Wednesday, May 22, 2013
Ducati 848
The Ducati 848 is a sport bike, with a 849 cc (51.8 cu in) V-twin engine, manufactured by Ducati. It was announced on November 6, 2007 for the 2008 model year and replaces the 749, although the 848 model name was already listed on the compatible parts table for the 1098 fuel tank, giving away the secret a few months early. The 848 makes a tested 115.6 hp (86 kW) at 10,000 rpm and 62 lb·ft (84.1 N·m) at 8,250 rpm. With a manufacturer claimed dry weight of 168 kg (370 lb), the 848 undercuts its larger displacement sibling, the 1198, by 5 kg (11 lb). It shares many components with the 1098/1198 series of Ducati super bikes. It also shares its engine with the Streetfighter 848. Ducati also makes the Multistrada, the Diavel and the 1199 Panigale.
In August 2010, Ducati announced the 848 Evo, as the evolution of the model. The bike featured small revisions such as a black swingarm, Mono-block Brembo brake calipers, steering damper mount as well as some very minor engine revisions. It competes with other middle-weight supersport class sports bikes such as the Yamaha R6, the Honda CBR600RR, the Triumph Daytona 675 and the GSX-R600.
Changes from predecessor
Trellis frame
Developed in cooperation with Ducati Corse, the 848 Trellis frame uses a simplified tube layout from the Ducati 749 featuring main section tubes that are enlarged in diameter from 28 mm to 34 mm, while being reduced in thickness from 2 mm to 1.5 mm. The result is a 14% increase in rigidity and a weight saving of 1.5 kg (3.3 lbs) helping the 848 weigh in 44 lbs less overall than the 749.
Engine revision
While most of the chassis components are identical to the 1098/1198, the motor was an all new design in 2008. Producing roughly 116 hp at the rear wheel it out performs the revered Ducati 916 that had a hard time producing more than 100hp and even the upgraded Ducati 998 that produced 110 hp at the rear wheel. The "Testastretta Evoluzione" uses a 94 x 61.2mm bore and stroke for 849cc of displacement despite the bikes moniker of 848. The motor casings were constructed using a new vacuum die-casting method called Vacural that helps the engine weigh seven lbs less than the Ducati 749. The intake valves were increased 2.5mm from the Ducati 749 numbers to 39.5mm. The exhaust valves were enlarged 1.5mm to 32mm. The valve angles are identical to the Ducati 1098. The bike uses a pair of elliptical shaped 56mm throttle bodies fashioned after MotoGP designs.
The 2011 Ducati 848 Evo featured minor changes to the engine, including new Marelli throttle bodies, revised cylinder heads with straighter intake ports and reshaped combustion chambers. Ducati claimed these changes would result in a 6-hp increase, bringing output to 140 measured at the crank, however Cycle World Magazines first dyno test of the engine showed a mere 1.6 hp increase over the previous motor.
Wet clutch
Although the 1198 and 848 share many similar components, as per the 916/748 and 999/749 models, the 848 uses a wet clutch rather than the traditional dry clutch of previous superbikes from Ducati. The manufacturer claims it reduces weight, improves both service life and "feel" of the clutch and reduces noise. Ducati has in the past held to only dry clutches in accordance with marketing their bikes as obeying the design imperatives of racing above all, unlike, as Ducati would have it, ordinary street bikes. While a dry clutch "rattles like a bucket of rocks," Ducati and its adherents felt the clutchs "typical noise is music to bikers ears." The 848s wet clutch is a stark departure from this, because, "Ducati made it very clear that there is a new philosophy within the factory to develop each bike with specifications and capabilities that are aligned with the bikes target audience and intended environment."
Comparison with larger Ducati superbikes
The 848 shares more physical and technical design elements with the stronger 1098/1198 than its predecessor, the 749, did with the 999. In many cases the 1098/1198 and the 848 are identical right down to the part numbers.
The two bikes use the same bodywork, including the fuel tank. With the exception of the steering damper mount, the frame between the bikes is the same, which results in identical wheelbase and rake and trail numbers. The second generation 848 Evo features the same monoblock brakes and the same frame with the steering damper mount as the 1098/1198. The rear suspension, including the suspension linkage is the same, using identical Showa shocks. Many components of the exhaust system are shared, including the exhaust canisters that house the muffler and catalytic converter.
Despite the difference in engine displacement, the two bikes share valve angles and magnesium valve covers. The oil cooler and radiator are also very similar. The transmissions are different with the ratios on the 848 being closer together.
One of the more notable differences between the two bikes (aside from the engine) is the brakes. On the 848, the four-caliper Brembo front brakes are cast rather than machined monoblocs. The 848 requires greater braking effort than the 1098/1198, in spite of its lighter weight.