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Honda Announces Revised CRF250R and CRF450R for ’05



2005 Honda CRF450R

Honda has released pictures and specs for the 2005 CRF four-stroke MX bikes, revealing the updates made to the bikes for the new model year.

The biggest news is the CRF450R’s all new, 4th-gen aluminum frame, similar to the 4th-gen design first seen on the CRF250R when it was released last year. Both bikes also receive a series of minor changes, most designed to shave weight (the CRF250R loses 2 pounds, while the 450 drops 3.5).

The CRF250R also receives some significant engine modifications aimed at increasing low-end power.

Here is the official Honda info regarding the 2005 CRF450R:

Torrance, Calif. 06/01/2004 — Honda’s race-proven superstar, the CRF450R enters 2005 with a wealth of refinements
and a lighter weight that make this big four-stroke the overwhelming class favorite.

Features & Benefits

New for 2005

• New fourth-generation twin-spar aluminum frame. Forged aluminum steering
head and tapered downtube section are designed to optimize frame rigidity. In
addition, tall swingarm pivot plates and thin frame spars create a narrow overall
frame cross-section for superb rider comfort and maneuverability.
• Semi-double-cradle frame design features a single, large-diameter tapered
downtube. Two rugged box-section rails attach to the base of the downtube and
support the engine. A forged aluminum steering head provides a compact and extremely
durable mount for the frame spars and engine downtube.
• New swingarm features a dual-axis, double-taper design with a large
cast aluminum cross-member that is lighter weight and stronger.
• New shift drum, shift forks and shift fork shafts for more precise shifting.
• New front and rear suspension valving for improved bump absorption.
• New front axle placement for improved fork action and turning.
• New Pro-Link(r) ratio combined with 5.5 kg rear shock spring for more
compliant suspension action.
• New exhaust pipe heat shield made from titanium for weight savings.
• New airbox and intake tube for more direct airflow and increased power.
• New side number plate with built-in airbox vents for improved air flow.
• New aluminum clutch cable bracket for lighter weight.
• New rear hub is stronger and lighter.
• New one-piece seat bolt for easier maintenance.
• New lighter rear brake pedal.
• New rear brake pad insulators for consistent braking action.
• New narrower radiators for improved rider ergonomics while maintaining
cooling capacity.
• New radiator hose routing for lighter weight and improved cooling.
• Overall weight reduced by 3.5 pounds.

Engine/Drivetrain

• Powerful engine churns out 55 bhp at 9000 rpm and 36.9 lb./ft. of torque
at 6500 rpm. Power is produced across a wide rpm-band for easy-to-control operation.

• Auto decompression and hot restart system make starting easy in all
conditions.
• Liquid-cooled four-valve Unicam(tm) 449cc engine produces more than
120 hp per liter while maintaining Honda’s legendary dependability and simplicity.
• Compact, lightweight engine assembly weighs only 63.8 pounds.
• ACG cover made from magnesium for reduced heat build-up and lighter
weight.
• Unicam valve train provides the light weight of a compact single-cam
drive and the optimum combustion chamber shape for maximum power at all engine
rpm.
• Unicam valve train features a carburized single camshaft that directly
actuates two 36mm titanium intake valves. The camshaft exhaust lobe actuates
two 31mm steel exhaust valves via a forked, low-friction roller rocker-arm.
A separate cam holder contributes to the compact design, which allows a remarkable
21.5° included valve angle and saves 13.3 ounces over a comparable DOHC
system.
• Lightweight titanium intake valves permit use of smaller valve springs,
reducing overall engine height and saving 15.2 grams per valve compared to a
steel valve design.
• Unique, internal pin-rotation-type auto decompressor produces a lightweight,
compact system that provides superb cold-starting and hot-restarting operation.
• Crankshaft is made of high-strength, low-carbon steel with carburized
main journals for maximum durability at sustained high-rpm operation.
• Forged 12.0:1 compression slipper piston is more than 4.5 ounces lighter
than a conventional design, revving quickly while maintaining excellent cylinder
sealing and high-rpm power.
• Double-carburized connecting rod utilizes a big-end needle bearing for
maximum high-rpm performance and durability.
• Nikasil(r) cylinder lining is lightweight and provides cooler and quieter
operation for extended engine life.
• Press-fitted aluminum spark plug pipe fits between forked exhaust rocker
arms, further contributing to compact cylinder head design.
• 40mm FCR-type carburetor features four rollers on the flat slide, resulting
in very light throttle effort, smooth operation, crisp throttle response and
excellent ride-ability. Bottom of float chamber is designed to allow more fuel
to pass to the main jet.
• An 8-bit digital CPU incorporates the capacitive discharge ignition
(CDI), producing immediate data calculation and extremely accurate ignition
for maximum performance.
• Twin-sump lubrication system separates the oil supply for the crankshaft,
piston and valve train from the clutch and transmission. This ensures a cool
supply of oil to the clutch, eliminates clutch and transmission material contamination
to the engine oil, and reduces the amount of circulating oil and the required
size of the oil pump.
• Vertically split crankcases feature a built-in oil pump, reducing weight
5.1 ounces compared to a conventional design.
• Exhaust system uses a lightweight titanium exhaust header, stainless
steel pipe and re-packable aluminum silencer with aluminum end cap.
• Long-lasting silencer packing.
• Dual radiators provide significantly more surface area and more effective
heat dissipation compared to a single-radiator design.
• Gear-driven balancer reduces vibration and drives the water pump. Eight
clutch plates provide the surface area necessary to handle the engine’s massive
torque, while carefully matched clutch springs provide a light feel at the lever.

