TWMX First Impression: 2005 Honda CR250R

By Mitchell Bailey

Yesterday, TransWorld Motocross took delivery of its 2005 Honda CR250R test bike at Racetown 395 in Adelanto, California. Officially the last 250cc two-stroke to hit dealership floors this new-bike season, the CR250R has been touted by Honda as a vastly improved machine…

The main focus for 2005 was improving the CR250R’s case-reed motor, and everything “from the airbox to the tip of the exhaust system was changed to improve airflow, so that the new CR would have better low-end and mid-range power. Instead of focusing so much on the changes, however, we’ll get right into our riding impressions of the new machine. You can find a full rundown of all the improvements and specifications a little further down the page…

For our initial test session on the bike, American Honda brought the TWMX crew out to Racetown 395 in Adelanto, California. The high-desert facility was in rough shape and appeared to have not been completely groomed since the Vet X race held there a couple weeks earlier. Though some sections of the track were dragged deep and loamy, others were riddled with rock-hard ruts and rim-bending potholes. That said, it was a perfect place to test out all aspects of the new CR’s personality!

Lots of hype has been made about the new motor, which is claimed to boast much-improved bottom-end and mid-range power. With one day on the bike, however, we’ve found that the bike doesn’t quite deliver in both areas. As delivered, our test bike was fat on the bottom and had poor throttle response. Honda’s Eric Crippa made a couple quick turns on the carburetor air screw that seemed to help clean up the throttle response, but the bike’s low-end snap still pales in comparison to that of the Suzuki RM, Yamaha YZ and Kawasaki KX. Although the bottom-end leaves you wanting more, the mid-range hit is quite possibly the strongest we’ve ever encountered in a stock bike. As the rpms begin to rise, the CR power plant really comes to life and things begin to happen in a hurry! Aggressive riders who ride with plenty of throttle will hardly miss the low-end punch, as the beefy hit in the middle nearly makes up for the soft initial pull. Even better, the power keeps pulling and pulling, well into the upper echelons of the rpm range.

Revving the bike out in each gear is just as effective as grabbing the next gear and taking advantage of the meat of the powerband. Bottom line? The CR250R still isn’t a low-end monster, but the rest of the powerband is golden. With some gearing and/or slight intake modifications (Moto Tassinari V-Force, Boyesen Rad Valve, etc…) we’re sure the bike could be made better for riders who like to roll their throttles open.

With a host of improvements to the chassis and pretty much the same good feel in the suspension, the bike tracked beautifully down the rough straights and through the rolling and turning whoop sections. Cornering and diving into the inside ruts is what was the most fun on the CR250R. The bike settles in nicely and is perhaps the easiest bike to set up in tricky corners. The suspension has some new features, but none drastic enough to notice over the 2004 model. We made a few adjustments to the compression clickers and made it more comfortable for the rough terrain, but that’s an issue that changes between rider and track. We’ve long been fans of the CR250R’s suspension and handling performance, and this year is no different.

Overall, the 2005 Honda CR250R is a solid package that can be lethal in the hands of the right rider. Lack of low-end power remains the only chink in the CR250R’s armor, but we’ll continue to experiment with carburetor settings in an attempt to coax more low-end out of the red bike. Stay tuned!

To see the new bike in action, click the video link under the first photo at the top of the article.

NEW FOR 2005

A completely new engine design and a host of chassis improvements create a brandew CR250R–a machine destined to be a winner in 2005.

Features & Benefits

New for 2005

  • New cylinder design features RC exhaust valve housed in removable case for improved sealing and performance.
  • New precision-cut stainless steel cylinder base gasket and revised port timing for improved bottom-end and mid-range power.
  • New cylinder head combustion chamber shape for improved bottom-end and mid-range power.
  • New one-piece exhaust valve for improved sealing.
  • New piston dome shape for improved intake charge flow.
  • New piston features single keystone piston ring for reduced friction and improved sealing.
  • New crankshaft design for improved drivability.
  • New crankcase with redesigned intake port for smoother air flow and increased journal thickness to decrease crank deflection.
  • New six-petal reed valve with narrower profile for stronger bottom-end power.
  • New reed valve mounting angle to improve charge flow and top-end power.
  • New carburetor settings to match power characteristics of engine.
  • New shift fork shaft, shift forks and shift drum for improved shifting performance.
  • New ECU mapping and RC valve control settings to match new engine power characteristics.
  • New exhaust pipe shape has increased volume for improved low- to mid-range power.
  • Thicker radiator core (from 24mm to 28mm) improves cooling capacity to handle extra power.
  • New front axle placement for improved fork action and turning.
  • New swingarm features a dual-axis, double-taper design with a large cast aluminum cross member that is lighter weight and stronger.
  • New rear hub is stronger and lighter.
  • New rear shock valving for improved bump absorption
  • New Honda Racing-inspired graphics.

