Yamaha introduces ride-by-wire motorcycle
By Mike Hanlon
October 30, 2005
October 31, 2005 Yamaha recently released the details on its 2006 R6 Supersport motorcycle. It has a fuel-injected 599cc four cylinder engine with four titanium valves per cylinder and revs cleanly to its 17,500 rpm redline, making maximum power of 133bhp at 14,500 rpm – that’s 221 bhp per litre – roughly the equivalent of a front-running MotoGP bike. It’s engine also has a slipper clutch as standard and it is the first production motorcycle with a ride-by-wire throttle. That’s right – there are still throttle cables but they run to a computer, not the carburettor slides.
A decade ago, a fast 600cc supersports bike had 90 bhp and weighed in at over 400 pounds dry. Then came the focus of world supersport racing, where 600cc four cylinder (and 750 twin cylinder) road machines are allowed just minor modifications to race on a prominent global stage. Suddenly the factories began to make racers out of the box - when Yamaha redesigned its 600 model in 1998 it shed 42 lbs and added 25 horsepower, winning a supersport title or two before it was swamped by the technological progress of the other manufactuters doing likewise. Indeed, Honda has now won the last four riders title and the last three manufacturers titles in the class thanks to its CBR 600 RR and this year Yamaha has decided to make another monumental effort to wrest back class leadership.
In the history of World Supersport racing, Honda leads Yamaha with 36 wins to 30, with Yamaha leading Honda in terms of podiums, 96-88. Suzuki is a distant third in both cases, with 16 wins and 61 podiums. From the raw stats, you’d think Honda and Yamaha had shared the spoils in Supersport competition at the highest level but that’s just not the case. Honda has won the last four individual world titles, and the last three manufacturer titles and this year Kevin Curtain’s second place in the title on a Yamaha was entirely due to his riding as the technologically superior Honda won easily until Charpentier had snared the title. Indeed, the Honda was so potent that even second-string teams were 5-10km/h quicker than the fastest Yamahas all year through the speed traps.
We expect that the third generation R6 will be blisteringly fast next year in Supersport racing and equally as exciting on the road, as every square millimeter of the machine has come in for a a redesign.
The design concept for the first model YZF-R6 that debuted at the Intermoto show in 1998 and went on sale in Europe and North America the following year was that of the "fastest and most exciting 600cc model on winding roads," and its actual performance quickly won customer support and set a new standard in the midsize supersport bike category.
The second generation YZF-R6 was released in 2003 and while a great road bike, it was gazzumped by Honda’s CBR600RR on the racetrack. Accordingly, the new "YZF-R6" builds on the initial design concept of the first generation and signals its intention to be the "fastest extreme supersports machine on the circuit.".Through the lavish adoption of the latest MotoGP technologies (ride-by-wire is not yet on the company’s MotoGP machinery), the third generation R6 machine looks set to scoot to the front of the pack .
1) high-revving engine As with all other aspects of the R6, the engine is newly designed. It is a liquid-cooled 4-stroke, DOHC in-line, 4-cylinder, 4-valve, fuel injection engine with a shorter (42.5mm versus 44.5mm) stroke than the previous engine. The bore x stroke specification come sin at 67 x 42.5 mm, where it was formerly 65.5 x 44.5 mm.
The intake/exhaust valve angles have been reduced from 14 to 11.5 degrees on the intake side and 14 to 12.25 degrees on the exhaust side, and the combustion chamber has been given a more compact design and fitted with larger diameter 27mm valves for intake and 23mm valves for exhaust (formerly 25 mm/22 mm).
With a high compression ratio of 12.8, this engine delivers maximum power output at 14,500 rpm. Under natural induction, the maxium power would occur at 13,000 rpm but the forced induction associated Despite the increased bore, it has been possible to keep the same bore pitch and maintain the same slim engine size thanks to exclusive casting technologies and adoption of a direct plated cylinder.
2) Yamaha Chip Controlled Throttle (YCC-T) YCC-T stands for Yamaha Chip Controlled Throttle is claimed to achieve outstanding response across the rev range. The ECU unit records the rider's throttle position and calculates the optimal throttle valve opening, operating the throttle valve by an electric motor drive; one feature of the system is that it actively initiates control of the volume of intake air. In order to handle the processing, the ECU has been beefed up to five times the capacity of the 2005 model’s ECU. In particular, optimizing the drive torque curve and intake airflow speed by controlling the opening degree of the throttle valve helps achieve a smoother, throttle response.
3) Fuel injection system with twin injectors Borrowed directly from Rossi’s winning MotoGP machine, twin injectors per cylinder have been adopted, with the secondary injector designed to supplement the main injector in the mid- to high-rpm range.
