From Ducati's press material:
DUCATI 749/749S
The Ducati 749 Testastretta Superbike represents Ducati's sporting DNA. The 749 shares the same philosophy as the 999 Testastretta Superbike, Ducati's flagship motorcycle: world-beating performance, prize-winning design, together with a focus on rationalizing planning and production processes and the integration of parts. For the first time on a medium cylinder engine, Testastretta technology - a formula which has shown its power in the Superbike championship - has been integrated into the 749.
1) Engine
Compared to the previous generation Desmoquattro, the new Ducati 749 engine incorporates multiple improvements including a completely redesigned crankshaft, cylinders, and cylinder heads.
The 748.14 cc displacement is obtained with a 90 mm bore and a 58.8 mm stroke. The shorter stroke lowers the average speed of the piston resulting in a higher RPM redline, maximum performance, and improved reliability. Maximum horsepower reached at approximately 10,000 rpm. The cylinder heads now have a steep included valve angle of only 27 degrees; 12.5 degrees for the intake valves and 14.5 degrees for the exhaust valves. This allows a very compact and efficient combustion chamber. The intake and exhaust valves have increased in diameter to 37 mm and 30.5 mm, respectively.
The 749's Testastretta's desmodromic timing system has evolved significantly with improvements in the design of components and the use of advanced surface treatments, which result in longer maintenance intervals for the valve-train. New camshafts are improved and lighter and the closing camshafts now feature eight lightening holes. The lubrication and cooling ports in the cylinder head have been developed in cooperation with Ducati Corse using both CFD (computational fluid dynamics) and structural calculations. Both lubrication and cooling are improved and cylinder head stiffness is increased consequently improving cylinder to head sealing.
2) A revolutionary exhaust system
Designed to ensure maximum performance and compliance with the forecasted Euro 2 emission standard
The exhaust system and single-muffler have an innovative non-symmetrical layout. The paths of the manifolds and the high-volume single-muffler have resulted in a significant improvement in torque at the middle of the RPM range. The L-twin engine configuration uses exhaust pipes of different lengths. Optimally, exhaust pipes should be equal length.
The Ducati 749 solves this in a unique way by varying the diameters of the exhaust pipes to simulate equal length pipes, consequently equalizing pulse waves and back pressure. The 749 Testastretta complies with Euro 1 clean air standards regulation, and forecasted Euro 2 standards. This is accomplished with a three-way catalysed exhaust system.
3) The air intake circuit
Designed to increase performance while still limiting noise
The new larger air box has a volume of 12.5 dm3. Airbox sealing has been improved and is no longer sealed by the bottom of the fuel tank as with the 748. The air intake ducts draw fresh air through inlets positioned on the front upper fairing, and incorporate Helmotz resonators, reducing noise while not sacrificing performance. Additionally, the coolant reservoir has been integrated into the right air intake duct, reducing the number of components under the fairing and saving weight.
4) Integration of parts and ease of maintenance
The integration of the parts that make up the Ducati 749, makes repairs and maintenance easier.
The use of highly integrated subassemblies enables simpler and quicker assembly and disassembly, in addition to a clean uncluttered layout when the fairings are removed. The voltage regulator, ignition-injection control unit, battery, outlet for connecting the electronic tester and the principal components of the electrical system, have all been grouped in one unit positioned on the left-hand side of the engine. The alternator cover has a more compact size due to the use of rare earth rotor magnets (Samarium Cobalt) coupled with a more compact three-phase winding. The layout of the auxiliary parts on the left side of the engine allows easy access to the right side of the engine, greatly improving the ease of inspection and replacement of the timing belts. The cooling circuit now has a limited number of rubber hoses by utilizing a new coolant manifold with integrated the thermostatic valve and the water temperature sensor.
5) CAN line electronics simplify the electrical system
Technology emerging from the automotive industry applied to a motorcycle for the first time.
The major source of innovation on the electrical system is in the use of a CAN line (Controller Area Network) to which two nodes are connected: the instrument panel and the Magneti Marelli 5.9M engine control unit. This greatly simplifies and reduces the weight of the electrical system by limiting the number of electrical cable bundles and duplication of sensors on the motorcycle. The information from each sensor is sent to the closest processing unit, which then transmits the information to the network and the CPUs. The CAN line is a network consisting of only two wires that transmits the digital information. The instrument panel and the engine control unit use special hardware and software to recognize whether a certain train of impulses contains information that is relevant to the unit.
CAN line technology has made it possible to simplify by a large extent the electrical system of the Ducati 749, which in some sections is simply composed of only the CAN line wire pair.
6) The new instrument panel - more than just information but an active electronic unit
The instrument panel used on the Ducati 749 is an "intelligent" device that indicates all the information necessary for the rider. The new lightweight instrument panel on the Ducati 749 weighs only 400g, and is positioned vertically to compliment the narrow upper fairing. It is composed of a circular tachometer with a backlit dial and LCD panel, which indicates the engine coolant temperature, speed, odometer, battery voltage, air temperature and fuel consumption. The panel also indicates the time, routine service interval and anti-theft system status.
New for the 2003 Ducati 749 is an on-board lap timer, which is activated by pressing the engine starter button or by an optional infrared sensing device. For each lap, the instrument panel stores top speed, top engine rpm, over-rev occurrences, and the elapsed time.
Above the tachometer are the lamps for signalling ignition system faults, turn signal operation, low engine oil pressure, neutral, high-beam on, reserve fuel warning, and an over-rev indicator with signals for 200 and 100 RPM before redline. The instrument panel controls the lights, which turn off automatically when the starter motor is running, or when the motor has been stopped for more than one minute. The LCD panel also displays a set of codes in the event of an engine control system failure. The codes are translated by consulting a table in the repair manual. The lighting of the instrument panel is automatically adjusted according to the external light conditions to ensure display visibility.
