Cycle World Round Up

CYCLE WORLD ROUND UP

It's a radial rage

Don't look now, but the age of radials is upon us—again. Twenty years ago, radial tires for automobiles were little more than foreign-made conversation pieces. Touted by their manufacturers as offering better handling and longer wear characteristics than conventional bias-ply tires, radials gradually grew more and more popular. Today, it’s hard to buy a new car that doesn’t come equipped with radials. And the same thing just might happen to motorcycles.

Before getting into why radiais seem to be the coming thing for motorcycles, a little tireology. Present motorcycle tires use bias-ply construction, which means, simply put, that the cords comprising the tire’s carcass are layered on top of one another at angles. It is this angularity of the cords that gives rigidity to the sidewalls. A radial tire’s cords, however, run straight across from bead to bead, perpendicular to the tire’s direction of rotation.

And that’s the “secret” of why radiais offer performance gains: With no cords crossing one another, there’s less internal friction and less heat generated by the flexing of the tire. Less heat means the tire will wear more slowly or that a softer tread compound can be used.

A radial tire can also be made lighter, which is bene ficial in two ways. Unsprung weight is decreased, allowing a bike's suspension to react more quickly; and tire inertia is lessened, which eases steer ing effort and, to a lesser degree, improves acceleration and braking performance.

The question is, if radiais are so good, why aren’t we all riding on them. The answer: handling problems. As we’ve just learned, radial tires have more flexible sidewalls than do bias-ply types, which explains the underinflated look that car radiais always have. And therein lies the advantages of radiais for automotive applications: That flexibility allows the tire’s wide tread to stay flat on the ground as the car's chassis “rolls” to the outside when going around corners. But the manner in which a motorcycle “leans” around corners involves an entirely different set of tire dynamics; and as a result, flexible sidewalls on a motorcycle tire cause what the engineers call “directional instability.” Translation: The bike goes straight when the rider wants to turn.

So motorcycle radial development was left to gather dust on a back shelf. That didn't bother too many people, because bias-ply tires were doing a pretty good job. Until recently. Today’s motorcycles, especially largedisplacement sportbikes, are able to go faster and handle better than most full-on racebikes could a few years back. Consequently, tires are taking a real pounding; ridden with vigor, a liter-class sportbike can make its tires eligible for the trash bin in less than 1500 miles.

This problem is what has prompted tire engineers to resurrect the radial concept for two-wheel applications. Their work has been concentrated on reducing sidewall flex, and so far, three methods have been used. One is to layer the cords at very slight angles, the result being a combination radial/bias tire that some manufacturers refer to as a “semi-radial.” Another solution is to build a true radial but add reinforcement in the form of extra rubber or cords—or both in the sidewalls. This reduces sidewall flex, but it also results in added weight, friction and heat, the very things a radial is supposed to reduce. >

The third solution is to use a true radial with no stiffeners but to make the sidewalls so short that they resist flex. Michelin, a pioneer of radiais for automotive use, has been working with Bimota, the Italian specialty-bike firm, in designing these low-sidewall radiais. What they’ve come up with are massively wide tires that have an extremely low profile. The tires’ aspect ratio—the ratio of tire height to tire width—is 60, compared with 80 or 90 on conventional sport tires. The sidewalls look to be only about an inch high, mandating the use of special 18-inch wheels instead of the original design’s 16-inchers so that ground clearance won’t be drastically reduced. Michelin also is supplying Team Honda’s GP roadrace effort with radiais. Freddie Spencer’s win at the Italian GP, in fact, was the first for a bike shod with radial tires.

Neither has Dunlop been asleep when it comes to radiais. The company recently ran a full-page advertisement in motorcycle magazines and a smaller ad in The Wall Street Journal proclaiming that Dunlop had “America’s first radial motorcycle tire.’’ And the ads also stated that the tires would be available “soon.” When asked how soon and what type of construction the tires would use, a Dunlop spokesman couldn't elaborate. “That’s something our competitors would love to know,” he said. Industry rumors, however, put the Dunlop’s introduction date somewhere in 1985, and the word is that the first model will be a touring tire, not a sportbike-type. When queried about the first-inAmerica claim, the spokesman hedged, saying only that the Dunlops were the first to be introduced in an advertisement to the American public.

