Baby Bonnie: 1966-1973 Triumph 500cc T100R Daytona

By Staff
Updated on February 10, 2023
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courtesy Mecum Auctions
This 1969 Triumph T100R Daytona had less than 5,000 original miles on it. It sold at the 2022 Mecum Auction in Las Vegas for $14,300.
  • Claimed power: 39hp/41hp @ 7,400rpm
  • Top speed: 105mph (period test)
  • Engine: 490cc (69mm x 65.5 bore and stroke) air-cooled, OHV parallel twin
  • Transmission: Duplex chain primary, wet multiplate clutch, chain final drive
  • Weight: 356lb (dry)
  • Price then/now: $1,199 (1969)/$6,000-$15,000

Buddy Elmore’s victory in the 1966 Daytona 200 is the stuff of legend. Last-minute fixes to his tuned-to-the-max race bike put him at the back of the grid in 46th place. Regardless, by lap 22 he had fought his way through the field and stayed in the lead to the finish, setting a record speed of 96.58mph.

Elmore’s victory was remarkable in many other ways: his 1966 racer looked surprisingly close to the street 500 except for a new cylinder head with dual Amal GP carburetors, energy transfer ignition, oil cooler, one-gallon oil tank, racing exhaust and strengthened swingarm. Inside the engine, Triumph’s Doug Hele had worked his magic to unlock the engine’s potential, but reliability suffered; and in completing the full 200 miles, Elmore’s bike was more the exception than the rule. (Gary Nixon’s 1967 winning engine was strengthened with a full ball and roller main bearing crankshaft. That year, Elmore finished second.)

Moto marketers have never been shy about naming their machines for successful racing exploits and their locations. Think: Le Mans, Thruxton, Sebring, Monza, Manx, Bonneville, and — of course — Daytona. Winning the “Handlebar Derby” at the famous Florida course was perhaps the most prestigious victory of them all.

So when Triumph racked up three wins in the 1960s with their 500cc Tiger twin, (Don Burnett in ’62, Elmore ’66 and Nixon ’67), it was only a matter of time before the company capitalized on its successes. In late 1966, Triumph announced a new 500cc street sport bike based on the single-carb T100 Tiger but fitted with a new cylinder head featuring shallower valve angles, splayed intake ports to make room for twin Amal Monobloc carburetors, 9:1 compression, and Bonneville cams with larger followers: the T100R Daytona.

The drivetrain fitted in a new chassis with revised steering geometry and a stiffer swingarm mounting, but the rest of the bike was familiar Tiger territory. The 69mm x 65.5mm air-cooled OHV parallel twin’s heritage was easily traceable back to the 1937 Speed Twin, exposed pushrod tubes and all, though the transmission now shared its case with the engine. The new cylinder head topped the same iron cylinder barrels. The alloy rocker covers featured screw plugs providing access to check valve lash. Drive was by duplex primary chain to a 4-speed gearbox with gear position tell-tale. The Daytona ran on 3.25 x 19-inch front and 4:00 x 18-inch rear tires sharing the same 7-inch SLS drum brakes front and rear.

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