Honda CBR 600 RR on test

In 2017, the Honda CBR600RR Fireblade disappeared from the market, leaving enthusiasts saddened. Due to new Euro regulations, Honda made the decision to remove the 600cc supersport machine from their lineup. The costs of updating the small CBR to meet the stricter emission standards were deemed too high, especially considering the declining sales numbers at that time. Fortunately, things have changed, and Honda has now brought back the 600 to our streets. Not only does it meet the Euro5+ standard, but there are also numerous enhancements to various details. With new electronics, including riding aids, automatic gearshift, and an anti-hopping clutch as standard, expectations for the new CBR 600 RR are understandably high.

The Honda CBR600RR's 599 cc 16-valve DOHC in-line four-cylinder engine produces an impressive 121 hp (89 kW) at 14,250 rpm, with a peak torque of 63 Nm at 11,500 rpm. To achieve this, high-quality materials were utilized for the camshafts, valve springs, and crankshaft to guarantee both speed stability and longevity. The bore and stroke measure 67 x 42.5 mm, with a compression ratio of 12.2:1. After several years of absence in the European market, the CBR600RR's engine has been further refined and optimized for improved thermodynamic performance (enhanced combustion efficiency, intake and exhaust flow, emissions). In order to ensure a sufficient gas-air mixture flow for optimal power output at high engine speeds, the throttle valve diameter has been increased to 44 mm from the previous 40 mm.

The Honda Supersport benefits from carefully smoothed intake ducts and throttle by wire control, allowing for an ideally optimized, full-bodied mixture preparation. This is particularly beneficial at high engine speeds and under part-load conditions, where a sensitive and smooth response is crucial. The intake cross-sections have been designed to increase flow capacity by 2.2%. Additionally, the valve control has been adjusted: intake valves close 5° later and exhaust valves open 5° later, improving flow for the fuel-air mixture. The intake valves have a diameter of 27.5 mm and the exhaust valves have a diameter of 22.5 mm. To enhance cooling efficiency, the water jacket in the cylinder head is positioned close to the spark plug holes and exhaust valve seats.

The Honda Supersport features a 4-2-1 exhaust system with large manifold diameters to optimize gas flow at high engine speeds, while maintaining a lightweight design with thin wall thickness. This system includes a larger catalytic converter crucial for EURO5+ homologation. To prevent rear wheel stamping during hard braking and rapid downshifting, an anti-hopping clutch is utilized, reducing manual force required by 32% compared to conventional designs. Die-cast aluminum materials are used for the master and slave cylinders in the release mechanism, enhancing the feel of the clutch lever.

The electronic throttle management system (Throttle by Wire) of the Honda CBR600RR is derived from the CBR1000RR-R Fireblade and was developed based on the RC213V-S. It regulates the angle of the throttle valve in relation to the position of the throttle grip, taking into account various riding conditions such as speed, rpm, gear selection, airbox back pressure, outside temperature, and more. This ensures a completely natural throttle response and control, maintaining consistent controllability and feel across all power levels. The electronic package associated with the Throttle by Wire system also comes from the Fireblade. The Honda Selectable Torque Control (HSTC) offers 9 levels (plus off) of slip rate control, which adjusts based on the difference in speed between the front and rear wheels. It effectively prevents excessive wheel spin by modulating the fuel supply in a manageable way. Level 1 provides minimal intervention, while level 9 offers the highest level of control.

There are three riding modes available on the Honda Supersport: Fast, Fun, and Comfortable. Additionally, there are two user modes that can be customized by the rider. These modes can be easily adjusted while riding using the left handlebar switch, allowing the rider to set the HSTC level when in user modes 1 or 2. The motor power parameter can be adjusted from levels 1 to 5. The engine brake settings control deceleration when the throttle is closed, with levels ranging from 1 to 3, where 1 provides the strongest engine brake. Wheelie Control can be set at levels 1 to 3, or turned off completely, with level 1 offering the least intervention. Utilizing data from the CBR600RR's gyro sensor and wheel speed sensors, Wheelie Control helps maintain rear wheel torque and manage wheelies without sacrificing acceleration. The standard quickshifter enables rapid gear shifts by minimizing fuel interruption and ensuring smooth torque delivery after each shift, with three available settings for customization.

For the latest iteration of the Honda CBR600RR, the engineers at Honda have completely revamped the bike, focusing on enhancements such as weight reduction and improved performance. In order to fine-tune the overall package, they have integrated a six-axis Bosch Inertial Measurement Unit. This updated gyro sensor plays a crucial role in the bike's agility and handling dynamics, recalculating Honda's algorithms 100 times per second to effectively manage traction control and cornering ABS (a new technology for the 2024 model year). Moreover, the IMU is 2.5 kg lighter than the previous model's electronic "Combined ABS" system. The cornering ABS system utilizes a Nissin ABS modulator, which receives input from the 6-axis sensors, as well as deceleration and slip rates from the front/rear wheel sensors, to regulate brake pressure during straight-line acceleration and while cornering. Additionally, the new Rear Lift Control feature leverages sensor data to optimize braking performance while preventing rear wheel lift in high-performance riding scenarios.