Almost all the other tire companies admit to some level of involvement with motorcycle radiais. Metzeier showed a semi-radial prototype two years ago and is currently working with semis and true radiais. Pirelli also has a radial, one that, according to some reports, will be standard equipment on Laverda’s Corsa model and on Bimotas imported to the U.S. A Bridgestone radial is original equipment on the rear of the Honda VF1000R (a fully faired, more-powerful version of this country’s 1000 Interceptor) sold in Europe. Bridgestone claims that this is the first large-scale OEM application for motorcycle radiais. Honda even tested this same tire for its U.S. Interceptor, but racetrack tests indicated that the tread compound was too soft for such use and tended to make the tire overheat. Test riders reported good handling characteristics, though, and that for street use the tire would have been all right; but American Honda chose to wait until all the bugs are worked out rather than risk having the bike earn a bad reputation because of some tire-related problem. And one of Bridgestone’s Japanese competitors, Yokohama, has introduced a line of radial motorcycle tires it calls Gettars, although they’re sold only in Japan at this point. Yokohama’s claim is that the Gettar is the first Japanesemade radial tire available for replacement use.

So as you can see, there are a lot of claims being bandied about concerning radial tires on motorcycles. But who’s first with what type really isn’t important to anyone other than the tire manufacturers themselves. All that matters for the present is that no radial motorcycle tires are being sold in America, either as original equipment or as replacements. Chances are, though, that if and when radiais do become available here, most will actually be semi-radials, tires that will stretch the definition of the word radial, but that will be compatible with standard rims. If true radiais are used—and you can bet that at least one will show up they will appear only as standard equipment on a motorcycle with wheels designed expressly for that kind of tire.

Two greats gone

Motorcycling recently lost two of its more prominent personalities with the deaths of Earl Flanders and J.C. Agajanian.

Flanders died April 30th at his home in Sierra Madre, California, after a long battle with cancer. He is perhaps best remembered in recent years as referee for motorcycle speed records at the Bonneville Salt Flats and as AMA West Coast technical inspector; they were two jobs that Flanders held for many years and enjoyed doing in a career that spanned 60 years. Despite having retired from his business interests and other obligations two years ago, Flanders remained active in motorcycling right to the end at age 73.

Flanders’ early career as a motorcycle racer for a Pasadena shop was cut short when a judge “volunteered” the hell-raising youngster to five years in the Merchant Marines. After his time at sea, Flanders resumed his racing, primarily on the many speedway tracks that dotted Southern California in the Thirties. When World War II broke out, speedway stopped and Flanders went to work on defense projects as a machinist.

During this time, Flanders started making handlebars for his motorcycles, then for his friends’ bikes. This grew into the Flanders Co., an accessory firm that he founded after the war.

As the post-war economy boomed, Flanders’ business thrived. Tough times were to follow, however, when many of the motorcycle industry’s youthful customers were shipped off to fight the Korean War. After the conflict ended, business picked up, and Flanders became the West Coast distributor for NSU and BMW motorcycles. NSU collapsed in the Sixties and BMW’s U.S. importer bought back its franchise in 1971. In 1978, Flanders retired from the company and was succeeded by his oldest son,John

Aside from his business, Flanders will be best remembered for his organization of the motorcycle events at Bonneville’s annual Speed Week. Prior to his involvement in 1959, motorcycle record-setting was more or less a chaotic free-for-all. With Flanders came standards for equipment, safety gear and technical scrutiny, which helped make Bonneville a benchmark for performance achievements.

Flanders left Bonneville in 1976, and in early 1982 he retired from his tech-inspector position with the AMA; his health was beginning to fail, and the problem later was diagnosed as cancer. Flanders kept going, though, serving as president of a local motorcycling group, the Trailblazers. In late ’83 at the AMA awards banquet, Flanders received the prestigious Dud Perkins Award for his dedication to motorcycling.

