Roundup
ROUNDUP
AGAINST THE WIND
How fast, and how far a motorcycle can travel depends not so much on who builds the engine, but on what shape the engine is in. Shape, in this case, refers not to the number of miles since the last tuneup, but to the hulk that engine drags through the air.
As the Vetter High Mileage Contest, reported elsewhere in this issue, pointed out, at even normal highway speeds most of what your motorcycle does is push you through the air. And as we all know when riding through a headwind, the air pushes back.
Aerodynamics is important to motorcycle performance, perhaps more important than it is to automobiles. Lots of work has been done, but the information is not well known and the motorcycles we ride every day have not generally benefited from this knowledge. To explain some of this, consider the two basic parts of aerodynamic drag. These are the frontal area, which if your motorcycle were two feet wide and four feet tall and perfectly rectangular, would be 8 sq. ft., and the coefficient of drag, a measure how much force it takes to push an object through the air not based on its area. Supposedly a drag coefficient of 1 would be produced by a flat surface, like a piece of plywood. Multiply the drag coefficient times the area and then times speed squared and the air pressure, and you know how many pounds of force the air pushes against the shape.
Motorcycles come surprisingly close to flat sheets of plywood, two feet by four feet, when it comes to aerodynamic drag. A medium small bike with rider sitting normally might have an 8 sq. ft. frontal area. The drag coefficient is around 0.8 for that same upright rider. That’s about the same number as a travel trailer. It’s twice as high as an average car. A perfect shape would be a teardrop at 0.04. A teardrop on two wheels might be 0.08. That doesn’t mean much until the effects of change are considered. Using our mileage contest entrant for an example, if that 0.8 could be cut in half to 0.4, the bike would need about half the power to go through the air at the same speed. Mileage could almost double. If that drag number could be cut to 0.2, the top speed could nearly double. Imagine an Exciter 185 Yamaha that could go 140 mph. Then think what a sleek, streamlined CBX could do for top speed.
Other people have thought these thoughts and worked on the problem of streamlined motorcycles. In the Fifties, NSU created a series of streamlined motorcycles used to gather lots of speed records. The company was planning on fully streamlined roadracers and even streamlined street bikes based on the speed machines. In his book Exotic Motorcycles, Vic Willoughby describes the small experimental NSU, called the Flying Hammock. With a lOOcc, 15 bhp engine the little NSU reached 1 38mph at Bonneville. This was about 30 years ago. Even a 50cc moped engine propelled the NSU to 122 mph. While setting speed records for many small engine classes, NSU put a stock 125cc pushrod-operated four-stroke engine in the Hammock. With the 8 bhp engine pushing the streamliner at 62 mph for five hours, the NSU ran 312 mi. getting 250 mpg. The man behind the NSU effort, Gustav Baumm, was eventually killed in an accident and the project faded.
Much work on aerodynamics stopped when full fairings were banned in international roadracing after 1957. Until that time the fastest racers all had dustbin fairings, completely enveloping the front wheel. The major motorcycle factories tested the fairings in wind tunnels, though only Moto Guzzi had its own wind tunnel. Perhaps that’s why the Moto Guzzi Singles had the lowest reported drag coefficient of 0.34, a figure about equal to the best-shaped current production cars.
Most recent aerodynamic work was done by Kevin Cooper for Can-Am, when Can-Am was hunting speed records. Cooper’s experiments showed that the production roadracing fairing for the CanAm lowered the drag coefficient to only about 0.6. The drag coefficient of a later Can-Am fairing, after the shape had been carefully modified to reduce the wake size, was 0.27, even with the same frontal area.
Fully streamlined motorcycles, at least the good ones, have been measured with» drag coefficients around 0.1. Could any form of street bike have such low drag? Probably not. Even with lights faired in plastic shells and the rider fully enclosed, the requirements for engine cooling openings and leg openings so the rider can hold the bike upright would bring the drag fig ure higher than 0.1. A figure around 02 would be more likely for a highly stream lined street bike, something on the orde of the Rifle Fairing bike that won the Vet ter mileage contest.
It’s worth noting that the best stream lined two-wheelers have less aerodynamic drag than the best four-wheel streamliners, while production cars all have
much better streamlining than production motorcycles.