7) The frame and the double-sided swing arm
Engineered to ensure optimum weight centralization and distribution for greater stability and quicker handling
The Ducati Trellis frame uses the engine as a fully stressed member resulting in very high torsional rigidity in a lightweight package. Due to the elimination of the fuel tank as the airbox top seal, the new frame is now much slimmer, thus allowing the overall bike to be very compact.
Substantial efforts were made to ensure the optimum weight bias and a low center of gravity for the 749. The weight bias is 101 kg on the front and 98 kg on the rear (only on 749s) and the center of gravity is at the height of 460 mm.
The position of the engine, rider, and accessories determine the centre of mass on a motorcycle, and on the 749 are located as close to each other as possible, (mass centralisation). This dramatically affects the dynamic response of the motorcycle during braking, acceleration, and cornering. The result is a bike that is easier to ride and turns "quicker". It was for this reason that the technicians at Ducati designed each component with the highest level of integration and compactness, to allow a high density of the parts in a limited space, further contributing to mass centralization.
The double-sided, sand-cast, aluminium swingarm was designed to ensure optimum stiffness without increasing weight. The chain guard and rubbing block are integrated into one unit. The chain tension is maintained by two horizontal sliders that allow adjustment without changing the ride height or handling characteristics of the motorcycle.
8) The forks
Designed to guarantee the precise and consistent response of the front end
The fork crowns are moved 36 mm forward and the new lightweight upper crown is entirely machined from billet aluminium. All structural components of the Ducati 749 have been designed with the Finite Element Method (FEM) to lower weight, achieve optimum form, maximum resistance to stresses. The Showa 43 mm forks have 125 mm of front wheel travel and feature adjustable rebound and compression damping, and spring preload. The legs are treated with TiN (Titanium Nitride) on 749s, (the 749 has the same forks, but without TiN treatment). The lightweight hollow front axle has a 25 mm diameter to increase rigidity and improve handling precision.
9) The rear suspension
Perfect progression and full adjustability
The rear shock with 71 mm travel and 128 mm wheel travel is linked to the swing arm in a new lowered position and is adjustable for rebound and compression damping in addition to spring preload. The Ducati rear suspension linkage achieves optimum suspension damping progression and the unique reaction rod is adjustable in length to allow adjustment of the rear ride height without effecting spring preload.
10) The braking system guarantees maximum performance and safety
With the Corse four pad front calipers and the radial master cylinder, the braking system performance compliments the new high performance 749 Testastretta engine.
The new ultra-low and compact front brake and clutch master cylinders were co-designed with Brembo and are of radial design. Their compact design allows for increased steering lock angle and a lower front fairing. The clutch lever, the front brake, and the rear brake levers are all fully adjustable. The Brembo braking system consists of twin 320 mm steel front brake discs and a steel 240 mm diameter rear brake disk. The front discs are spaced farther outboard from the front wheel to improve the cooling efficiency of airflow. The thickness of the brake discs was reduced from 5 mm to 4.5 mm, and an increase of the inner diameter of the discs reduces unsprung weight and improves handling. The front brake callipers have four 34 mm pistons and four individual brake pads. Sintered brake pads are fitted to improve wet-weather stopping. The brake system was directly derived from extensive Ducati Corse racing experience. The aggressive stopping power of the Ducati 749 perfectly complements the bikes amazing acceleration and top-speed capabilities.
11) The ergonomics of the Ducati 749
Creating a perfect symbiosis between the rider and the machine
Great attention was paid to perfecting the interaction between rider and machine. The designers developed a riding position and control adjustability that allows optimum ergonomics, performance, handling, and control on the road and track. Fitting the bike to the individual rider's size and preference is accomplished with five-way adjustable foot pegs (only on 749s on the single seat version that is adjustable fore and aft by 20mm. In addition to this, on the 749s the rake is also adjustable (23,5 - 24,5). Tests with riders ranging from 1.6 meters to 1.95 meters were made to help determine the range of adjustment required to optimise the ergonomics of the 749. The layout of the 749 "loads" the front end of the bike appropriately for optimum handling without putting excessive weight on the rider's hands. The rear of the tank is rounded and low in the pelvic area, and narrow where the knees rest making the bike feel extremely compact. This ensures that the rider is comfortable and in control - key factors in building rider confidence. Ease of manoeuvring at low speeds was also improved by increasing the steering angle to 28.5 degrees.
12) Maximum part integration of the Ducati 749
Necessary for keeping weight low and making maintenance easier.
The integration and modularisation of all the parts that make up the Ducati 749 has resulted in clear benefits such as ease of assembly, ease of maintenance, lower weight, and keeping the bike visually clean". The 749 was designed with component quantity reduction as one of the key goals. In fact, a reduction of 230 pieces, a 30% decrease, was realized.
A few examples of the integration of multiple components into modular units and the resulting benefits are as follows:
The positioning of the main electrical components on the left-hand side of the motorcycle in a specially designed panel allows easy access to the timing belts for a check or replacement. This layout is further supported by the re-design of the cooling system, also positioned on the left-hand side of the motorcycle. A cooling fluid distributor manifold now replaces the rubber hoses, and includes the temperature sensor and the thermostat. Additionally the right air intake duct incorporates the expansion reservoir tank of the cooling system.
For more information go to the 749 page at Ducati's website: 749, 749S
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