Lightweighting a Street-legal Honda Racing Motorcycle

Honda has been racking up championships—Riders', Constructors' and Team—in MotoGP for years. And with the RC213V-S, it has created a lightweight bike based on a racing motorcycle that is street legal.

Honda developed the RC213V motorcycle for racing in the MotoGP class; in 2013 and 2014, it won championships in its class. This is in some ways a heritage model, given that the Honda Asaka R&D Center—the predecessor of the current Motorcycle R&D Center (HGA)—developed the RC211V for racing in MotoGP in 2002. HGA turned the bike over to Honda Racing Corporation (HRC) for production.

And it was HRC that gave rise to the RC213V.

Now there are those who would like the performance of the RC213V but who aren’t likely to be able to race around the Isle of Man.

So the people at HRC went to work and came up with the RC213V-S—a variant of the RC213V that’s street-legal.

Of course, in order to run the 1,000-cc, V4-powered bike on the streets HRC had to add things like head-lights and taillights, right and left rearview mirrors, a speedometer, muffler with catalyst, license plate holders, and the like. Things you don’t need when you go racing. (Although in some instances the horn might help.)

Here’s a remarkable thing about the RC213V-S in the context of the RC213V: the street bike weighs 172 kg (dry); the racing bike weighs only some 158 lb.

The people are HRC are serious about lightweighting.

An interesting aspect about the development of the bike is that Honda deliberately moves people from HGA—the R&D center—to HRC—the production-oriented operation. This is done to help drive inno-vation into the bikes being developed for production.

The bike is made in an exclusive workshop within the Honda Kumamoto Factory, where the process is manually intensive.

They produce just one motorcycle per day.

The RC213V-S has an aluminum frame. In order to make the frame as light as possible while maintaining the high torsional rigidity required for the performance bike, they use thin aluminum plates in areas where there is low contribution to rigidity. The parts are primarily assembled with TIG welding.

The bike’s swing arms are made of press-formed aluminum.

In areas where fasteners are required, they use machined titanium bolts. The bolts are manually tightened.

The fuel tank features press-formed aluminum sheet end faces. The tank is produced with TIG welding.

Not surprisingly, the fairing is made with carbon-fiber reinforced plastics (CFRP). The components are produced such that the thickness varies depending on the required strength and rigidity. This is accomplished by modifying the layers of carbon fiber pre-preg prior to autoclaving.

The bike doesn’t have a seat rail, but there is a CFRP monocoque structural seat cowl that is not only light but helps accommodate the fuel tank.

Honda’s approach to motorcycle racing is not one that rests solely on having the fastest motorcycle possible, though that is important. Also critical is having a bike that is the world’s easiest to maneuver.

The lightweighting of the RC213V and the RC213V-S is fundamental to this overall speed and maneuverability.