Article: 19710101039

Title: ...And The Victim, Don Vesca

19710101039
197101010039
CycleWorld_19710101_0010_001_0039.xml
...And The Victim, Don Vesca
For A Sweet, If Somewhat Brief Period, His Gas-Powered Yamaha Was The Fastest Bike On The Face Of The Earth. How Was It Built? How, Indeed, Does It Feel To Ride That Fast?
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Cycle World
Bonnier
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article
SPECTATING AT BONNEVILLE is a rather abstract proposition. If you stand at the timing tower to watch the world’s former fastest motorcycle go by, it doesn’t look like it is going very fast. The salt flats are large, beyond easy human grasp. The motorcycle, encased in an 18-ft. aluminum shell, looks small.
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...And The Victim, Don Vesca

For A Sweet, If Somewhat Brief Period, His Gas-Powered Yamaha Was The Fastest Bike On The Face Of The Earth. How Was It Built? How, Indeed, Does It Feel To Ride That Fast?

SPECTATING AT BONNEVILLE is a rather abstract proposition. If you stand at the timing tower to watch the world’s former fastest motorcycle go by, it doesn’t look like it is going very fast. The salt flats are large, beyond easy human grasp. The motorcycle, encased in an 18-ft. aluminum

shell, looks small.

It whistles by two times. Innocuously. The noise barely tickles the ears. The average speed is announced: 251.924 mph. A new record. You shrug your shoulders and wonder why you have been standing out in the sun so long.

Don Vesco’s viewpoint is different. He’s inside that thing. It makes twostroke noises that rumble inside the hollow metal shell. Seated on little more than a pleated vinyl bathmat, strapped down with lap and shoulder harnesses, his legs straight out, he doesn’t have room to move his body more than an

inch or two. It is not very much like riding a motorcycle.

The interior is austere. A jumble-of tubing. The controls are scattered here and there, and have no labels. The steering is controlled by a set of short road-racing-style handlebars. Throttle twistgrip on the right bar, clutch lever on the left.

Vesco warms the machine by kick starting it from the outside, and shuts off a motorcycle choke lever when the two 350-cc Yamaha production road racing engines reach operating temperature.

He operates the rear brake with his right foot, and the gearchange lever with his left foot. Within reach of his right hand, there is a fuel shut-off valve and a

fire extinguisher pull cord. With his left hand he operates a tow release handle and an air valve handle, which retracts or extends balancing skids.

Vesco begins his run, towed behind a van. When he reaches 50 mph, he bump-starts the engines by releasing the clutch, then pulls the snap release to rid himself of the tow wire. After retracting the balancing struts, he must concentrate on steering and balancing the machine.

On a normal motorcycle, you use body lean and a slight twitch of opposite steering to change direction.

When Vesco wants to turn his streamliner to the left at speed, he paradoxically must turn his handlebars to the right slightly, and wait a second for the shell to lean.

Then, to prevent therrstreamliner from leaning too far to the left and falling over, he must steer even harder to the left to straighten the ’liner and stop the turn. “It steers backwards,” he

says, “so it takes some getting used to.”

Vesco has had a year to sort out handling problems. Even now, he must admit that his machine does some strange, frightening things as it gathers speed:

“It hunts at 180 mph. Then smooths out for a second. At 200 mph the handlebars shake and at 220 mph it starts to wander. It doesn’t want to go where I want to point it. After that, it is smooth on up to 250 mph. There’s no telling, though. It might start shaking again at 250 to 260.”

Indeed, there’s no telling, and no way to predict some of the incredible forces that must come into play at over 250 mph. The mystery is that Vesco, without the aid of slide rule engineering, can build a motorcycle streamliner that handles well enough to set a record and stay in one piece, on the ground.

It is a simple machine. The product of a man with good instinct for things mechanical.

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Vesco’s streamliner began life in the undetermined past as a wing tank from a U.S. Navy aircraft. Many twoand four-wheel Bonneville apparitions use old wing tanks, for it is cheaper to buy one than to design and fabricate your own aluminum shell. The wing tank has been the basis of the popular four-wheel Lakester class at Bonneville for many years. Using a wing tank is practical, and, as it has its origin in aviation, it is bound to have a modicum of aerodynamic soundness.

Vesco began work on the machine in May 1969, extending the shell and stuffing it with a strong network of 1.0-in. and 1.5-in. 4130 chrome-moly tubing. His greatest concern was creating a strong, crashproof driver compartment. So the greatest amount of triangulation and cross bracing of the frame structure may be seen forward of the engine compartment.

The skin of the craft was modified to create a cowling for the front wheel, as well as the tailfin, which is needed to give the tank directional stability. At the rear, an aluminum tube holds a parachute, which Vesco doesn’t use most of the time because of the long run-off distances available on the Bonneville flats. The chute assembly consists of a spring-loaded pop chute, which ejects automatically when the release is pulled and drags out with it the heavier main chute.

