2013 Honda CRF450R

We’ve seen James Stewart throw some of the biggest scrubs of all time in the last few years, some landing him on his head, others resulting in amazing photos or videos. These photos and videos have spread like wildfire via social media and now every rider thinks it’s time to scrub every bump and jump on the track. Obviously this tricky technique – lying the bike flat over a jump to scrub off height in order to maximise overall pace – is effective, otherwise Stewart wouldn’t be known as ‘The Fastest Man on Earth’. Whether you agree with that tag or not, it was about time somebody built a bike that made 'TheBubba Scrub' easy.

Hands down, the Honda CRF450R has been the best handling bike on the market for some time now. Its only drawback – and the only aspect preventing from leading the class – was that it was a little lacking in power. For the 2013 model, however, Honda has collaborated with multi AMA supercross champion Jeremy McGrath, utilising his knowledge and expertise to build a bike with even better handling, yet appreciably more power.

With a new frame that weighs just 9.35kg, improved mass centralisation (the weight is now lower and further forward), a new and more rigid swingarm and a KYB air fork, the 2013 CRF450R is built to scrub. Add to that a revised engine with more low-to-midrange punch and a twin exhaust set-up and you have one stylish, potent motocross weapon ready to appease the most demanding of scrub and whip fiends.

After hearing all the hype about the bike coming out of America, I was keen to get my leg over one and give it a run. To tell the truth, the Honda was released quite early in America and so I was left daydreaming for some months over here in Oz. But I made up for lost time, taking it for a spin at Lakes Motocross Track on the NSW Central Coast one weekend, before returning a week later to race it.

ENGINE
In order to boost low to mid-range power without sacrificing top-end punch, Honda affected a range of updates. The compression ratio was raised from 12.0:1 to 12.5:1 with the help of a new shot-peened, moly-coated piston, which is said to reduce friction while increasing strength. The exhaust valve diameter was increased from 30mm to 31mm, while the inlet port was reshaped to improve gas flow. The valve timing was massaged to increase valve overlap, too, which Honda says helps to improve power all the way through to the mid-range. A new airbox and air filter element ensures efficient filtration and maintains internal pressure when the throttle is opened hard, while revised fuel injection settings are said to allow the other engine updates to achieve their full potential.

The clutch has been upgraded to a six-spring design for added clamping force – Honda says it also delivers a longer clutch life and less slippage – while the new five-speed close-ratio gearbox has been strengthened. Honda says all the changes have resulted in a more powerful engine (although the manufacturer doesn’t go so far as to quote power and torque stats), in what is still a relatively gentle and easy-to-ride package, with a broad, smooth and rider-friendly power curve.

With the added bottom-end power you can short-shift the gears to keep the bike in the torquey part of the rev range. I prefer to ride lower in the rev range rather than valve bouncing the engine, so I loved the fact that extra power was there to call on if I needed it. Having said that, the engine makes power all the way to its rev limiter, although I never felt the need to rev it that far to get things moving.

If I hadn’t raced the CRF I would have said it had a very flat power curve, but after racing it I realised this in fact isn’t the case. The twin pipes are extremely quiet, which gives you the feeling that the bike doesn’t bark. When you’re racing around the track you can easily hear the other bikes around you over the top of the Honda, so I was mistaken into thinking the Honda didn’t have a whole lot of torque. But when I took off for my first start I realised the CRF actually does launch and take off – it just doesn’t make a whole lot of noise while it’s doing it.

What I love most about the CRF’s engine is its smoothness. You can grab a fistful of throttle early in the turn and know it won’t spit you off the track. For a 450 it’s a very user-friendly engine. The gearbox feels comfortable and shifted with ease. I think the gearing could do with an extra tooth on the back because I wasn’t reaching top gear on some of the long hills, and the bike would also bog a little in some of the soft, loamy corners if I wasn’t in the right gear.

The clutch is responsive but you had to be careful not to overheat it. I had to click the bike into gear right before the 30-second board turned or the clutch would heat up and I’d lose my lever -- the bike would want to go before I’d even let the clutch out. It didn’t seem to be a problem once I was on the track; maybe a different oil grade would address the issue.

