Designed By Whom?
Designed by whom?
TDC
Kevin Cameron
WHO IS REALLY DESIGNING MOTORCY cles these days? We'd like to think that the answer is experienced, insightful engi neers, constantly pushing the limits of hu man knowledge. In certain respects, that is a reasonable answer. Consider the new R6 Yamaha, with its 1 7,500-rpm redline, its effective and light labor-saving die cast chassis and its single-butterfly, com puter-modulated throttle system.
On the other hand, the basic appearancc ofracing/sportbikes has changed little sinc€ the FIM decided, at the end of the 1957 season, that motorcycles must have barc front wheels and only frontal streamlining~ Compare this with nature's best stream lining-a trout or a salmon. A fish's largesi cross-section is up near the front, saving the rest of its length for a slow taper to th~ tail, recovering the energy given to the water that the foreparts have accelerat ed aside. The result is a very small wake and little loss to turbulence. Result: high speed on low power.
What passes for modern in motorcy cle design is as though we chopped off everything to the rear of the fish's gills, propped its mouth open, and stuck a tele scopic fork and wheel in it. Somewhere behind this remnant crouches the rider. As aerodynamics go, this is a nasty piece of work, for the lumpy presence of the front wheel disturbs airflow to the fair ing, after which nothing is done to recover the energy consumed in pushing this col lection of objects through the air. This generates a large, energy-rich turbulent wake and a drag coefficient perhaps as good as that of a bread truck. Because so little can be done to improve this 48-yearold creation, stylists enjoy the private joke of tacking on irrelevant supersonic style scoops and the flat planes of early stealth. Result: fuel consumption corn narable to that of small automobiles.
Better shapes exist, but people don't r like them. Harley-Davidson's famous c "whale" fairing, worked up in a Cal Tech s wind tunnel in 1969, has its largest crosst section up near the front and thereafter i tapers inward. Why don't people like it? It's plump-looking and smoothly roundt ed-much like the late-stealth shape of the t B-2 bomber. There are no trendy flat planes, no dart-like triangles, no decorat tor scoops. It looks fat and dated. r
When the F-il 7A Stealth fighter was designed in the 1 970s, computing power was insufficient to solve for the radar-re flecting properties of any but the simplest shapes-flat planes. The resulting shape doesn't fly very well, but electronic con trols make it manageable. By the time B-2 was in design, computing power had greatly increased, so aerodynamically more efficient curved shapes could be solved, as well. But we motorcyclists are stuck with inappropriate copies of 30year-old shapes-flat planes, darts and sharp edges. Marketing rules!
Will electronic controls boost motor cycle stability and transform every rider into an ace? It's claimed that on certain current MotoGP machines (see "Super Novas," Racewatch, this issue), the rider can pin the throttle and the on-board computer monitors wheelspin to deliver a perfect corner exit. When can I order? Don't hold your breath. 1ff gas my 2005 model too hard and incompetently tip over, any road rash is clearly my respon sibility. But if I think I can just whack the gas and let trick electronics handle it-and I still crash-who is responsible? ABS existed for 30 years before any mo torcycle-maker dared put it on a produc tion model, so the much more complex anti-spin/yaw-control technology I'm talking about may take a while. Engi neering by understandable fear of re sponsibility as seen by liability lawyers!
A great deal of vehicle engineeringsome say as much as 40 percent of R&D cost-is consumed in meeting the vanous emissions, noise and safety regula tions of the world's governments. This is fine, because we do want clean, quiet and safe vehicles, but it does make govern ment into a major partner in engineering. Consider just fuels. The decision to re move the poisonous but wonderfully ef fective anti-knock agent tetraethyl lead from motor gasoline resulted in a steep drop in fuel octane. Safe operation on lower-octane fuels requires reduced com pression ratios, which in turn cut torque and increase fuel consumption. On the other hand, the pressure of emissions standards forced motorcycle-makers to N develop the wonderful fuel-injection we now enjoy. Engineering by regulation! 7 Ducati engineer Filippo Preziosi main tains that most aspects of design are fixed ahead of time anyway, leav ing only details to engineering choice. Wheel diameter is what ever tire manufacturers are cur / rently making. Suspension and -~ brake components come from a very few major sources. Wheelbase is defined by the current compromise between short, for quick steer response, and long, to en able high acceleration and stable braking. The engine must be compact enough to put its cg adequately forward while leav ing room for the necessary radiator(s), intake airbox, fuel tank, rider and exhaust system. Engineering byconvenience!
All of this makes me hope that an out sider full of self-confidence may enter the sport with something more novel than drastically repositioned scoops. A fresh glance can sometimes beat decades of staring. It's not often that something re ally new appears. One example was the radical Norton "kneeler" of 1953, and another is Dan Gurney's long, ultra-low Alligator. Rex McCandless, designer of the kneeler, asked why engine, fuel and rider had to be stacked vertically. By put ting the fuel beside the engine, he cut frontal area by an amount equal to the height of a normal fuel tank. The ma chine was seen briefly, set a few records and was seen no more. No bucks, no Buck Rogers, as they used to say in NASA. Gurney's Alligator is long but its extreme lowness gives it rapid response in roll. Are these designs impractical or are they just unfamiliar? If the latter is true, public taste is the most powerful of all project engineers. Does it make sense to reject possibly good ideas just be cause they look funny?