Chassis/Suspension

• The aluminum frame design is matched to rider ergonomics to maximize
handling and control operation.
• Front and rear wheels feature HRC(r) works-type lightweight aluminum
spoke nipples.
• Front wheel features large-diameter front axle and wide wheel-bearing
span for excellent rigidity.
• Rear axle diameter of 25mm and large-diameter bearings provide significant
rigidity to withstand torturous track conditions.
• Lightweight, 47mm inverted Showa(r) twin-chamber cartridge fork with
aluminum dampers feature settings unique to the CRF(tm). The fork offers 12.4
inches of travel, 16-position rebound and 16-position compression damping adjustability.
Front fork stanchions’ inner surfaces use same honing process as on works bikes
for reduced friction.
• Pro-Link single-shock rear suspension system features a fully adjustable
Showa rear damper and 12.5 inches of wheel travel, separate low-speed (13 positions)
and high-speed (3.5 turns) compression damping adjusters and 17-position rebound
damping adjustability.
• Rear shock’s damper piston diameter is 50mm for consistent performance
under demanding riding conditions.
• Compact dual-piston front brake caliper has been designed for a weight
savings of more than 1 ounce. Anodized aluminum brake pistons and lightweight
front brake disc minimize unsprung weight for improved turning and handling.
• HRC works-type rear brake system integrates the rear master cylinder
and fluid reservoir, eliminating the rear master cylinder reservoir and hose.

• Large, 240mm front and rear brake discs.

Additional Features

• Frame design allows sidecovers to have larger air-intake ducts, contributing
to significant airflow increase in the mid- and upper-rpm ranges.
• Rider ergonomics are optimized by adapting the handlebar, seat and footpeg
height to place the rider’s legs at the narrowest cross-section of the frame,
for improved comfort and handling feel.
• Seat cushion follows the shape of the fuel tank, providing a smooth
transition to increase rider mobility and comfort.
• Non-slip seat cover for increased rider-control.
• Brake pedal and shift lever are designed to complement the riding position.

• Brake pedal features optimized ratio to match integrated rear-brake
master cylinder design.
• Wide, cleated stainless steel footpegs are self-cleaning, corrosion
resistance, provide excellent grip and fold for extra ground clearance.
• Rear brake pedal and shift lever are made of lightweight aluminum.
• Adjustable front brake lever for maximum control.
• Quick-adjust clutch perch for easy cable adjustment.
• Aluminum 971 bend Renthal handlebars as standard equipment is rubber-mounted
to reduce rider fatigue and improve comfort.
• CR handlebar holders provide three different mounting positions: standard
CRF450R holder provides +/- 3mm fore or aft position to match rider preference,
and optional holder (CR(r)250R-type) provides neutral position.
• Works-type handlebar grips add to rider comfort.
• Dunlop 742 front and 756 rear tires for improved traction and cornering.
• Front disc brake cover helps protect rotor and caliper from damage.
• Removable rear subframe allows easy maintenance.
• Washable, two-stage foam air filter for optimal engine protection and
easy maintenance.
• Repackable silencer for maximum performance and minimal noise.
• Comfortable, durable controls and high-quality fasteners.
• Stainless steel clutch cable for long life.
• Honda Racing-inspired colors and graphics.
• Ownership includes one-year complimentary membership in the Honda Rider’s
Club of America(tm) (HRCA(r)). Benefits include: discounts, travel benefits,
roadside assistance for off-road bike transport vehicle while motorcycle is
being transported, one year complimentary subscription to Honda Red Rider(tm)
magazine, access to HRCA Clubhouse Web site (www.hrca.honda.com), access online
to Honda Common Service Manual. For HRCA details, call 1-800-847-HRCA.