The suspension is “neo-motorcycle.” Vesco adapted a Yamaha TD2 road racing swinging arm, with Girling shock absorbers, to the rear of the machine. A leading link system of Vesco’s own design steers the front of the machine. It is unique in that the front wheel is mounted on a vertically traveling swinging arm, rather than a steering head/fork assembly. Steering is accomplished by turning the wheel on the axle by means of a bell crank. This sort of system is possible because the front wheel does not have to turn sharply, and the resulting advantage is a light, flex-free steering system. Resistance to flex is quite important at 200-mph speeds, where slight wheel imbalances, and inadequate dampening, multiplied by great centrifugal forces, could turn a run down the salt into a wobbling disaster.

Even so, Vesco had trouble in his first record attempts in August and October of 1969, and subsequently replaced the cable steering assembly with rods, linked by special aircraft ball joints, designed to reduce play in the system to a minimum.

As for the basic dimensions of the streamliner, overall length is 18 ft., extended 9 in. from last year to improve handling. Weight bias is forward: 60 front, 40 rear. Total weight is 650 lb. Wheelbase is 124 in., height is 36 in., ground clearance is 5 in., and body width is 27.5 in. The wheels are 19 in.

in diameter with integrally cast aluminum X-beam spokes. Having rims slightly narrower than WM3s, they are soon to be marketed by Custom Welding and Fabrication. The tires are special Dunlop record tires with a smooth rubber face only 0.070 in. thick; that facing is thin to prevent centrifugal weight build-up from ripping the tread off at high speed. To avoid distortion and heat build-up, the tires are inflated to 65 psi.

There is one interesting error in the construction of the streamliner, having to do with the fact that Vesco couldn’t check tire sizes before building the chassis. As a result, the front is 1 /2 in. higher than the back. Drily, Vesco observes that “it is making the front end light. I can tell because it is easier to achieve directional control when I roll the throttle off at speeds over 240.”

Power for the streamliner is produced by two 348-cc Yamaha R3 production road racing engines, placed in tandem, and running through the rear engine’s five-speed gearbox. The engines are rated at about 54 bhp each, for a total of 108 bhp. These are not as fast as the engines Don ran at Daytona. “The Daytona engines put out 61 bhp, but have a narrower power band and won’t pull the gear ratios on the streamliner,” Vesco says.

The engines are surprisingly close to standard roadster specifications, having “street” main bearings and even standard clutch plates (the road racing plates were discarded because they wouldn’t absorb the doubled horsepower). The crankshafts are near-standard.

Of course, the difference between the roadster you ride and the racing engine includes such things as beefier connecting rods, chrome-plated cylinder barrels with wilder port timing, expansion chambers, 34-mm Mikuni road racing carburetors and a close-ratio gearbox.

None of this is earthshaking o.r unattainable, and the sole difficulty lies in linking the two engines. For this, Vesco turned to Tabloc for specially made drive sprockets which are linked by double-row No. 38 chain. Vesco tried firing his engines 180 degrees apart and 90 degrees apart, but didn’t find much difference. For the record runs, he settled on 90 degrees apart, as the power impulses with this arrangement seem to provide better traction on the salt.

Most of the time, Vesco stops his machine with a single rear wheel hydraulic disc brake unit adapted from the front end of a Honda 750 Four. He has rearranged the transmission so that neutral is between 4th and 5th gears. After making a run through the traps, he whips in the clutch, cuts the ignition, and slips into neutral. He could slow

down on engine compression, but that would not allow him to check the plugs for carburetor jetting.

For awhile, he simply coasts. Because of the slippery aerodynamics of his shell, it takes him five miles to roll to a stop in neutral from 240 mph. Normally, he coasts three miles and then gradually applies the rear brake, to avoid overheating the unit, or causing momentary grabbing, which would skid the tire and produce an immediate blow-out. The parachute is strictly an emergency unit. In his first abortive record attempt during speed week this year, the parachute saved both him and the streamliner from a bending that might have deprived him of the record. The chute popped out when his rear tire blew at 250 mph.

“The blown tire pulled the chute cord. The machine was on its side before I had a chance to reach for the release. It all happened so fast,” Vesco says.

The chute kept the machine from spinning and flipping end over end. As Vesco was unhurt, and the damage to the streamliner was superficial, he was able to make repairs and reschedule another record run a few weeks later.

Vesco estimates that it would cost $16,000 for someone to have a streamliner built similar to his own. At least, he recovered part of his own outlay (less, because he could do much of the labor) in contingency awards: $5000 from Yamaha; $2000 from FE Plus, which he mixed 16:1 with his pump gasoline. He lost an undisclosed amount from Champion spark plugs; it was contingent on his record still standing at the end of 1970.

To Vesco, a road racer who has placed in the top five at Daytona, going straight at Bonneville provides just as much pleasure, on a sensual and satisfaction level, as the swerving sport.

He has been a regular at Bonneville since 195 1 and became a member of the 200 Mile-Per-Hour Club a few years back by setting a record in an Offenhauser-powered streamlined car.

“The satisfaction of Bonneville is that you’ve raced something that most people have never raced,” he says. “I knew all along that I could set a new record. 1 just had to get things working right. When 1 did it, some people were more impressed than I was.”

That’s the no-nonsense Vesco talking, the guy who created a record from common sense and experience. The simple functionality of his machine moved us to comment that it must take a good eye to build something like it.

He responded with a laugh that started slowly and built up: “Well, you have to roll ’em back a ways.”

As for those Harley Villains, he says “Boo,” naturally: “Just wait until next year.” {§]