Repsol driver´s bikes

Different means, same destination
Honda RSW 125cc, Aprilia RSW 250cc and Honda RC211V MotoGP; the three of them will be with no doubt protagonists if the 2003 season.
Three thoroughbred racing bikes with some similarities the three are World Champion candidates in their respective classes and big differences. Starting from the same concept two wheels, a chassis, an engine, brakes and suspensions -, their configuration, performance and results on the track feature three completely different worlds. BrakesDani Pedrosas Honda RSW 125 has a single steel 296-mm brake disk, with two opposite piston callipers in the front and one 192-mm in the rear. As of this season and after the changes made in the regulations, mainly to reduce costs, both the Honda RSW 125 GP and the Aprilia RSW 250 GP of Fonsi and Toni use steel disks instead of the former carbon discs. Fonsi Nietos Aprilia has two 255-mm discs in the front, with radial 4 opposite-piston callipers and a single 230-mm disc in the rear, grabbed by a 2-piston calliper. Valentino Rossis Honda RC211V is the best provided, with two carbon brake discs in the front, with radial callipers having four opposite pistons, i.e. a braking system capable to turn the bike upside down by simply pressing the handlebar with a finger. The rear is fitted with a single 195-mm steel disc. Engine configurationThe displacement, power and cycle two strokes against four are not the only differences. Each of the bikes has a different configuration, in most of the cases due to limitations imposed by the regulations. The most daring and innovative with regard to the concept is Rossis Honda RC211V, with a four stroke engine, five cylinders into V, three to the front and two to the rear, and an electronic injection fuel system. Next is the Aprilia RSW 250 GP, a two-stroke engine with two cylinders into V, fed by 2 carburettors, and then there is the Honda RSW 125n GP, a two-stroke engine as well, fitted with the simplest engine of the three, a single-cylinder fed by a single carburettor. Fuel tankEach of them with a different capacity, the most interesting peculiarity is probably the location of the Honda RC211V tank. Both Nieto and Elias Aprilia 250 GP and Pedrosas Honda 125 GP, have the tank located in the most traditional position, i.e. above the engine, fitted into the U of the frame beams. In the Honda RC211V, trying to improve the bikes overall stability with a full tank, the usual tank is a false one and the real tank is located in the centre of the bike, under the seat, thus changing the bikes centre of gravity. With a maximum capacity of 24 litres for the Honda RC211V, complying with the technical regulations, the tank of the Aprilia RSW 250 GP has a 23-litre capacity, while the smaller sized tank is the one of the Honda RSW 125 GP, with only 14 litres. Exhaust configurationThree completely different exhaust configurations, mainly determined by the engines number of cylinders. Pedrosas small Honda RSW 125 GP has a single exhaust, exiting to the front, located on the left-hand side of the bike and with the silencer at the height of the rear tyre. The Aprilia RSW 250 GP, with its two cylinders into V, has one exhaust on the left-hand side, pertaining to the front cylinder and the second exhaust exiting from behind the rear cylinder located under the seat unit. And last but not least, the five cylinders of the Honda RC211V turn the exhaust system of this bike into a true work of art. Three exhaust manifolds emerge from the three cylinders forming a single exhaust located on the right-hand side of the bike. Two exhaust manifolds come out of the two rear cylinders at the back, that form a single exhaust located under the seat unit. Fuel systemDifferent solutions with regard to this aspect, depending very much on the different configurations of the engines. The smallest and simplest, the Honda RSW 125 GP, has a single, 38-mm Keihin carburettor located at the back of the cylinder, and in opposite direction to the exhaust manifold. Both DellOrto 42-mm magnesium carburettors of the  Aprilia RSW 250 GP, are located at the right-hand side of the engine. And the option chosen by Honda for its RC211V, is to leave out carburettors and supply their engine with an electronic injection system, with the injectors located in the middle of the V made up by the five cylinders. Air intakesIn order to let as much air as possible into the cylinders, the three bikes are fitted with a different number of front air intakes in different locations. Pedrosas Honda RSW 125 GP has a horizontal central intake on the front side of the fairing that canalises the air through the right-hand side directly into an airtight airbox, whose task is to increase the amount of air flowing into the cylinders at high speed. Thanks to this effect, called dynamic pressure, the power of the engine is slightly increased. Something similar happens in the Aprilia RSW 250, but the front air intake is located at the upper right-hand side of the fairing, while the airbox is beside the engine, perpendicular to it and in the fairing. And last but not least, the Honda RC211V has two front air intakes that go through several slots of the frame beams, and into the airbox, located under the false fuel tank in the centre of the V made up by the five cylinders. SuspensionsThe three bikes have opted for similar solutions for the front end, with inverted forks, though with different sizes and from different suppliers. Both Honda bikes use Showa suspensions, 35-mm diameter for the RSW 125 GP and 47-mm diameter for the RC211V, while the Aprilia RSW 250 GP uses an Öhlins 45-mm fork. The common solution for the rear end is a monotube shock absorber, but Hondas solution for the RC211V is worth an extra mention. In this bike, instead of attaching the shock absorber to the chassis as usual and as it is made by the Honda RSW 125 GP and the Aprilia RSW 250 GP, its absorber is directly attached to the rocker switch. Both the front and the rear end suspensions of the three bikes have countless setting possibilities, be it extension, compression or hydraulics. FuelFour-stroke engines with natural intake, as those used in MotoGP need a different kind of fuel than two-stroke engines. This doesnt mean that fuel developed for two-stroke engines cannot be used for four-strokes, but in high level competition, in order to reach the highest performance, it is necessary to adapt the fuel to the specific function and design of the engine. Four-stroke engines are more complex and sophisticated than two-strokes, basically due to their distribution system and high rating, and therefore it is necessary to use specific fuel components that adapt to their combustion system allowing for a good power delivery to make riding easier. Therefore, the fuel formulated for fast four-stroke engines, as MotoGP bikes, needs specific properties such as: – High calorific value- High self-ignition resistance (‘pinking’).