And now, Honda’s press release on the CRF250R:

Torrance, Calif. 06/01/2004 — Racing improves the breed, which means this class-leading front runner enters
2005 with a host of new features plus a lighter weight.

Features & Benefits

New for 2005

• New cylinder head porting for increased power at lower rpm.
• New camshaft profile increases low-rpm torque while maintaining maximum
horsepower.
• New ignition map works in conjunction with new cylinder head and camshaft
for improved power at virtually all engine speeds.
• New spark plug with side electrode for improved spark and complete combustion.

• New aluminum spark plug tube for lighter weight.
• New lightweight right engine cover for improved transmission and clutch
lubrication.
• New stiffer clutch springs for improved feel and increased durability.
• New shift drum, shift forks and shift fork shafts for more precise shifting.
• New rear hub is lighter and stronger.
• New swingarm construction for lighter weight.
• New exhaust pipe for lighter weight and mass centralization.
• New muffler design for lighter weight and mass centralization.
• New rear brake pad insulators for consistent braking action.
• New fork and rear suspension valving for improved bump absorption.
• New front axle placement for improved fork action and turning.
• New improved Pro-Link(r) ratio.
• Overall bike lighter by 2.0 pounds.

Engine/Drivetrain

• Powerful four-stroke 249cc liquid-cooled four-valve Unicam(tm) engine
is designed to produce power across a wide rpm range for easy-to-control operation.

• Lightweight, compact, internal auto decompression and handlebar-mounted
hot-start system provide superb operation, hot or cold.
• Compact, lightweight engine assembly weighs only 52.7 pounds.
• Unicam valve train provides the light weight of a compact single-cam
drive and the optimum combustion chamber shape for maximum power at all engine
rpm.
• Unicam valve train features a carburized single camshaft that directly
actuates two 31mm titanium intake valves. The camshaft exhaust lobe actuates
two 26mm steel exhaust valves via a forked, low-friction roller rocker-arm.
• Lightweight titanium intake valves permit use of smaller valve springs,
reducing overall engine height.
• Crankshaft is made of high-strength, low-carbon steel with carburized
main journals for maximum durability at sustained high-rpm operation.
• ACG cover, clutch cover and cylinder head cover are made of magnesium
to reduce engine weight.
• Forged 12.9:1 compression slipper piston and rings are lighter than
a conventional design, revving quickly while maintaining excellent cylinder
sealing and high-rpm power.
• Double-carburized connecting rod utilizes a big-end needle bearing for
maximum high-rpm performance and durability.
• Nikasil(r) cylinder lining is lightweight and provides cooler operation
for extended engine life.
• Press-fitted aluminum spark plug pipe fits between forked exhaust rocker
arms, further contributing to compact cylinder head design.
• 37mm Keihin FCR carburetor features four rollers on the flat slide,
resulting in very light throttle effort, smooth operation, crisp throttle response
and excellent rideability.
• Carburetor features a throttle position sensor (TPS) that helps maintain
a linear throttle response throughout the range.
• Twin-sump lubrication system separates the oil supply for the crankshaft,
piston and valve train from the clutch and transmission. This ensures a cool
supply of oil to the clutch, eliminates clutch and transmission material contamination
to the engine oil, reduces the amount of circulating oil, and permits the use
of a smaller oil pump.
• Vertically split crankcases feature a built-in oil pump, reducing weight
compared to a conventional design.
• Exhaust system uses a lightweight stainless exhaust header and repackable
aluminum muffler.
• Dual radiators feature a refined core area for improved heat dissipation
compared to conventional dual-radiator design.
• Gear-driven balancer reduces vibration and drives the water pump. Eight
clutch disks provide the surface area necessary to handle the engine’s impressive
torque, while carefully matched clutch springs provide a light feel at the lever.
• Durable five-speed close-ratio transmission.

