Learn how the Yamaha XS750 took a different approach to control the U.S. touring bike market while outperforming the Laverda and Triumph competition.
1976-1979 Yamaha XS750 Specs
- Years produced: 1976-1979
- Claimed power: 64hp @ 7,500rpm (69hp @ 8,400rpm from 1978)
- Top speed: 106mph
- Engine: 747cc (68mm x 68.6mm bore andstroke) air-cooled, DOHC triple, 9.5:1 compression
- Transmission: Hy-Vo chain primary, wet multiplate clutch, 5-speed gearbox, shaft final drive
- Weight (curb): 550lb (249kg)
- MPG: 46
- Price then/now: $2,240 (1976)/$2,000-$7,000
By the late-1960s, the race for motorcycle supremacy in the U.S., the world’s biggest market, was all about performance. It was equally clear that the day of the dominance of parallel twins was over. As power output and swept volume increased, so did vibration — and buyers’ frustrations at broken license plates, shattered headlight bulbs and loose fillings! Except for Norton and the cushion-framed Commando, the quest for power would point to more cylinders. Announced just months before the four-pot Honda 750, BSA-Triumph launched its three-cylinder Trident and Rocket 3.
So what was the way forward? Triples or fours? Arguably, the quads won the day: the basic design being the template for the air-cooled, DOHC “Universal Japanese Motorcycle.” But three inspired designs showed that the alternative strategy might be worth consideration.
The Trident came first. Bert Hopwood, Doug Hele and Jack Wickes had completed a prototype as early as 1965. Looking like a slightly bulky Bonneville unit, the engine was derived from Triumph’s unit-construction 500cc twin by adding an extra cylinder. But for management procrastination, it could have scooped Big Red by four years — in spite of lacking electric start, a disc brake and a fifth gear. By 1975, the Trident had gained all three, but by then it was too late.
Laverda had gained an enviable reputation for robustness with the 750 SF-range twins and SFC750 endurance racers. And like his British competitors, Massimo Laverda concluded that for more power, an extra cylinder was needed. A first prototype was duly presented in September 1969, with the pre-production triple — now with dual overhead cams — shown at the 1971 Milan show.
Though born of the same need, the Laverda and Triumph were very different, a function of their design history and end constraints. The Trident used a one-piece crankshaft with plain big end bearings, gear-driven camshafts with pushrods and rockers, dry sump and single-plate clutch. The Laverda’s chain driven dual overhead camshafts actuated the valves by shim-under-bucket followers. A wet sump/primary cooled the multiplate clutch.
Worth noting are the two engine architectures: The Trident’s crankshaft was forged with the big ends in the same plane as the cranks, then heated and twisted to give 120-degree throws; Massimo’s built-up crank was also first set at 120-degrees, but excessive rocking-couple vibration led to the production 3C having 180-degree throws, and the characteristic 1-2-3-miss firing order.
Enter the XS750. By 1976, Yamaha had been building 4-stoke twins for six years, enjoying some success with the XS-1/650 and 750, while suffering relative disappointment with the TX750 and TX500. Forsaking the four-piston layout of its domestic competitors, Yamaha designed an in-line triple with 120-degree throws, dual overhead camshafts with shaft final drive via two bevel gears and CV (constant velocity) joints. These were more expensive than Cardan-type universal joints but were unaffected by rear suspension travel.
With a claimed 64 horsepower and a top speed of 106mph, the Yamaha couldn’t come close to the Kawi Z1, but neither was it intended to. The XS750 was aimed at the touring market for which its smooth-running engine, effective triple-disc brakes, competent handling, supple suspension (for the time) and sophisticated drivetrain were ideally suited. Add conveniences like auto-cancelling turn signals, vacuum-operated petcock, and a headlight failure tell-tale on the dash.
Cycle magazine chose the XS750 as one of the ten best motorcycles they tested in 1976, while Cycle World called it the “flagship of its class” and a “bargain BMW,” while the U.K.’s Motorcycle News picked it as their “Machine of the Year” in 1977.