4) Titanium intake / exhaust valvesTitanium intake and exhaust valves have been adopted to ensure reliability in the super high-revving engine. Characterized by light weight and strength, the valves reduce horsepower loss and ensure reliability. Also, the strength of these titanium valves has been utilized to achieve a more compact design for the head assembly. Further weight reduction has been achieved through the adoption of aluminum retainers, which support the valves.
5) New 3-axis layout for best balance with the chassis With the new engine, the best relative positioning in relation to the frame is achieved in a newly optimized 3-axis layout for the crank, main and drive shafts. Compared to the 2003 and 2004 models, the crankshaft has been raised 3 mm and the main shaft lowered slightly to create a flatter triangle relationship than before. This layout contributes to the creation of a new frame shape with a more linear machine roll axis defined by the line connecting the head pipe, pivot axis, and rear axle. Once more, the basic geometries have been significantly influenced by the development of the MotoGP machine.
6) Slipper clutch adopted To ensure machine stability during downshifting when entering a corner, a slipper clutch has been adopted. This clutch features a mechanism that enables changes in the clutch plate pressure when torque force comes to bear on the crank from the rear wheel side to control the amount of torque being applied as a means of dealing with back torque.
7) Midship muffler and EXUPTo ensure excellent exhaust efficiency, concentration of mass, and aerodynamic characteristics, this model adopts a midship muffler. The design aims to make use of the space behind engine resulting from the shorter front-aft length of the new engine and the long rear arm. It also gives the machine a striking appearance.
EXUP was adopted for the first time on a 600cc sports model to control exhaust pulsation in the exhaust chamber and improve air intake/exhaust efficiency. One EXUP valve is placed at the point where the four exhaust pipes merge to make for a more compact design. The EXUP body is made of lightweight titanium.
8) Other stuff Also adopted on this model are: (1) forced air intake; (2) a semi-hydraulic cam chain tensioner; (3) a two-side-intake oil pump and water pump driven off the same shaft; (4) a one-way, single unit compact AC magneto; (5) a close-ratio 6-speed transmission; (6) magnesium head cover and case cover and (7) a 3-way catalytic converter equipped with an oxygen sensor. Chassis
1) New Deltabox frameA newly designed Deltabox aluminum frame has been adopted. Engine placement has been optimized thanks to the know-how gained from the MotoGP machine YZR-M1, optimization of the vertical, horizontal and torsional rigidity balance of the frame, including the rear arm, provides linear, sporty handling performance.
Like the frame of the YZF-R1, this new frame is a hybrid type composed of a combination of metal-mold cast parts and pressed parts, and as with the 2005 YZR-M1, the air induction passage is designed in a straight configuration that goes through the head pipe. Also, an efficient design makes use of the inside of the frame as air cleaner space. The fuel tank rail has been designed to lie as close as possible to the machine's roll axis to optimize torsional balance characteristics.
2) Rear arm with truss + box construction Like the frame, the rear arm is also a hybrid type composed of a combination of metal-mold cast parts and pressed parts, which slightly improve vertical rigidity and achieve a weight reduction of about 1 kg. Also, raising the pivot axis by 20 mm has improved the anti-squat effect. This brings out excellent running performance to reduce changes in movement when turning.
3) Front wheel weight distribution set up at 52.5% The new frame design, revised dimensions, adoption of a midship muffler and the slimmer tail assembly have increased the front wheel weight distribution by 1% compared to the existing model, bringing it almost to the level of a MotoGP machine at 52.5%. This provides a greater feeling of road hold for the front wheel and brings out outstanding cornering performance.
4) front and rear suspensions In order to provide greater freedom in settings, the following have been adopted: (1) initial load adjustment; (2) 2-way compression stroke damping adjustment; and (3) an upside-down front fork with 41mm inner tubes and a compression/rebound stroke damping adjustment function. The newly adopted 2-way compression stroke damping function is a feature that can be adjusted for both high- and low-speed to achieve settings for both the circuit and ordinary roads.
A new type of rear suspension has been adopted to provide the best match with the new frame. The link system for the rear suspension has been changed to a bottom-linked type and the link character has been optimized. Design efforts have been made to contribute to better concentration of mass. As with the front, a 2-way compression stroke damping adjustment mechanism has been equipped on the rear suspension. The damping can be adjusted separately for both high- and low-speed stroke to enable greater choice to accommodate different conditions and uses.
5) Other chassis stuff Also adopted on this model are: (1) lightweight aluminum rotor brackets and new front-brake pads; (2) an inner duct for the undercowl; (3) an aluminum rear mudguard stay; (4) a CF aluminum die-cast rear frame; (5) a TZ type aluminum chain puller that makes tire changes easier during races; (6) a forged aluminum side stand and (7) a lap time monitor.