The All New 2013 Honda CRF450R

Big news: Honda has an all-new 450-motocross machine and Dirt Rider just got to ride the thing! As you can see, the engine and the lower cradle of the frame are about the only things left that resemble the old 2012 Honda CRF450R; the new look is sleek and the twin mufflers grab your attention immediately. We spent a few hours on the new steed up at Zaca Station motocross track but before we tell you our first impression, here is the laundry list of what is new:

All new styling, all new frame, all new swing arm, all new KYB air forks and just all around all new. It now also has two mufflers!
The new Honda is aggressive and the rear fender now has a lift point with integrated support to make it easier to hoist the bike onto a stand. Fuel capacity has bumped from 1.50 to 1.66 gallons. The footpegs are now 10 percent lighter and the new design allows for better clearing in muddy conditions.
This will be the most changed 450cc motocross machine for 2013 and the price is the same as it was in 2012.
The only part on the frame that resembles the 2012 is the lower cradle. The head tube area is radically different and the subframe is all-new to accommodate the twin mufflers.

CHASSIS

The all-new aluminum frame is quite different and just looking at the junction of the steering head shows how the main frame spars intersect distinctly lower on the steering head pipe, much closer to the midway point rather than toward the top as per the previous design. The new frame was designed to incorporate a new two-muffler exhaust system that tucks in tightly toward the bike’s center to better centralize mass and lower the moment of inertia. A new aluminum swingarm goes with the new frame and provides added rigidity thanks to taller beam height in the front and center sections for less deflection in ruts and improved corner-exit traction. Also, with the change to dual mufflers, the aluminum subframe is now lighter and shorter than before.

The mufflers aren’t round, they have a distinct shape and while Honda wouldn’t tell us what was inside, we’d guess it is more than just packing.

Not only did the Honda get a new frame, it now uses 48mm KYB Pneumatic Spring Forks (PSF), which use air pressure to provide spring resistance in place of steel springs. The new KYB fork is not only 1.76 pounds lighter, there is more room for a new and larger piston in the cartridge damper—32mm in diameter rather than 24mm in the previous fork. Because of this the front suspension system offers more tuning potential. The forks are equipped with Schrader valves atop the fork caps, and standard air pressure of 33 psi can be adjusted within a range from 32 psi to 36 psi—the equivalent of installing softer or stiffer replacement springs. This is key to accommodating varying rider weights and speeds. Air alone fulfills the pressurization needs; there’s no need for nitrogen or other inert gasses. The rear Pro-Link system now features a new shock that’s 14.5mm shorter than before, and it sits lower in the frame to help lower the center of gravity.

The fork on the left has a spring, the fork on the right is the new KYB air fork, no springs in sight. A simple hand pump is all that is needed to make changes to the fork and how the bike handles.
While you aren’t going to fit your average bicycle pump on the Schrader valve, the common pumps used on mountain bike suspension work great and are easy to use.

ENGINE

The 2013 Honda CRF450R follows previous engine architecture, but changes increase power, especially in the low-end and midrange, while also adding durability. A new camshaft with different valve timing and more valve overlap, larger exhaust valves (30mm diameter to 31mm), a new piston with a fuller dome to increase compression ratio from 12.0: to 12.5:1, new port shapes on the intake and exhaust sides for enhanced flow, and revised settings for the PGM-FI fuel injection system comprise the major performance upgrades.

Gone is the four-spring clutch and back is a six spring, improving durability and feel.

For added durability, the piston skirt is now shot-peened with molybdenum disulfide to create a tougher, low-friction surface. A redesigned oil jet now gives two sources to spray cooling oil on the underside of the piston, and the transmission is a completely new, heavy-duty gearbox with wider gears. The clutch is now a six-spring design for stronger clamping pressure with a lighter clutch feel, better modulation of the friction point and added durability. To help provide smooth power delivery Honda went with a slightly heavier flywheel that increases rotational inertia by 11 percent compared to the prior generation.

On the intake side of the engine, a new airbox and straighter airboot inlet shape improve airflow; the new airbox also makes it easier to service the air filter. The use of two mufflers allows a greater flow for more power without more noise. Also, the decision to install two mufflers allows each muffler to be shorter, and therefore closer to the bike’s center of mass. The two mufflers together weigh only slightly more than a comparable single, larger muffler but having the two mufflers tucked in tighter results in a lighter more flickable feel. The dual-muffler design allows the CRF450R to easily meet more stringent sound requirements enacted by various race-sanctioning organizations.

Other little changes include a new front disc cover that can easily be removed without taking off the front wheel and a Dunlop MX51FA front tire that is a special version just for the Honda CRF450R. The all-new radiators are mounted lower in the chassis for that continuing quest to lower the center of gravity.

The power is smooth and the handling solid. The new bike is an improvement over the 2012 model.

WARM AND FUZZY

We only rode the new 2013 Honda CRF450R for a few hours but we left Zaca with a good feeling and liking the bike. The new mods are aggressive and the overall, the bike performed well. The powerplant changes resulted in an ultra smooth power delivery off idle and the power goes straight to the ground in a fun controllable manner all the way to the rev limiter. In situations we had to cover the squishy clutch on the 2012 model, we could ignore the lever on the 2013 and simply roll on the gas without a worry of flame out or an uncontrollable slide out. The new KYB air forks have us excited and ready to constantly change the pressure to find the perfect handling. So far are stoked on the feel of the fork and how it worked over small bumps and it handled big hits with ease. The front of the bike felt very planted without any wandering or vagueness, tracking through corners nicely. We've seen twin pipes before but these are short, low and keep the power of the bike strong while staying within sound requirements. Stayed tuned to Dirt Rider Magazine for the full test when we get one to keep!

It will take some time to get used the sight of two mufflers, again. Honda ran twin pipes on the CRF250F in 2005 but a few years later went back to the single muffler.

2013 CRF450R SPECIFICATIONS

Engine Type: 449cc liquid-cooled single-cylinder four-stroke

Bore and Stroke: 96mm x 62.1mm

Compression ratio: 12.5:1

Valve Train: Unicam, four-valve; 36mm intake, titanium; 31mm exhaust, steel

Induction: PGM-FI, 46mm throttle body

Ignition: Full transistor with electronic advance

Transmission: Close-ratio five-speed

Final Drive: #520 chain; 13T/48T

Suspension

Front: 48mm inverted KYB PSF® (Pneumatic Spring Fork) with rebound and compression-damping adjustability. 12.2 inches travel.

Rear: Pro-Link KYB single shock with spring preload, rebound damping adjustability, and compression damping adjustment separated into low-speed and high-speed; 12.5 inches travel

Brakes

Front: Single 240mm disc with twin-piston caliper

Rear: Single 240mm disc

Tires

Front: Dunlop MX51FA 80/100-21

Rear: Dunlop MX51 120/80-19

Wheelbase: 58.7 inches

Rake (Caster Angle): 27° 04’

Trail: 116mm (4.57 inches)

Seat Height: 37.5 inches

Ground Clearance: 13.0 inches

Fuel Capacity: 1.66 gallons

Color: Red

Honda claimed curb weight: 242.7 pounds