Yamaha XS Eleven

Yamaha XS Eleven [1]
Manufacturer Yamaha
Also called XS1100, XS11
Production 1978-1981
Class Superbike
Engine Air cooled,1101cc, 4s, 4c transverse, DOHC, carb. (4) Mikuni BS34II constant velocity air
Compression ratio 9.2:1
Top speed 129.4 mph (208 km/h)[2]
Power 95@8000 hp@rpm (claimed)
Torque 66.5@6500 lbs/ft@rpm (claimed)
Ignition type Transistorized, vacuum advance
Transmission 5 speeds, shaft and bevel gear
Brakes f. 2x298 mm (11.7 in) single piston calipher / r. 1x298 mm (11.7 in) single piston calipher[2]
Tires f. 3.5H19 Bridgestone / r. 4.5H17 Bridgestone
Rake, trail 20.5°/130 mm
Wheelbase 1,544 mm (60.8 in)
Dimensions W: 812 mm (32.0 in) (handlebar)
Seat height 820 mm (32.3 in)
Weight 603 lb (274 kg) (wet)
Fuel capacity 20 l (5.3 US gal)
Oil capacity 3.97 l (1.0 US gal)
Fuel consumption 37.9 mpg-US (16.1 km/l)
1979 Yamaha XS Eleven Standard

The Yamaha XS Eleven motorcycle, also called XS11 and XS1100, is a Japanese superbike produced from 1978 to 1981, powered by a air-cooled 1101.6cc 4-stroke, DOHC inline four-cylinder engine mounted transversely in a duplex cradle frame with swingarm rear suspension, shaft drive, and telescopic forks.[3]

Models

The XS Eleven made its debut in 1978 as the largest capacity Japanese superbike then in production. It featured dual front disc brakes, a rear disc brake, shaft drive and cast wheels. A "factory custom" styled XS Eleven Special was released alongside it in 1979. Both models were superseded by the 1982 XJ1100 Maxim which used an engine based very closely on the XS1100 unit. The XJ1100 Maxim was only built for one year, before being phased out. In Europe, the XS Eleven differed from the North American model by having a larger gas tank (6.3 US gallons vs. 5.3 US gallons), a lower handlebar and longer exhaust pipes. The European market also featured the 1.1 Sport (based on the Special model) and Martini (based on the original XS1100) versions. Both of these additional models were faired.

History

The XS Eleven was the first four-cylinder four-stroke motorcycle from Yamaha. It exploited well-proven technology, first used by Yamaha in their previously released XS 750 four-stroke triple. When the XS Eleven was introduced, it earned a reputation as a heavy, powerful bike. At the time of its release it was the most powerful production motorcycle money could buy. "Nobody gets far riding the XS11 before they become acquainted with the fact that it's strong; we had ridden ours over hundreds of open-road miles before going to the drag strip and knew it was a bullet."[4] Cycle Magazine had this to say of the Eleven: "...the XS is a Rolls Royce with a blown Chrysler Hemi motor..." The handling of the XS Eleven was not as well received. "When this behemoth of a motorcycle actually hits a corner at anything approaching interesting speeds then it takes a good deal of muscle to lay it down. While the Yamaha doesn't disgrace itself in corners (not as much as some Z1000s I have known, for example) it doesn't commend itself either."[5] However, in a comparison with the Kawasaki Z1300, another reviewer said the Yamaha "did everything better by a country mile".[6]

In 1979, Yamaha followed the growing trend of offering a "factory custom" version of the bike, called a "Special" by Yamaha. Pullback handlebars, a stepped seat, a smaller, fatter rear wheel, a smaller capacity tear-drop gas tank, fully adjustable suspension, and altered frame created a factory custom, forerunner of the modern cruiser. The XS Eleven Special sold well despite complaints about the poor ergonomics. "What that translates to is a bike with an awkward riding position but generally excellent road manners. In fact, most of the things that irritated this staff in the way the bike rode and handled could be traced to the handlebar, which, although certainly as trendy as disco dancing, was not what the ergonomics doctor ordered for precise, comfortable control."[7]

Racing

The XS Eleven enjoyed a series of wins and high placed finishes in the Australian motorcycle racing circuit between 1978 and 1981. Darryl Flack of Motor Sport Retro[8] wrote: "While the new CBX1000 and Suzuki were out and out sports bikes, the shaft-drive XS1100, affectionately called the “Xcessive’, was more of a muscle bike come tourer. Heavier than and not as fast as its rivals, the XS1100 did have one particular ability – winning races."

"In the lead up to the Six-Hour, the XS1100 had swept the Adelaide Three-Hour, the Perth Four-Hour and the Surfers Three-Hour. The unlikely XS1100 and Pitman Yamaha rider Greg Pretty had upstaged the biggest, baddest production bikes around, confounding everyone."

In a stunning upset against the Honda's much vaunted CBX1000, a stock XS1100E won the Australian Castrol 6 hour production race at Amaroo park in 1978, ridden by the Avon team of Roger Heyes and Jim Budd.

In the 1979 Castrol 6 hour, XS Elevens finished second (Greg Pretty, Jim Budd) third (Len Atlee, Gary Coleman) and fourth (Roger Heyes and D. Robbins)

In 1981, Greg Pretty and Gary Coleman piloted an XS Eleven fitted with a chain drive, custom swing arm and mildly modified engine to victory at the Coca Cola 800[9] at Oran Park.

Also in 1981, Greg Pretty was victorious at the Arai 500 at Bathurst on the same Pitman's prepped Yamaha XS1100.

The XS Eleven's very successful racing history and its period popularity belies its current reputation for poor handling.

British motorcycle journalist Roland Brown, in his book Superbikes of the Seventies, says "The Yamaha's lack of reputation gives it one advantage these days, though, in that a clean XS such as this one costs less than its more successful contemporary rivals - whose performance advantage, so crucial then, is far less important now. Two decades and more after its launch, maybe the XS1100's time has finally come."

The bike had a recorded stock quarter mile time of 12.02 s 1/4 mile @112.07 mph (180.4 km/h)

XS Eleven Venturer

In 1981 a touring version of the XS Eleven was produced. This model, dubbed the Venturer was equipped with a Windjammer like fairing similar to those made by the Vetter Fairing Company but branded by Yamaha. Venturers included matching trunk and hard bags. Additionally, the Venturer included a 6.3 gallon tank for increased range while touring.

See also

References

  1. ↑ YAMAHA XS1100. Motorcyclist. January 1978. p. 29.
  2. 1 2 "Yamaha XS eleven test", Cycle, p. 40, March 1980, archived from the original on 22 March 2010
  3. ↑ Doug Mitchel (January–February 2010). "Yamaha XS1100". Motorcycle Classics. Retrieved 2010-05-21.
  4. ↑ Cycle, January 1978
  5. ↑ SuperBike, April 1978
  6. ↑ http://www.realclassic.co.uk/kawa03110100.html
  7. ↑ Cycle Guide, February 1979
  8. ↑ Motor Sport Retro
  9. ↑ Coca Cola 800
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