The Honda Supersport features a twin-tube aluminum frame that houses the compact four-cylinder engine. With a wheelbase of 1,370 mm, a steering head angle of 24.6°, and a caster of 100 mm, this motorcycle offers precise handling. The swingarm, measuring 569 mm from the pivot point to the rear wheel axle, is made of lightweight aluminum, contributing to the overall weight of just 193 kg with a full tank. The CBR600RR is equipped with a fully adjustable Showa 41 mm Big Piston USD fork at the front and a Unit Pro-Link swingarm with a Showa monoshock at the rear, both fully adjustable. The braking system consists of two radially mounted four-piston calipers gripping floating 310 mm discs at the front, along with a single-piston caliper and a 220 mm disc at the rear. The cast aluminum wheels are paired with 120/70 ZR17 M/C tires at the front and 180/55 ZR17 M/C tires at the rear. The HESD (Honda Electronic Steering Damper) ensures optimal stability and handling by adjusting hydraulic damping based on speed, providing a safe and controlled ride experience.

In line with current trends, a significant amount of effort has been dedicated to aerodynamics in the development of the Honda Supersport. The cW value of 0.555 (drag coefficient) sets a new standard in the 600 supersport category for street-legal motorcycles. Additionally, the incorporation of fairing winglets generates downforce, enhancing front wheel grip for improved stability in high-speed corners and aiding in the prevention of unintended wheelies during aggressive acceleration. Drawing upon expertise from the Fireblade, Honda has tailored these features to suit its Supersport model. To further reduce weight, the motorcycle features compact LED headlights, small LED turn signals, and an LED taillight, along with a lightweight ABS modulator. The tank cover has been lowered by 10 mm to allow the rider to tuck in more effectively behind the windscreen. Positioned at a 38° angle, the windscreen maximizes aerodynamic efficiency in all riding positions on the track. The seat height stands at 820 mm.

The airflow to the water cooler and air intake duct for the airbox has been optimized for the Honda Supersport, along with the fairing keel that directs airflow around the rear wheel to reduce drag. These enhancements improve overall aerodynamics and reduce drag around the tires. The winglets on the Honda Supersport create downforce to maintain front wheel grip during corner entry, without affecting handling thanks to their vortex-suppressing design. The full-color TFT display on the Honda Supersport offers Street, Circuit, and Mechanic display options, including a shift indicator with five white LEDs for trackday use. Features like a lap timer, lap counting function, and best time display cater to racing enthusiasts. The Honda Supersport also includes the Honda Emergency Stop Signal (ESS) feature, which activates rear indicators during sudden, heavy braking to alert other road users, working in conjunction with the ABS modulator unit.

Honda once again offers several upgrade options for those looking to dominate the race track with precision. HRC has crafted a race kit specifically for the Honda CBR600RR-R to enhance performance and shed weight. This package is designed solely for track use, blending essential safety features from road riding with HRC kit components. The HRC Race Kit features an ECU control unit, wiring harness, cylinder head gasket, an oversized radiator, a high-performance exhaust system, as well as track-tuned front and rear suspension components and corresponding brake discs.

If you're familiar with the previous model, you'll feel right at home when you hop on the new Honda CBR 600 RR. Honda has stuck to the successful formula for this Supersport bike. It's user-friendly, sleek, and easy to handle. However, taller riders might find the seating position a bit cramped, especially on the track, affecting the overall riding experience. The placement of the footrests, positioned too far forward and high in relation to the seat, leads to elbows and knees bumping into each other during aggressive cornering. While this may be a drawback for track use, it's less noticeable during leisurely rides and can be easily addressed with aftermarket footrests.

Despite the challenges posed by Euro5+ regulations, the engine remains eager to rev, particularly in the higher RPM range. This is thanks to the 44 mm throttle bodies, now controllable via Ride by Wire technology for smoother operation. However, at lower and mid-range RPMs, the impact of the EURO standard restrictions is somewhat felt. Nevertheless, it's impressive what Honda has achieved with just 600cc while complying with current emissions standards.

For riders looking to push the limits on the track, many of the restrictions imposed by authorities can be lifted to unleash the full potential of the Honda Supersport. When it comes to the racetrack, the ABS performs admirably in wet conditions but can be overly cautious on dry surfaces. A dedicated track mode, similar to the one found on the Fireblade, would be a welcome addition. This mode would disable rear wheel lift-off detection during hard braking, allowing the ABS to only intervene on the front wheel to enhance deceleration performance significantly. The suspension system exhibits a similar behavior. While it performs well on a wet track, the Showa suspension components can feel slightly under-damped and produce excessive movement at higher cornering speeds on dry surfaces. However, for riders seeking comfort on country roads, this characteristic can actually be beneficial.