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  1. 1 The Gyro-X is a two-wheeled, gyroscopically stabilised prototype car, built in 1967. Lane Motor Museum
  2. 2 It was the idea of the car stylist Alex Tremulis and the gyroscope expert Thomas Summers. Lane Motor Museum
  3. 3 Only one was ever built, by Gyro Transport Systems of Ridgecrest, California. Lane Motor Museum
  4. 4 The pitch: two wheels instead of four meant a smaller, lighter car that could use a smaller engine, a slim body that cut wind resistance, and half as many tyres to drag along the road. Lane Motor Museum
  5. 5 Its makers also argued that if everyone drove a gyro car, traffic lanes could be cut by half. Agency Impianti
  6. 6 It was promoted as reaching 125 mph on an 80 hp Mini Cooper S engine, and as swooping through 40-degree banked turns without tipping. Lane Motor Museum
  7. 7 It was first shown in “The Wonderful World of Wheels”, an exhibit at the 1967 New York International Auto Show. Lane Motor Museum
  8. 8 Octane gives the date of the New York unveiling as 1 April 1967. Octane, 2026
  9. 9 That September it was on the cover of Science and Mechanics magazine, billed as “impossible to skid or flip”. Lane Motor Museum
  10. 10 Octane’s verdict, in 2026: in reality, the prototype could do none of these things. Octane, 2026
  11. 11 Witnesses remembered that at high speeds, over 70 mph, it was unstable. Lane Motor Museum
  12. 12 “We had stabilisation problems in high-speed cornering that were never resolved,” Robert Poteet, who worked for the Summers Gyrocar Company, recalled in 2018. Octane, 2026
  13. 13 Period film, often quietly speeded up, never showed it moving much faster than walking pace. Octane, 2026
  14. 14 Gyro Transport Systems, Inc. went under around 1970, and the Gyro-X never went into production. Lane Motor Museum
  15. 15 Summers raised $750,000 for the venture. WIRED, 2017
  16. 16 Summers and Tremulis met in 1966. Octane, 2026
  17. 17 Summers had set up the Summers Gyroscope Company in 1946, and in 1961 he formed the Summers Gyrocar Company in Northridge, California, to develop gyro-stabilised vehicles. Octane, 2026
  18. 18 “Four wheels are ridiculous, three wheels are foolish, but two wheels are proper,” Summers explained in 1975. Octane, 2026
  19. 19 Before the Gyro-X, the Summers Gyrocar Company had built five small two-wheeled “mules” for the US Department of Agriculture, to carry loads slowly up mountain tracks. Octane, 2026
  20. 20 Summers applied for a US patent for a “gyro stabilized vehicle” on 31 March 1966, and it was granted on 12 November 1968. US patent 3,410,357
  21. 21 Tremulis was chief stylist of the Tucker 48, from 1947. Octane, 2026
  22. 22 He became chief of advanced styling at Ford in 1952, and left in 1963 to start his own design consultancy. Octane, 2026
  23. 23 A Ford colleague, Bob Thomas, remembered Tremulis tying a toy gyroscope from an army-surplus shop to a bar with two wheels in a line, then sending it across the studio, where it went straight as an arrow into the far wall. Octane, 2026
  24. 24 Those experiments led to the Ford Gyron, a two-wheeled two-seater concept car shown at the 1961 Detroit Auto Show. Octane, 2026
  25. 25 Ford’s management was unconvinced, and balked at the projected $135,000 cost of developing a working gyroscope. Octane, 2026
  26. 26 Tremulis’s interest in gyroscopes began in the Second World War, when he studied the gyroscopic guidance of a V2 rocket. Octane, 2026
  27. 27 Its tubular spaceframe and all-aluminium body were hand-built by the Los Angeles coachbuilder Troutman-Barnes. Octane, 2026
  28. 28 It had a pop-up headlight and four tail lights from a Chevrolet Corvair. Octane, 2026
  29. 29 The Lane Motor Museum describes a single 22-inch, hydraulically driven gyroscope. Lane Motor Museum
  30. 30 It was one vertical flywheel in a round housing just behind the front wheel. Octane gives it as 113 kg and 508 mm across. Octane, 2026
  31. 31 The flywheel spun at a steady speed, in the opposite direction to the front wheel, and a hydraulic ram could turn it left or right inside its housing. Octane, 2026
  32. 32 Turning a spinning flywheel produces a push at right angles to the turn, called gyroscopic precession. So turning the Gyro-X’s flywheel to the left made the car lean to the left, and turning it right made it lean right. Octane, 2026
  33. 33 A tilt sensor and control system kept adjusting the flywheel, like a tightrope walker with a pole, to hold the car upright. Fed with speed and steering, it could also lean the car into corners like a motorcyclist. Octane, 2026