CHASSIS
When I first heard the Americans say this new bike is built for scrubbing I thought it was nothing more than a sales pitch, but it’s not until you ride the new CRF450R that you realise they weren’t kidding. The new, next-generation aluminium frame is said to improve mass centralisation by situating the weight lower and further forward in the frame, and I have no reason to doubt that claim. The frame’s lower front tube section and 14mm lower rear shock mount, together with the KYB air fork (1kg lighter than the fork on the previous model) and new swingarm make the Honda more nimble and agile, with improved traction front and rear. Honda says it’s the lightest bike in its class, too, which sure doesn’t hurt out on the track.

New footpegs are said to be 10 per cent lighter and they’re mounted 5mm further back to better centralise the rider’s body weight, while the all-new bodywork adds to the aggressive styling while aiding rider manoeuvrability.

Riding the CRF450R is effortless -- this bike can make even the unfittest of riders look like a rockstar. I found I could change direction with ease while the front wheel stuck like glue, even to the slickest of hard-pack surfaces. It doesn’t even really feel like a 450. It’s got all the power of a 450, but it’s so nimble and light to ride you could be forgiven for thinking you’re on a smaller-capacity machine. The rear of the bike around the exhausts feels a little bulkier than normal but I quickly got used to it. The stylish plastics and tank shrouds make gripping the bike with your knees easy and moving around on top of the bike poses no problems.

The suspension is a little soft from standard so I opted for pumping the fork up to 42psi to keep the front sitting high. Then I took the compression adjustors out four clicks from hard and screwed in the rebound adjustors a few clicks from standard – this effectively controlled the hammering from the higher air pressure in the fork, especially once the track got rough. I could easily attack the largest bumps on the track and the bike would stay balanced and skip over the top without stepping sideways. Carrying speed into corners was also easy, as I had so much confidence in the front wheel. I knew I could push it hard and it would stay put.

Jumping the CRF is the easiest part of all. The bike feels very light and manoeuvrable in the air. It just inspires confidence – after just a few minutes getting used to the bike it has you scrubbing and throwing whips with abandon. The brakes are also on the money, pulling me up whenever I called on them without a problem. I like a lot of feel in my front brake lever so I removed the nut on the front brake adjuster and replaced it with a washer to take out all the free play at the lever. Once I’d done that I had all the confidence in the brakes I needed.

The KYB air fork truly is the next big step for motocross bikes. You no longer have to spend big bucks on getting your suspension set up – all you need is a bicycle pump and a little knowledge and you can tune them yourself. The hardcore racer will still benefit from installing specific valving to suit their weight and riding style, but being able to adjust the fork’s air pressure as a track gets progressively chopped out is a big plus.

The new frame design and the lowering the bike’s centre of gravity has had a real effect on the bike’s handling. The CRF450R isn’t necessarily a whole lot lighter than anything else on the track, but it sure feels it to ride. Honda has really hit its mark with this bike. It lives up to every claim and then some.

Visit the 2013 CRF450R in Bike Showroom

SPECS: 2013 HONDA CRF450R
ENGINE
Type: Liquid-cooled, four-stroke single-cylinder
Capacity: 449cc
Bore x stroke: 96mm x 62.1mm
Compression ratio: 12.5:1
Fuel system: Electronic fuel injection

PERFORMANCE
Claimed maximum power: N/A
Claimed maximum torque: N/A

TRANSMISSION
Type: Five-speed, close ratio
Final drive: 520 chain, 13T/48T

CHASSIS AND RUNNING GEAR
Frame type: Aluminium
Front suspension: 48mm inverted KYB PSF (Pneumatic Spring Fork) with rebound and compression damping adjustment, 310mm of travel
Rear suspension: Pro Link KYB monoshock with adjustable spring preload and rebound damping, plus high/low-speed compression damping adjustment, 315mm of travel
Front brake: Single 240mm disc with twin-piston caliper
Rear brake: Single 240mm disc with single-piston caliper
Tyres: Dunlop MX51, 80/100-21 front and 120/80-19 rear

DIMENSIONS AND CAPACITIES
Rake: 27 degrees
Trail: 116mm
Claimed wet weight: 110kg
Seat height: 952mm
Wheelbase: 1491mm
Ground clearance: 330mm
Fuel capacity: 6.3 litres

OTHER STUFF
Price: $11,670
Colour: Red
Testbike supplied by: Honda Australia, www.hondamotorcycles.com.au