The Scene

THE SCENE

IVAN J. WAGAR

FEW people at Daytona realized that Roger Reiman and Goodyear were conducting tests with tubeless tires. Throughout all of practice, qualifying and the race, Roger ran without inner tubes of any kind. There is some speculation now that this might have been one of the reasons behind his very high qualifying lap of 149.080 mph. All seven Harley-Davidson engines were prepared in exactly the same manner, and all of the machines were very close in actual speeds during initial testing. Yet, not discounting the considerable tuning talents of Babe DeMay, Roger definitely had an edge over his stablemates during the high speed dash around the oval.

There are two weight saving advantages in the use of tubeless tires, and both affect handling to a high degree. First, the tire, or any part of the wheel or fork bottoms, is unsprung weight. The same is true at the rear, where approximately half the swinging arm weight, plus the wheel and its components, follow course undulations, and are not part of the suspended vehicle. Use of tubeless tires saves about 1.5 lb. per wheel, very little in the total weight of the machine, but very important if considered as unsprung weight. Second, the gyroscopic effect of a heavy, or light, tire is a major consideration in motorcycle racing. Factory Harley-Davidson racers were fitted with 18-in. wheels this year, and an additional 1.5 lb. on the circumference is very definitely a major problem in overall handling. Thus, considering these two important factors, the gains from elimination of inner tubes truly are worth the effort.

As previously stated, the tests were conducted by Goodyear and with Roger Reiman, not Harley-Davidson, though the factory had full knowledge and daily progress reports of what was happening. Before anyone rushes out to remove the inner tubes from his Goodyear tires, there is something he should know about standard tires, and what was different on Roger’s skins at Daytona. Normally, all tires have three or four minute awl punctures, so that air trapped between the tube and the inside of the tire can escape, and the outside of the tube mates faithfully with the inside of the tire and the rim. Goodyear’s racing chief, Mike Babich, was very careful to select some racing 18-in. tires from the Daytona batch before they were intentionally punctured in the normal manner.

Another problem that faces the private owner is the need for an absolutely perfect seal with a spoke wheel. Dunlop is building some special tires for Peter Williams to be used on his cast magnesium front wheel, but so far the English firm has made no announcement in regard to spoked rims, which present a leakage problem at every spoke nipple. Goodyear’s solution to the problem was to use gorp (a thick, non-hardening rubberish compound that no one likes to get on his hands) around the outside of the rim. Naturally the application of the gorp is very important to the ultimate seal, and must be done very carefully if the tire is to remain leak proof. In Roger’s case, and with an Amateur, who tried the scheme on the rear tire only, there were no problems whatever with leakage.

This is another good example of how racing improves the breed. Roger used absolutely standard rims-the same as all the other H-D riders-but, with the aid of a little foresight and imagination, was able to save 3 lb. where it really counted. Despite having to use higher pressures than when the tubes are fitted, Roger reported a smoother ride. No doubt this was due to the lower amount of work being accomplished by the suspension.

ALTHOUGH faced with hundreds of small jobs which must be accomplished during Daytona week, the CYCLE WORLD staff this year made a recording of Daytona Speed Week. Our cohort in this effort was the G & G Recording Service of New York, which has successfully made discs of various sports car events at Daytona. Several months before Daytona, when the subject first came up, CW was leery about competing against the English Stanley Scho field series, which CYCLE WORLD RECORDS currently sells. Trying to compare the sounds of basically standard AMA equip ment against Honda Sixes and Moto Guzzi V-8s was a little more than I personally could comprehend.

By Tuesday afternoon, however, when some of the tapes were available for playback, I was convinced that here was something better than any motorcycle race recording ever made before. The big Harleys and little Yamahas and previous winning Triumphs are all sounds which are never heard at the Isle of Man, or anywhere else.

American riders are the most colorful extroverts in the world. And personal interviews with Bobby Winters, Gary Nixon, Yvon du Hamel, Dick Hammer, Cal Rayborn, Dick O’Brien, Doug Heil, Tony Smith and the like will be worth more than the price of the disc.

More than 20 hours of tape have been recorded, in stereo, of the whole Daytona week. Months of editing will be required to chop the tapes down to a 40-odd minute disc. When all the work is finished, Daytona 1968 will join the Schofield series in CYCLE WORLD RECORDS. I am struggling very hard to keep my name at the top of the list for the first disc because, like it or not, Daytona is where it’s at, baby.

FOR all those readers who may be wondering why Yankee chose a 40-year-old design for their new machine let me assure them that the editor almost blew his mind when he saw his column last month. But as one office quip said, "Who reads the editor's column anyway?"