Engine/Drivetrain

  • Liquid-cooled two-stroke single-cylinder engine with 66.4mm x 72mm bore and stroke and 8.5:1 compression ratio.
  • Air intake boot is shaped for direct airflow, contributing to strong low-speed engine performance.
  • Foam gasket between airbox and air boot for better sealing and airflow management.
  • Lightweight 38mm flat-slide Mikuni TMX carburetor provides both initial throttle crispness and instant throttle response to complement the engine’s power character. Carburetor now has throttle position sensor (TPS) to calibrate timing with exhaust valve for improved power delivery.
  • Crankcase reed induction with carbon fiber six -petal reed valve contributes to excellent off-idle throttle response and top-end and over-rev power delivery.
  • RC-style exhaust valve features an NSR road racing-inspired rotary flap design with electronic control. The electronic control module uses engine rpm and throttle (TPS) opening to calculate exhaust valve position and signal a DC servo motor to adjust the RC valve, providing both a smooth transition from low- to mid-range rpm and a broader torque curve.
  • Exhaust header and expansion chamber are designed to maximize top-end power delivery.
  • A 16-bit CPU incorporates both the DC capacitive discharge ignition and exhaust valve servo control, producing immediate data calculation and extremely accurate ignition and exhaust valve timing for maximum performance.
  • Dual radiators permit forward engine placement and provide significant cooling capacity.
  • Steel water-pump gear for excellent reliability.
  • Eight clutch plates provide significant surface area to handle the engine’s torque while carefully matched clutch springs provide a light feel at the lever.
  • Clutch damper design improves rear suspension feel and action while accelerating over bumps.
  • Lightweight magnesium clutch cover.
  • Durable five-speed close-ratio transmission offers consistent performance in demanding conditions.
  • Primary kickstarting system allows starting in any gear.

Chassis/Suspension

  • Revised suspension settings deliver more controlled suspension action along with a plusher ride.
  • Third-generation twin-spar aluminum frame delivers superior rider comfort and maneuverability.
  • Semi-double-cradle 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.
  • 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 to help reduce unsprung weight.
  • Front wheel features large-diameter front axle and wide wheel-bearing span for additional rigidity.
  • Optional 20-inch front wheel improves cornering traction and rider comfort.
  • 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 rods features 12.4 inches of travel, 16-position rebound damping adjustability and 16-position compression damping adjustability. The inner surface of the front fork outer-tubes receives the same honing treatment as works bikes for low-friction operation.
  • Pro-Link® single-shock rear suspension features a fully adjustable Showa rear damper and12.6 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’s 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 reduce 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 rotors provide optimum braking control.

Additional Features

  • Aluminum Renthal 971 bend handlebar.
  • Frame design allows sidecovers to have larger air intake ducts, contributing to significant airflow in the mid- and upper-rpm ranges.
  • Carefully developed ergonomics position the rider’s legs at the narrowest cross-section of the frame for improved comfort while maintaining excellent handling feel.
  • 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.
  • 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.
  • Wide, cleated stainless steel footpegs are improved for self-cleaning, corrosion resistance, provide excellent grip and fold for extra ground clearance.
  • Cleated rear brake pedal, shift lever and folding shift lever tip are made of lightweight aluminum.
  • Adjustable front brake lever for maximum control.
  • Quick-adjust clutch perch.
  • Dunlop D742 front and D756 rear tires for optimum traction and cornering.
  • CR handlebar holders provide three different mounting positions: standard CR®250R holder provides neutral position and optional holder (CRF®450R/CR125R/CRF250R-type) provides +/-3mm fore or aft position to match rider preference.
  • Works-type handlebar grips add to rider comfort.
  • Front disc brake cover helps protect rotor and caliper from damage.
  • Removable rear subframe allows easy maintenance.
  • Washable, two-stage foam air fiickstarting system allows starting in any gear.