There are barriers to more streamlined motorcycles. Streamlining often adds weight, which would hurt low speed accel eration most noticeably. Keeping '"jntal area as small as possible requires unconventional riding positions, either prone like a roadracer, or laid back like the original NSU. It’s hard to be cool when you’re laying down. Getting the smallest area and the lowest drag usually requires a long, thin shape, and that usually requires a longer than normal wheelbase. Longer wheelbases affect the handling of a motorcycle, though some current experiments
with both wheels steering suggest some solutions for that problem. High speed stability can be a problem with streamlined rtorcycles that are too tall or have too tch side area.
all that going against a welltreamlined motorcycle, plus the unusual appearance, it’s easy to see why motorcycles have remained much the same in general appearance and configuration for so many years.
Besides, who needs a 150 mph, 200 mpg motorcycle ... except maybe people like us.
FIFTY FLIES
Marshall Roath read about Bill Herndan’s Mexico to Canada dash on a 50cc Honda and caught the bug. Hetndan’s 102 hours, 58 min. were just too long for a good 50cc machine, he thought, so he decided to pack up his Puch and set a new record.
Originally the 48-year-old Roath and Steve Berger were going to ride two Puchs on the run, the 50/6 model Roath would ride and a specially modified GT50 moped, accompanied by a support van, crew and parts. They left the Mexican border at San Ysidro at dawn, May 19, having guards verify the time and mileage on the tiny bikes. Dodging freeways, where the little motorcycles aren’t legal, added time and distance to the effort, but they managed. At the high elevation of the California desert the moped slowed. It couldn’t run 45 mph. Deciding to concentrate on the speed record, the lower power moped was put into the van at Indepen: dence and Roath continued up Highway 395 on the faster 50. Most of his riding was done flat out, running near 60 mph. After 14 hours and 22 min, the first day ended, 480 mi. after it had begun.
When the route veered off 395 to Interstate 80, it left California and the Puch could travel on the freeway and make better time. Lots better time, it turned out, when the 12 hour, 11 min. day ended with another 552 mi. on the little Puch. The final day was even shorter, 1 1 hours and 14 min. to cover 455 mi. ending at Rykerts, British Columbia. The 1 500 mi. course re-
quired a total time of 58 hours and 22 min., only 38 hours of which was spent on the road. The tach remained between 8000 and 10,000 rpm for most of the route, and the bike was entirely troublefree, according to Roath.
SAFETY IN REGIONS
An east central regional office, serving Alabama, Illinois, Indiana, Kentucky, Michigan, Mississippi, Ohio, Tennessee, West Virginia and Wisconsin has been opened by the Motorcycle Safety Foundation (MSF). The office is located in Knoxville, Tennessee.
The east central regional office, headed by Meredith Gibson, will handle motorcycle safety education in the 10 states. Projects in licensing, research and public information will be coordinated by MSF headquarters in Linthicum, Maryland, with assistance through the regional office.
Information on programs in the east central regional states may be obtained by contacting the MSF East Central Regional Office, 301 Gallaher View Road, Suite 105, Knoxville, Tennessee 37919, phone (615) 691-5771.
GOODBYE GOODYEAR
Goodyear motorcycle tires are going out of production. Citing a rise in production costs and a decline in the motorcycle tire market, Goodyear Tire President Scott Buzby said the company “had no reasonable alternative to withdrawl.”
Goodyear will continue to produce specialized motorcycle tires for racing at its technical center, keeping the company name alive in motorcycling. Goodyear produces original equipment tires for some Harley-Davidson and Kawasaki bikes.
GOD SAVE THE HESKETH
Not a lot of encouraging motorcycle news has come from the British industry in recent years, but there has been the Hesketh, the British lOOOcc V-Twin roadster developed by Lord Alexander and his crew of merry men. A lot of work has gone into the design, and though the production was delayed by the discovery of a shifting problem, Heskeths have entered production.
All is not well, however. The company is short of capital, in the hands of a receiver, and running into resistance meeting various export laws. Noise laws are the biggest problem to selling the Hesketh in other countries, not just the U.S. As for the money matters, outside sources of capital are being approached. There are still no U.S. importers. What it would take to get a Hesketh to pass U.S. sound and emission tests, nobody knows yet. (All this information comes to us relayed by the British press.)
