How Dick Mann And BSA Won Daytona | Cycle World
Douglas MacRae

How Dick Mann And BSA Won Daytona

The Daytona 200 was a race of attrition, and Dick Mann knew how to win

During Dick Mann’s racing career, people said: “He sure is lucky. Just when you think someone’s got the race sewn up, he comes from nowhere to win it.”

The truth was that Mann understood what machines could and could not do. He managed his resources wisely. In 1970, he won the Daytona 200 on a Honda CB750-based racer. Mike Hailwood on a BSA Triple was out on lap eight with center-piston failure. Cal Rayborn’s iron XR Harley-Davidson failed a valve. Ron Grant’s Suzuki seized, and then Gary Nixon’s Triumph Triple failed, as ­Hailwood’s had. And there was Mann, first at the finish.

AMA racing’s rules had for years pitted 750cc Harley side-valve four-strokes against everyone else’s 500cc overhead valve (OHV) models and two-strokes. Then, in 1968, Harley-Davidson brought innovations to Daytona that rubbed out the Triumphs that had won the 200 in 1966 and ’67, relegating them to sixth in 1968 and ninth a year later.

Dick Mann’s BSA Triple

Dick Mann’s BSA Triple was far from a production racer.

Douglas MacRae

Crisis was the agenda that December for AMA’s first Competition Congress. Triumph proposed 650cc OHV for all comers (because 650 Bonnevilles were what they had on hand), then Harley raised the bid 100cc to 750—and the measure passed. For two-strokes, the limit would remain 500.

This unleashed new and potent market forces into AMA racing. American riders had demanded more-powerful bikes every year since the end of World War II, and in 1969, Honda and Triumph/BSA raised the ante with the CB750 Four and 750 Triples based on Triumph’s already proven 500. The history of this Triple was much older. In 1960, the designer of the original Speed Twin of 1937, Edward Turner, authored an ominous report on his trip to Japan: Ultramodern production techniques stood ready to dominate motorcycling’s future. As early as 1948, designer Bert Hopwood had explored modular design, a “means of producing a range of machines, from small to large, with as many common components as possible.” Had this been adopted, the results might have been a 250 Single, 500 Twin, 750 Triple, and a 1,000cc Four. Britain instead stuck with steady growth, of displacement and vibration, in its existing Twins—until the Triple.

The Triple began with lessons learned from the ­250-cylinder size of the refined 500 Twin. Like it, the ­Triple’s design would conserve cost and tooling by remaining a two-valve pushrods-and-rockers engine. Engineers separated the Twin’s two near-hemispherical case halves and placed between them a casting supporting the Triple crank’s center crank throw between two plain insert main bearings. The result was a bodge, and it was heavy. A single, separate finned aluminum cylinder ­casting carried austenitic iron liners, topped by a unit cylinder head whose top cooling fins were walled in by its two full-width rocker boxes. Their cooling was just adequate for the streetbike duty cycle.

special chassis, suspension, and brakes

AMA rules allowed for a special chassis, suspension, and brakes to keep Triumph/BSA competitive.

Douglas MacRae

Unleashed by the AMA, the four-stroke factories had little time to develop Daytona-eligible racebikes. In an intensive crash program, Harley designed and manufactured 200 new iron XR750s. The threatening spoiler was Yamaha, whose little 350cc air-cooled two-stroke twins had finished second and third in the Daytona 200 in 1968, and third, fifth, seventh, and eighth in 1969.

In late November 1969, Triumph contested the 1970 Daytona 200. What could it accomplish in three frantic months?

New AMA rules allowed approval of special racing chassis, suspension, and brakes, so the new Triple engine was modified in the usual ways and placed in a Rob North twin-loop steel-tube chassis. Front suspension was telescopic, with a four-shoe 250mm Fontana drum brake and a small disc rear.

1-3/16-inch Amal GP carburetors

Feeding the Triple are 1-3/16-inch Amal GP carburetors.

Douglas MacRae

The Triple began with lessons learned from the ­250-cylinder size of the refined 500 Twin. Like it, the ­Triple’s design would conserve cost and tooling by remaining a two-valve pushrods-and-rockers engine. Engineers separated the Twin’s two near-hemispherical case halves and placed between them a casting supporting the Triple crank’s center crank throw between two plain insert main bearings. The result was a bodge, and it was heavy. A single, separate finned aluminum cylinder ­casting carried austenitic iron liners, topped by a unit cylinder head whose top cooling fins were walled in by its two full-width rocker boxes. Their cooling was just adequate for the streetbike duty cycle.

These were factory bikes, not production racers anyone could buy at a dealer.

THE 1970 DAYTONA 200

This 200 was a race of attrition: Only 16 of the 98 starters finished. Mann’s thoughtfully ridden CB750 Four was the only Honda running at the end. Of the six factory Triumph/BSA Triples entered, three finished second, third, and 12th. Gary Nixon had led on a Trident until 110 miles, but his No. 2 piston holed. Although there was talk of overheating caused by a too-small cooling air opening in the fairing, at least two other possible causes existed: 1) spark timing scatter caused by motions of the exhaust camshaft that carried the ignition breaker cam; or 2) fuel-feed irregularities causing the team to later replace Amal GP carbs and their remote float with integral-float Amal Concentric carbs (introduced in 1967).

