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® ratio.
• Overall bike lighter by 2.0 pounds.
Engine/Drivetrain
• Powerful four-stroke 249cc liquid-cooled four-valve Unicam™ 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® 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® 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® 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® 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™ (HRCA®). 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™ 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.