Flanders is survived by his wife Fucille and his sons John, Bruce and Paul.

J.C. Agajanian died May 5th in Los Angeles, Califor nia, of complications from cancer. He was 71.

Agajanian “Aggie” to almost everyone—made most of his money in the garbage collection business, but his passion was for racing. Although he never raced, Agajanian was one of this country’s major promoters for both car and motorcycle racing. Motorcyclists will remember Agajanian as the man behind Ascot Park, America’s most famous flattrack course. He promoted the first Ascot half-mile National in 1959, and his company, Agajanian Enterprises, now runs three National events a year at the venerable Gardena, California, facility in addition to promoting the mile at Sacramento.

Agajanian, whose trademark white Stetson was buried with him, made an impact in car racing as well. For 36 years, including 1984, he sponsored entries in the Indianapolis 500, where he was called “The Dean of Race Car Owners.” Two of Agajanian’s cars won the coveted event.

Race announcer Roxy Rockwood, who years ago was talked into his job by Agajanian, recently wrote this of his friend: “He was a

remarkable man and a helluva guy. There will never be another like him. A tip of the Stetson one last time to an individual who really did write a lot of cycle racing history.”

Agajanian is survived by his wife Hazel Faye, daughter Joan, and sons Cary, J.C. Jr. and Chris.

— Rex Reese

Uh, we can see why

Move and more motorcyclists in Ireland are choosing to ride without insurance, a spokesman for the country's largest underwriting firm moaned recently.

“(And) the percentage goes up as insurance goes up,” said Richard Thornley of Norwich Union.

Understandable.

Holy hype, Batman!

Afotorcycle collectors, get ready to kick yourselves. You missed your chance to own one of the truly significant motorcycles of all time: the Batcycle.

This sidecar-equipped creation, used in the celebrated TV series Batman, was part of the Cars of the Stars collection auctioned off recently in Chicago. Based loosely on a 1960s Yamaha, the Batcycle was the work of famed custom-car builder George Barris, also responsible for such works of art as In Ireland, the average 24year-old owner of a 500cc bike has to pay yearly premiums totalling about $ 1 260.

Bike video offered for loan

A new, 40-minute video cassette The Fun of Motorcycling is being offered on loan to motorcycle clubs.

The video program, produced by Spectro Oils, profiles three popular annual riding events: the Retread Motorcycle Club’s foliage ride, one of the Thursday New England woods rides organized by Dick Bettencourt, and a national motocross competition at Pepperel, Massachusetts.

The Fun of Motorcycling, on VHS-format cassettes, is the Batmobile, and the coffin dragster used in The Munsters TV show.

Apparently, the sidecar is actually a detachable go-kart, so that Batman’s sidekick, Robin, could “shoot out of the Batcycle . . . when necessary to pursue villains,” as the auction’s press release says.

If news that the Batcycle won’t be taking up residence next to your Norton International or BSA Gold Star is almost too much to bear, then don’t read on. Because also offered for sale was Evel Knievel’s very own HarleyDavidson XR750 jump bike. available free of charge from Spectro. For information, contact George Petetin, Inter national Lubricants, Box 209 Route 7, Brookfield, CT. 06804. Phone (203) 7751291.

007: License to crash

ICeen-eyed movie-goers may have spotted the Yamaha 650 Turbo underneath all the high-tech trappings in the recent James Bond movie, Never Say Never Again.

Especially keen-eyed movie-goers may have noticed that the Turbo was exchanged for a dressed-up XT550 for some of the stunts.

But what no one saw, were the five Turbos and five XTs that were crashed and damaged beyond repair. Knievel’s motorcycle is painted red, white and blue, and the gas tank is decorated with a caricature of E.K. himself, for “good luck,” notes the press release. The bike’s most fantastic feature, though, is its top speed, claimed in the press release to be 165 mph.

Geez. Perhaps it’s not too late for Harley-Davidson’s dirt-track team to find the new owner of Knievel’s bike, buy that 165-mph beauty, slap some numbers on it and get ready in time for the next mile National. Put a stop to those pesky, 130-mph Hondas once and for all.