly on the fundamental performance of a race machine, yet with much more ‘normal’ service intervals and high-quality road ancillaries, has taken its CRF450R moto-crosser as the base to start from, and created the new CRF450L.
It is unmistakably a race-bred CRF – and looks it – but with the additions and modifications needed to make it both road legal and supremely useable in a trail environment. As such, the CRF450L is a complete package, as happy roosting trails as it is linking them up on-road. And with Honda engineering and build quality at its core, is sure to do so for years to come.
“The CRF450L is about having maximum fun out on the dirt. It looks like a CRF450R because, really, it is – just a trail-friendly, road-legal version. That’s what the ‘L’ stands for – ‘legal’. It’s been engineered to deliver excellent handling feel, with linear engine torque that helps the rider make the most of the available grip in all conditions. And, it contains its HRC-derived CRF technology within a real-world service schedule,”says M. Uchiyama, Large Project Leader (LPL) 19YM CRF450L.
The journey from full race to road legal trail was a detailed one for the CRF450L.
Road legality required the engine to gain EURO4 compliance, while from a longevity and usability viewpoint, the power output and character, needed careful attention.
It’s still a CRF450R; just one that’s quieter, both mechanically from the chassis and engine, as well as its new exhaust. Both fuelling and ignition maps are now managed by 02 lambda sensor; compression ratio has been lowered and crank mass increased for improved drivability. The gearbox is a 6-speed – for longer legs on the road – and a cush drive has been added to the 18-inch rear wheel.
The plastics are lifted directly from the CRF450R and all lighting is LED, with the front headlight in particular throwing out a penetrating beam. Increased volume for the titanium fuel tank adds range and all the items that make the CRF450L ready to purchase as a licensed, road going machine – such as speedometer and horn – are present as standard.
While the chassis was more straightforward to convert from its CRF450R moto-crosser specification to a dual-purpose performance level, the 449cc engine needed more consideration from Honda’s engineers. Requirements were several: the need for it to pass EURO4 emissions and noise regulations, and to be usable for a wide variety of riders in many differing situations both on and off-road.
While the fundamental architecture of the four-valve Unicam powerplant remains the same, many details have been changed to support the broader role: the crank’s mass has been increased, resulting in 13% more inertia which, for a trail rider, equals improved torque feel and response; valve timing has been revised to give the broader, smoother spread of power and torque; the gearbox is now 6-speed, rather than 5 for longer range use on tarmac; left and right engine covers wear outer covers to reduce noise;
Elsewhere, the ACG has been uprated, to provide the required electrical power for the LED lights and to maintain battery charge during lower-speed running. The battery itself is a high-volume unit.
Bore and stroke are unchanged from the CRF450R, at 96mm x 62.1mm, but the piston uses 3 rings instead of 2 for greater durability. Compression ratio is 12.0:1 (compared 13.5:1). The redesigned airbox feeds the PGM-FI, managed by a lambda sensor in the large-volume single exhaust (which replaces the ‘stubby’ dual-pipe design of the CRF450R). An Air Injection (AI) system and catalyser clean up the spent gases.
The four-valve Unicam cylinder head features a finger rocker arm on the inlet valves; valve lift is 7.7mm with 6.7mm exhaust valve lift. Inlet valve diameter is 38mm. The valve springs are oval in cross section and valve angle is 9° intake/10.5° exhaust.
The clutch spins 7 friction discs with a 2mm clutch plate efficiently dissipating heat; the springs generate a good, consistent connection. The front sprocket is a 13T, the rear 51T.
Peak power is 18.4kW, with peak torque of 32Nm. Important from the hobby trail-rider’s perspective is the engine’s reliability and gap between service intervals. And this is where the CRF450L’s build quality and design really stands out; it will go 32 000km between major strip downs, with an air filter oil and oil filter change every 1000km. - QuickPic