There is another British bike on the horizon, though. It’s the Norton, with that long-rumored Wankel-type engine. Stories of the Wankel Norton must go back at least to Winston Churchill’s time, and they are still with us. Getting better, even. The latest reports from usually unreliable sources say the engine—just the engine minus gearbox, not complete motorcycles—has gone into production. Because the design is so different, Wankels aren’t classified by displacement. Instead, the Norton rotary is reported to produce 85 bhp and weigh about 60 lb. (For comparison, the Norton 850 Twin weighed about 85 lb. and produced maybe 55 bhp.) This kind of power to weight ratio is a match for good two-strokes. One of the more unusual features of this rotary is the cooling for the rotor, always a problem with rotary engines. On the Norton the intake breathes through the rotor, cooling the rotor before the mixture goes through an air-to-air intercooler and into the engine. Because the engine is just a giant air pump, it uses its own air for cooling of the rotor. Clever these Brits.
INTEREST IN BIKES
Interest on motorcycle loans will remain deductible on federal income tax. When Sen. Harrison Schmitt of New Mexico proposed tax law revisions, he wanted to eliminate any deductions for interest on loans for recreational vehicles, including motorcycles. Objections from the AMA and others have changed the plan, with the Senate Finance Committee finding other ways to extract $20 billion.
MSF MOVES
Motorcycle Safety Foundation (MSF) offices will move from Linthicum, Maryland, to Chadds Ford, Pennsylvania, in late October 1982.
“With education activities shifting to our regional offices, we no longer need to maintain training facilities at headquarters. Fower operating costs resulting from our relocation means more money will be available to aid program development,” says MSF president Charles H. Hartman.
Effective October 15, 1982, the Foundation’s mailing address will be: Motorcycle Safety Foundation, National Headquarters, P.O. Box 120, Chadds Ford, Pa. 19317.
The Motorcycle Safety Foundation will be headquartered approximately two miles west of the Brandywine River Museum on U.S. Route 1 in the Chadds Ford West Office Complex.
In addition to the new Chadds Ford site, the Foundation maintains three regional offices which are located in Columbia, Maryland; Fair Oaks, California; and Knoxville, Tennessee. A fourth regional office is scheduled to open in the DallasFort Worth, Texas area in September.
FALL FUN
For the second year. Steamboat Springs, Colorado is hosting a combination of motorcycling activities in and around the town Sept. 18 and 19. On Saturday will be the Denver to Steamboat Fall Color Tour and Rally, combined with a vintage bike show. The next day streets through Steamboat Springs will be closed and motorcycles of all classes will race. Practice starts at 9 a.m. for the production, modified, formula, superbike, vintage and big Twins. Cost of admission is $2.50 including entry button and race program.
Information on the vintage show and race is available from (303) 879-2913. To find out more about the Denver to Steamboat tour, call (303) 879-7072. Races are sanctioned by the Mountain Roadracing Association. Sponsorship for the event comes from the local Chamber Resort Association, the Timberline Trailriders and Kawasaki.
A WHAT-CYCLE
How it can be called a motorcycle, we don’t know. But the people who sell this Autocycle claim it can be licensed as a motorcycle, though it looks like it has four wheels. The Autocycle is a streamlined, narrow, motorcycle-based vehicle, with four unusual wheels. The big wheels are positioned in front and back, just like a motorcycle. Then come two smaller wheels, outrigger fashion, on the sides.
The manufacturers claim that the Autocycle can exceed 120 mph or get over 100 mpg, all with a 250cc Honda Twin for
power. If the Autocycle looks like anything else, it might be the BD-5 aircraft, a tiny experimental airplane that just happened to be designed by the same person, Jim Bede. Bede is a well known aeronautical engineer, who has been credited with the design of several very high performance aircraft.
Tomorrow Corporation (440 Hunters Hill Dr., Chesterfield, Mo. 63017) is selling complete Autocycles for $3995, assembly kits for $2195, plans for $20 or information kits for $5. Œ