  34. 34 The prototype used a BMC A-series engine in Mini Cooper S form. Drive went to the rear wheel by chain, through a four-speed Mini gearbox, and two hydraulic pumps powered the gyroscope and its controls. Octane, 2026
  35. 35 The museum lists the engine as a water-cooled 1,275 cc four-cylinder of 80 hp, mounted at the back and driving the rear wheel. Lane Motor Museum
  36. 36 Octane puts the Mini Cooper S engine at 76 bhp. Octane, 2026
  37. 37 For the production version, the plan was to drive the rear wheel hydraulically too, so that a coasting car could spin up the gyroscope: an early form of regenerative braking. Agency Impianti
  38. 38 The heavy flywheel spun at 3,000 rpm and stored a great deal of energy, which was a hazard in itself if something went wrong. Agency Impianti
  39. 39 When the car was shown to the motoring press, its gyroscopic control system had been taken out. Octane, 2026
  40. 40 In July 1970 Tremulis wrote that he was greatly disturbed to find the Gyro-X parked outside, uncovered and exposed to the weather and vandals. Lane Motor Museum
  41. 41 By January 1975 Summers had added a third wheel so that it could be licensed in California, where vehicles over 1,500 lb could not count as motorcycles. Lane Motor Museum
  42. 42 In 1978 it was on the cover of Summers’s booklet Gyrovehicles: a New Concept in Land Transportation, renamed the Gyroglide. Lane Motor Museum
  43. 43 In 1981 Tremulis wrote to Summers: “May 1981 be the year of the GYRO.” Lane Motor Museum
  44. 44 In July 1994 it changed hands to settle an unpaid loan. By then it was a Volkswagen-powered three-wheeler, and the gyroscope was long gone. Lane Motor Museum
  45. 45 The Houston collector Mark Brinker sold it to the Lane Motor Museum in Nashville in December 2011. Lane Motor Museum
  46. 46 Alex Tremulis’s nephew, Steve Tremulis, supplied a large archive of photographs, which guided the restoration. Octane, 2026
  47. 47 The aim, Jeff Lane told Octane, was to return the car as closely as possible to what it was in 1967. Octane, 2026
  48. 48 The restorer, Michael Hüby, ended up making almost everything needed to make it drive, from the chain drive and gear-change mechanism to the rear swing-arm, front suspension and brakes. Octane, 2026
  49. 49 The new gyroscope was built by Agency Impianti of Pisa, Italy, which makes gyroscopic stabilisers for large yachts. Octane, 2026
  50. 50 The new flywheel is a little smaller than the original: 104 kg and 434 mm across. Octane, 2026
  51. 51 At 3,000 rpm, Jeff Lane says, it holds as much energy as a 900 kg car at 30 mph, and it keeps spinning for two hours after it is switched off. Octane, 2026
  52. 52 The museum spent about $500,000 on the restoration, more than half of it on the gyroscope. WIRED, 2017
  53. 53 The restoration took six years. Octane, 2026
  54. 54 The restored car made its debut at the Pebble Beach Concours d’Elegance on 20 August 2017, 50 years after it was created. Agency Impianti
  55. 55 At Pebble Beach it won its class, American Dream Cars of the 1960s. WIRED, 2017
  56. 56 It also won the Dean Batchelor Trophy, for the most significant car related to hot rod heritage. Octane, 2026
  57. 57 In 2017 Lane admitted it did not yet work well above 25 mph: the controls were not precise enough to keep it stable at higher speeds. WIRED, 2017
  58. 58 “The gyro rocks a bit, like you’re sitting in a boat,” Jeff Lane said after his first drive. WIRED, 2017
  59. 59 By 2026 the team was running version 129 of the control software. Octane, 2026
  60. 60 Hüby has driven it in Nashville traffic and reached 55 mph on a private track. Octane, 2026
  61. 61 Starting it takes patience: the gyroscope must reach its working speed of 3,000 rpm, which takes about five minutes, before the parking wheels can be raised. Octane, 2026
  62. 62 Octane found that when everything goes smoothly it tracks straight, stays bolt upright and leans smoothly into corners, but gusts, bumps and sudden inputs bring twitches, lurches and wobbles. Octane, 2026
  63. 63 Hüby argues it should not be seen as a failure: regenerative braking, stability control and aerodynamics, all part of the Gyro-X idea, have since found their way into modern cars. Octane, 2026
  64. 64 Hagerty notes the original gyroscope was 22 inches across and the new one just 17 inches, with the same stabilising power. Hagerty, 2019
  65. 65 At Ford, Tremulis also encouraged a young designer, Jim Powers, to develop the idea that became the Ford Nucleon, an atomic-powered concept car. Hemmings (Kurt Ernst)
  66. 66 The Lane Motor Museum lists the Gyro-X’s engine as coming from a Mini Cooper S. Lane Motor Museum