But it wasn’t all beer and skittles. The XS had a habit of jumping from second to neutral under acceleration (a factory kit alleviated but didn’t cure the problem) and the vacuum petcocks were known to fail, flooding the crankcase.
1978 brought the XS750E with more power, lower overall gearing and a 3-into-2 exhaust system that negated the glorious howl of the earlier model’s 3-into-1. 1979 introduced the EPA-friendly XS850, which produced less power than the 45-incher but complied with noise and environmental requirements. But the final closing of the coffin lid was the replacement of the triples with the mighty four-cylinder XS1100 in 1979. MC
Contenders: More Alternatives to the XS750
1974-1976 Laverda 3C/3CL
- Claimed power: 80hp @ 7,250rpm
- Top speed: 123mph
- Engine: 981cc (75mm x 74mm bore and stroke) air-cooled, DOHC triple; compression 9:1
- Transmission: Triplex chain primary, wet multiplate clutch, 5-speed gearbox, chain final drive
- Weight (wet): 543lb (246kg)
- MPG: 35-40
- Price then/now: $3,900/$6,000-$15,000
Although Laverda showed a 1,000cc SOHC 3-cylinder bike at the 1969 Milan show, it was another three years before the specification was finalized: a 180-degree crankshaft engine with chain driven dual overhead cams, three Dell’Orto pumper carbs, Borrani rims with Laverda drum brakes, and a sturdy steel tube frame. Over the next three years, FLAM alloy wheels and triple Brembo disc brakes replaced the wire wheels and the Ceriani fork was swapped for a Marzocchi. And working with U.K. distributor Slater Brothers, Laverda produced a tuned version: the mighty Jota, with 90 horsepower and a top speed of more than 135mph making it the fastest production bike at that time.
Cycle magazine snagged a ride on one of the first 1000s and called Laverda’s new triple “brilliant,” praising especially its handling and its engine, “producing thunderous horsepower over a broad range and without a trace of temperament.”
Cycle was only slightly less gushing about the production 3C of 1974: they found it to be “a better 90mph cruiser than anything this side of a Honda GL1000 or a BMW R90S.” On the downside, Cycle also noted the 3C’s handling was less stable than the first 1000, due, they presumed, to a steering angle change from 29 to 26 degrees.
The 3CL (and the Jarama, a U.S.-market specific version) continued alongside the Jota to 1980.
1975-1976 Triumph T160 Trident
- Claimed power: 58hp @ 7,250rpm
- Top speed: 115mph
- Engine: 740cc (67mm x 70mm bore and stroke) air-cooled, OHV triple; compression 9.5:1
- Transmission: Chain primary, single-plate clutch, 5-speed gearbox, chain final drive
- Weight (dry): 502lb (228kg)
- MPG: 37
- Price then/now: $2,870/$7,000-$13,000
Though the T150 Trident had gained five gears in 1972 and a front disc brake in ’73, it took until 1975 for electric start and a rear disc (and a switch to foot shift left and brake right) to arrive. The T160 was now a sophisticated and capable tourer — except that the electric leg and other mod cons added some 40 pounds.
For the T160, parent company Norton-Villiers-Triumph adopted a forward inclined engine similar to that used in the BSA Rocket 3 and the Triumph X75 Hurricane, but in a new frame with better ground clearance. The black-cap “silencers” were shared with the Norton Commando (which also went electric in 1975).
Roland Brown tested and reviewed a T160 for Motorcycle Classics in 2006 and found that although the bike felt heavy and ponderous at low speeds, the high-end handling was “impressive,” the suspension was “excellent” and the brakes slowed the bike “reasonably well.”
“Revved hard the Trident is a thrilling bike to ride, its top end acceleration matching most bikes on the road in 1975.”
Brown concluded that: “The Trident has a lovely, rev-happy feel that encourages you to keep it spinning. And although its 58hp maximum seems moderate now, the Triumph was and still is capable of covering large distances at speeds well in excess of the legal limit.”
