Drawing The Line - Motorcycle Bodywork Design: Feats of Clay

As I write this, we're seeing the new models from the annual EICMA Show in Milan. The MV Agusta F3, an all-new 675cc triple, has been much anticipated and will probably be the star of the show. It's instantly recognizable as a smaller sibling of the F4, but appears to have no parts in common. It also looks to become a classic.

The bodywork, swingarm, frame castings and many smaller parts from footpeg plates to exhaust pipes are all subtly detailed with a high level of surface development. That's typical of what we've seen from MV in the past. "Surface development" is my term for the process of taking a simple shape, like a seat cowl, and introducing creases, folds, vents and other details to make the part hold the viewer's interest, to give it depth, and to make it beautiful.

Surface development can go right, as I think it has on the F3, or it can go wrong. Surfaces can be too simple or too complex. They can draw you in or turn you off. But how does motorcycle style evolve from a project proposal to the finished parts we see at a show or in the showrooms?

The design of a motorcycle's bodywork starts with two-dimensional drawings, either done by hand or with various E-drawing resources-CAD programs that can help to quickly build realistic images of the designer's ideas. A few drawings may get a project to the point where the decision is made to start making parts, but more likely dozens or even hundreds of drawings are produced to get everyone involved to the point where they understand the project's direction and agree it should go forward.

CAD programs can allow parts to be made directly from the information contained in the initial design drawings, and it's tempting for companies to take this route as it's the least expensive path to having actual parts in hand. But there is another route that's been around a long time, and it's one that may never be replaced by software.

The MV Agusta F3's styling was certainly developed through the use of clay. A model (usually full-size) of the motorcycle is built using some of the actual metal parts of the motorcycle plus structures of wood, foam, plastic, composites, etc., that approximate the sizes and shapes of the surfaces that the designer wants to establish. Over this model clay is applied in various thicknesses, maybe an inch or two depending on the details to be worked. This clay is combined with various chemicals to make it both workable and stable-soft enough to carve, smooth enough to show a surface that can mimic the metal or plastic of a final part.

The motorcycle model is solidly mounted on a surface plate-a strong, rigid platform that will allow very accurate measurements to be taken of the parts being worked on. Though once made by hand, these measurements are now made with scanners that make a digital map of the bodywork.

With the clay in place, the stylist basically works as a sculptor, cutting away clay, adding it in other areas, smoothing it, rounding it. It's hands-on work, physically demanding, a real workout. What emerges are parts that have the exact shape of those that will eventually be stamped in steel or aluminum, cast, laid up or injection-molded. The model can be viewed from every angle, with lighting varied from dramatic show effects to direct sunlight to photo-studio shading. The clay model can be shown to executives, owners and investors, and to focus groups to determine market reaction, as an accurate representation of the eventual production piece.

Tim Prentice, a designer friend who has most recently done the lead styling work (and clay) on the Triumph Thunderbird and Speed Triple, said it looked to him like the F3 had probably been worked on in clay for a year or more. It has the kind of intricate surface development that is only possible with many months of work. What he was sure about was that a bike like the F3 could not have been done directly from CAD. There are just too many details that show the earmarks of work in clay. Beautiful motorcycles are rolling sculpture, and most of them probably started as lumps of clay.

The MV Agusta F3 is further proof that the motorcycle is more than mere transport; it can also be a work of art. The 675cc triple was named the "Most Beautiful Bike" at last fall's Milan Show.