- Carburetion stability- Progressive response to soft or abrupt acceleration.- Suitable combustion speed. Did you know that….  The carbon brake discs of the Honda RC211V work best with a temperature of about 300 and 500º C, while the steel discs of the Aprilia RSW 250 GP only reach 150º C.  The rear tyre of the Honda RC211V works under a temperature of between 120 and 135º.  Each engine type needs a different type of spark plugs, depending on the geometry, working temperature and flammability conditions of the air-fuel mixture..  Fuel can contain over 200 different hydrocarbons..  The Honda RCV211V has a new rear suspension system, the Unit Pro Link; a system, were the monotube shock absorber is directly attached to the rocker switch, as opposed to the usual chassis attachment..  The Aprilia RSW 250 GP is the only bike of these three that has a carbon fibre rocker switch, as opposed to the usual aluminium one. This material increases the overall stiffness of the chassis..  The circuit with less differences in lap times between MotoGP, 250cc and 125cc bikes in 2002 was the Sachsenring, venue of the German GP, where the MotoGP machines lapped only 326 seconds faster than the 125cc bikes..  And the circuit with the largest differences between the MotoGP, 250cc and 125cc bikes in 2002 was Río de Janeiro, venue of the Rio Grand Prix, where the MotoGP machines lapped 10238 seconds faster that the 125cc bikes. Second of the list is the Assen circuit, venue of the Dutch Grand Prix, where the MotoGP machines lapped 10236 seconds faster than the 125cc bikes..  The new maximum speed record in MotoGP was set by Loris Capirossi and his Ducati during the IRTA tests held in Barcelona, in March 2003. Capirossi reached 3282 km/h. The secret of their success… Honda RC 211V. Five-cylinder bike with four-stroke bike weight and dimensions, profiting from the new technical regulations. Strategic location of the fuel tank to change the overall centre of gravity thus improving stability. Very balanced and competitive whole for all circuits Aprilia RSW 250. Very powerful engine with an optimal power range in middle and high levels. The fastest of its class. Very good chassis base, but needing exhaustive work for the set-up Honda RSW 125. Very handy and easy to ride. Engine with good response in slow gears . Recently fitted with new generation Showa suspensions The riders´s opinion Valentino RossiThe Honda RC211V had its debut last year, showing its potential from the beginning. I was impressed about the fact than such a young motorbike was able to perform on such a high level from the very start. I think that its the most balanced machine from the class; it has a powerful engine, its stable and agile, offers good traction and always transmits the necessary feeling to the rider. Altogether its a much more rational bike, easier to ride than the two-stroke 500cc bikes. Besides its much more permissive with the rider, you can make mistakes and rectify.           Nicky HaydenThis is the best bike Ive had in my life. Its handy, stable, very powerful, offers good traction and a very noble behaviour. What I probably like most is its excellent base and that its competitive to the limit on all circuits. It may not be the fastest of the class but its the most balanced. Its a homogeneous whole; the Honda RC211V is not a motorbike that stands-out for something special, but for all of its elements. Fonsi NietoThe engine is the best part of this bike. Its always been like this, the Aprilia bikes have always stood out for having one of the best engines of the class. The bike is very fast and has a very good power curve in the middle and high range. Another highlight is the way to take fast corners, which has a lot to do with the stiffness of the chassis. Its in the slower angles where you may have problems and thats the reason why we havent managed to make the Aprilia turn well yet, but I think that well soon solve that problem. Right now, the Aprilia is with no doubt the reference of the class and if you manage to have an optimal set-up you can be really fast. Toni EliasThe Aprilia has a very competitive, powerful engine and an optimal power curve in the middle and high range. We may have to work a little on the acceleration, but with regard to the top speed its with no doubt the fastest bike of the class. With regard to the chassis, the Aprilia is very stiff and therefore it is difficult to get used to its behaviour, but if you manage to have a good set-up its really a very competitive bike. The countless settings of the Aprilia is another strong point, but at the same time you have to know perfectly well which direction youre taking for your settings or else youll easily get lost. Dani PedrosaThe most outstanding aspect of my bike is that it is very handy and permissive with the rider; I mean you have a broad margin of error and its easy to ride. At the same time, the setting of the chassis is especially delicate and critic, but on the other hand, you can be very fast even if you dont have the perfect setting. The engines strongest point is the acceleration, especially in the three lowest gears. However we still have to work on the other three gears to improve their performance. But altogether and compared to other bikes of the class, the Honda RSW 125cc has a good competitive level.