Chassis/Suspension

• Fourth-generation twin-spar aluminum frame is derived from Honda’s
CR(r) series. Forged aluminum steering head and tapered downtube section are
designed to optimize frame rigidity. In addition, tall swingarm pivot plates
and thin frame spars create a narrow overall frame cross-section for superb
rider comfort and maneuverability.
• Frame design features a single, large-diameter tapered downtube. Two
rugged box-section rails attach to the base of the downtube and support the
engine. A forged aluminum steering head provides a compact and extremely durable
mount for the frame spars and engine downtube.
• The aluminum frame design is matched to rider ergonomics to maximize
handling and control operation.
• Swingarm features a dual-axis, double-taper design with a large cast
aluminum cross-member.
• Front and rear wheels feature HRC(r) works-type lightweight aluminum
spoke nipples.
• Front wheel features large-diameter front axle and wide wheel-bearing
span for excellent rigidity.
• Rear axle diameter of 25mm and large-diameter bearings provide significant
rigidity to withstand torturous track conditions.
• Lightweight, 47mm inverted Showa(r) twin-chamber cartridge fork with
aluminum dampers. The fork offers 12.4 inches of travel, 16-position rebound
and 16-position compression damping adjustability. The inner surface of the
front fork outer-tubes receives same honing treatment as works bikes for low-friction
operation.
• Pro-Link single-shock rear suspension system features a fully adjustable
Showa rear damper and 12.4 inches of wheel travel, separate low-speed (13 positions)
and high-speed (3.5 turns) compression damping adjusters and 17-position rebound
damping.
• Rear shock damper piston diameter is 50mm for consistent performance
under demanding riding conditions.
• Compact twin-piston front brake caliper, anodized aluminum brake pistons
and lightweight front brake disc minimize unsprung weight for improved turning
and handling.
• HRC works-type rear brake system integrates the rear master cylinder
and fluid reservoir, eliminating the rear master cylinder reservoir and hose.

• Large, 240mm front and rear brake discs.

Additional Features

• All plastic body components (radiator shroud, sidecovers, rear fender,
seat base, fuel tank, front fender and front number plate), offer a slim, aggressive
style and light weight.
• Frame design allows airbox sidecovers to have larger intake ducts, contributing
to significant airflow in the mid- and upper-rpm ranges.
• Rider ergonomics are optimized by adapting the handlebar, seat and footpeg
height to place the rider’s legs at the narrowest cross-section of the frame
for improved comfort and handling feel.
• Seat cushion uses foam construction that follows the shape of the fuel
tank, providing a smooth transition to increase rider mobility and comfort.
• “Non-slip” seat cover for increased rider control.
• Cleated rear brake pedal and folding shift lever are made of lightweight
aluminum and are designed to complement the riding position. Brake pedal features
optimized ratio to match integrated rear-brake master cylinder design.
• Wide, cleated stainless steel footpegs are self-cleaning, resist corrosion,
provide excellent grip and fold for extra ground clearance.
• Aluminum Renthal handlebar (971 bend) is rubber-mounted to reduce rider
fatigue and improve comfort.
• CR handlebar holders provide three different mounting positions: standard
CRF250R holder (CRF450/CR125R-type) provides +/- 3mm fore or aft position to
match rider preference, and optional holder (CR250R-type) provides neutral position.
• Works-type handlebar grips add to rider comfort.
• Adjustable front brake lever.
• Quick-adjust clutch perch for easy cable adjustment.
• Clutch lever designed to improve feel and action.
• Dunlop D742 front and D756 rear tires are fitted for maximum traction
and cornering performance.
• Chain guide material offers improved wear resistance, with a service
life five times greater than conventional materials.
• Front disc brake cover helps protect rotor and caliper from damage.
• Removable rear subframe allows easy maintenance.
• Washable, two-stage foam air filter for optimal engine protection and
easy maintenance.
• Repackable silencer for maximum performance and minimal noise.
• Comfortable, durable controls and high-quality fasteners.
• Stainless steel clutch cable for long life.
• Honda Racing-inspired colors and graphics.
• Ownership includes one-year complimentary membership in the Honda Rider’s
Club of America(tm) (HRCA(r)). Benefits include: discounts, travel benefits,
roadside assistance for off-road bike transport vehicle while motorcycle is
being transported, one year complimentary subscription to Honda Red Rider(tm)
magazine, access to HRCA Clubhouse Web site (www.hrca.honda.com), access online
to Honda Common Service Manual. For HRCA details, call 1-800-847-HRCA.