Harley’s hot-running iron XRs detonated and failed ­pistons despite drastic lowering of compression ratio. Their best finish was nowhere—unless you count Walt Fulton Jr. in sixth on an “obsolete” KR side-valve.

The Triumphs in second (Gene Romero was closing on Mann) and third looked promising, but at their heels was Armageddon—the two-stroke threat of Yvon DuHamel’s tiny 350 Yamaha in fourth and the Suzuki 500 twin of New Zealander Geoff Perry fifth. Kawasaki was still a bit player.

Team Obsolete

Team Obsolete recently returned the Triple to 1971 specification.

Douglas MacRae

THE 1971 DAYTONA 200

Ten factory Triples were entered for the 1971 200—five BSAs and five Triumphs. Of these, four were updated 1971 machines. Honda did not enter.

New “lowboy” chassis moved the engine forward 40mm, lowered the steering-head 2 inches, and increased rake 2 degrees to 28. Longer swingarms kept wheelbase constant. Fuel-tank tops were lowered. The oil cooler was raised into the fairing nose from its previous place in front of the cylinder head, now served by the famed “letterbox” chin air inlet. Shortened and wider-spaced fork legs allowed the use of dual Lockheed discs and calipers up front, with the option of reddish, hard-coated Pagehiln aluminum discs. Ignition-timing scatter was reduced by carrying the contact-breaker cam in its own bearings, driven by a quill shaft from inside the exhaust cam. Engine development raised power to figures given as either 81 or 84 hp at 8,250 rpm.

Dick Mann, the 1970 200 winner, was assigned one of the 1971 BSAs. After riding it and being told it was good to 8,250 rpm, he privately decided it felt more like 7,800. Offered the trick coated-aluminum brake discs, Mann chose iron. Ditto with titanium axles: Mann asked for the stiffer steel ones.

Understanding ­mechanical limits

Mann’s ability to win, on this machine and others, stemmed from his understanding of ­mechanical limits.

Douglas MacRae

Triumph/BSA at Daytona in 1971 was factory racing on a grand scale—riders, mechanics, and company supernumeraries all in hotels, eating in restaurants, and running up rental-car bills. Where were the booming sales to justify this outlay? BSA closed in 1973, and Triumph became part of the temporary NVT combine before passing into history as well.

In the race itself, Dick Mann did it again, staying with the lead group while conserving himself and his machine. Early drama and tragedy included Gary Fisher’s short-lived lead on a privately entered Honda, and the fatal crash of Rusty Bradley. On lap 15, Hailwood was out with visible torching from the exhaust—a valve failure. Twenty-seven laps later, Paul Smart’s machine expired from the same cause. Mann raced as slowly to the checkered flag as Gene Romero’s advance behind him permitted. Mann’s second 200 win had been another well-judged performance.

the Triple

A heavy handful, the Triple required patience.

Douglas MacRae

As Mann’s contract with the importer continued, in mid-1972, the Rob North frame was replaced with one made by Wenco, a California fabricator, having a ­1-degree-steeper steering head and lighter weight. Mann rode this frame until his ride ended with the 1973 season. Teammates Romero and Scott were also provided with Wenco chassis.

When BSA closed, the BSA’s engine with its ­characteristic forward-sloping cylinders was renumbered as TRX7501 to conform to the Triumph numbering scheme as a “Hurricane.”

TR=Triumph
X75=Hurricane
01=this unit

David Roper

David Roper rode the recently restored bike at Millville.

Douglas MacRae

In the words of present owner Rob Iannucci of Team Obsolete: “The bike had languished at Triumph/BSA’s ­Duarte offices since Dick parked it at the end of 1973.” Les Edwards of Cycle Imports in San Jose, California, bought the bike, reselling it to Iannucci in 1977.

“It arrived in New York with hard tires and rancid ­Castrol R bean oil,” Iannucci says. Its second career began with Iannucci’s crashing it at a Bridgehampton, New York, club race. Thereafter it would be raced a remarkable 94 more times, 1977 to 2002. Engine and chassis development continued. Three basic changes made the greatest difference. First, the original “strange” gearbox ratios were replaced by a normal racing gearset. Second, a belt primary drive and Newby clutch saved 22 pounds. And finally, the Daytona-only 18-tooth front sprocket was replaced by a 17-toother. More than 20 other changes were made as well, as if Triumph’s development program had never ended. A great deal was learned in the process.

The machine has recently been returned to its 1971 condition, after which its usual rider, David Roper, rode it during the MotoAmerica weekend at Millville, New Jersey, this past fall. Roper’s comment upon completing his laps was: “I really have to respect anyone who could go 200 miles on this bike at racing speed. It’s really heavy and takes all my strength to make it turn.”

Dick Mann, schooled in an era when if you didn’t finish in the money you didn’t eat, knew how to make it happen.