Chassis/Suspension

  • Revised suspension settings deliver more controlled suspension action along with a plusher ride.
  • Third-generation twin-spar aluminum frame delivers superior rider comfort and maneuverability.
  • Semi-double-cradle 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.
  • 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 to help reduce unsprung weight.
  • Front wheel features large-diameter front axle and wide wheel-bearing span for additional rigidity.
  • Optional 20-inch front wheel improves cornering traction and rider comfort.
  • 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 rods features 12.4 inches of travel, 16-position rebound damping adjustability and 16-position compression damping adjustability. The inner surface of the front fork outer-tubes receives the same honing treatment as works bikes for low-friction operation.
  • Pro-Link® single-shock rear suspension features a fully adjustable Showa rear damper and12.6 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’s 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 reduce 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 rotors provide optimum braking control.

Additional Features

  • Aluminum Renthal 971 bend handlebar.
  • Frame design allows sidecovers to have larger air intake ducts, contributing to significant airflow in the mid- and upper-rpm ranges.
  • Carefully developed ergonomics position the rider’s legs at the narrowest cross-section of the frame for improved comfort while maintaining excellent handling feel.
  • 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.
  • 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.
  • Wide, cleated stainless steel footpegs are improved for self-cleaning, corrosion resistance, provide excellent grip and fold for extra ground clearance.
  • Cleated rear brake pedal, shift lever and folding shift lever tip are made of lightweight aluminum.
  • Adjustable front brake lever for maximum control.
  • Quick-adjust clutch perch.
  • Dunlop D742 front and D756 rear tires for optimum traction and cornering.
  • CR handlebar holders provide three different mounting positions: standard CR®250R holder provides neutral position and optional holder (CRF®450R/CR125R/CRF250R-type) provides +/-3mm fore or aft position to match rider preference.
  • Works-type handlebar grips add to rider comfort.
  • 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.

CR250R Specifications

Engine Type: 249cc liquid-cooled single-cylinder two-stroke with electronically controlled RC valve
Bore and Stroke: 66.4mm x 72mm
Compression Ratio: 8.5:1
Induction: Six-petal crankcase reed-valve
Carburetion: 38mm Mikuni TMX flat-slide with throttle position sensor (TPS)
Ignition: CD with three-dimensional mapping and electronic advance
Transmission: Close-ratio five-speed
Final Drive: #520 chain; 13T/48T

Suspension
Front: 47mm inverted Showa cartridge fork with 16-position rebound and 16-position compression damping adjustability; 12.4 inches travel
Rear: Pro-Link Showa single shock with spring preload, 17-position rebound damping adjustability, and compression damping adjustment separated into low-speed (13 positions) and high-speed (3.5 turns); 12.6 inches travel

Brakes
Front: Single 240mm disc with twin-piston caliper
Rear: Single 240mm disc

Tires
Front: 80/100-21
Rear: 110/90-19

Wheelbase: 58.3 inches
Rake (Caster Angle): 26.50 °
Trail: 109.8mm (4.32 inches)
Seat Height: 37.1 inches
Ground Clearance: 13.3 inches
Dry Weight: 213 pounds
Fuel Capacity: 2.0 gallons
Color: Red

r 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.
  • CR250R Specifications

    Engine Type: 249cc liquid-cooled single-cylinder two-stroke with electronically controlled RC valve
    Bore and Stroke: 66.4mm x 72mm
    Compression Ratio: 8.5:1
    Induction: Six-petal crankcase reed-valve
    Carburetion: 38mm Mikuni TMX flat-slide with throttle position sensor (TPS)
    Ignition: CD with three-dimensional mapping and electronic advance
    Transmission: Close-ratio five-speed
    Final Drive: #520 chain; 13T/48T

    Suspension
    Front: 47mm inverted Showa cartridge fork with 16-position rebound and 16-position compression damping adjustability; 12.4 inches travel
    Rear: Pro-Link Showa single shock with spring preload, 17-position rebound damping adjustability, and compression damping adjustment separated into low-speed (13 positions) and high-speed (3.5 turns); 12.6 inches travel

    Brakes
    Front: Single 240mm disc with twin-piston caliper
    Rear: Single 240mm disc

    Tires
    Front: 80/100-21
    Rear: 110/90-19

    Wheelbase: 58.3 inches
    Rake (Caster Angle): 26.50 °
    Trail: 109.8mm (4.32 inches)
    Seat Height: 37.1 inches
    Ground Clearance: 13.3 inches
    Dry Weight: 213 pounds
    Fuel Capacity: 2.0 gallons
    Color: Red