Early ATVs were 3 wheelers

The  ATV has a 40 years history and the first twenty years were dominated by three wheelers. The early ATV history can as well be called history of Honda  ATVs   as  other manufacturers who joined the game more than ten years later.

 The 1960s: Prototyping the ATC.  
 
If necessity was the mother of the first ATV, Honda engineer Osamu Takeuchi was its father. In 1967,American Honda asked  Honda R&D Ltd. for a new product dealers could sell when motorcycle sales cooled off in the winter.

Forget the proverbial blank sheet of paper. Takeuchi started in the shop with a head full of ideas and an eclectic assortment of components. Two, three, four, five and even six-wheeled configurations were examined, but the three-wheel concept delivered the best combination for the machine's intended mission. It dealt with snow, mud and assorted slippery conditions a two-wheeler couldn't, while providing more maneuverability than other configurations.

 
 In the early stages, a Honda ST70 motorcycle gave up its 70cc four-stroke single-cylinder engine for the cause, along with assorted chassis parts... The biggest challenge would be finding a tire capable of getting a grip on soft, changeable terrain such as snow, sand and mud. Two wheels, three wheels, four wheels or more? Motorcycle tires weren't an option.

 
The design process quickened when Takeuchi received an American invention called the "Amphi-Cat? that rolled on six 20-inch low-pressure, high-flotation balloon tires. The light bulb went on. Revamping his ST70-based prototype to accept the new low-pressure rolling stock, he went to work on his own tire design, ending up with a 22-inch design inflated to 2.2 psi. With the tire dilemma solved, the 70cc engine lacked the muscle necessary to push a full-sized rider through snow or mud. A 90cc engine running through a special dual-range four-speed gearbox added the requisite flexibility over varied terrain.
 
The next phase of development was optimizing the chassis to match the new engine and tires. Testing over rough roads, sand hills and slopes as steep as 35-degrees gradually established chassis dimensions effective for recreational riding as well as agricultural work. Laid out in the shape of an isosceles triangle with the footpegs located outside the triangle to optimize control, the ATC design was unique enough to let Takeuchi patent the arrangement.

Exhaustive testing brought other lessons to light as well. Using a thumb throttle instead of the typical motorcycle twist grip let riders shift their weight for optimal vehicle maneuverability while maintaining precise throttle control. A rear differential was considered, but discarded when a live axle performed better. Though suspension is an integral part of the modern ATV, Takeuchi's original balloon tires soaked up rough terrain best by themselves. Exerting less pressure on soft or sensitive terrain than the average human foot, those tires let the vehicle go places others couldn't, leaving little or no evidence of their passing--an advantage that looms large in hundreds of modern ATV applications.


The 1970s: The World's First ATC

Officially introduced to America in 1970, the US 90 sent its 7 horsepower through a dual-range four-speed gearbox with automatic clutch, and sold for $595. It was renamed the ATC90 later that year as Honda trademarked the ATC name. The ATC70 gave younger riders a scaled-down version of the fat-tire experience. And by the end of the decade, requests for more power turned the original ATC90 into the ATC110 in 1979. The ATC was as evolutionary as it was revolutionary from the beginning.


Though it was primarily a recreational vehicle through the '70s, farmers were beginning to see the ATC as a tool to make their lives easier. Engineers followed their machines into the field, gathering data to guide the machine's natural adaptation to a rapidly growing market. The ATC was as capable at labor as at leisure, and America was catching on.

  Moving into the '80s, the two arenas looming largest in the ATV lexicon were utility Introduced in 1980, the ATC185 was popular among utility users. Rolling on larger, 25-inch tires that afforded improved traction, the 185 featured a five-speed transmission and automatic clutch and a 180cc four-stroke single-cylinder engine that was considerably more powerful as well. Though designed to split its duties more or less equally between work and play, the 185 set the stage for Honda's first purpose-built utility ATV two years later.

The 1982 ATC200E, a.k.a. "Big Red", had more of everything necessary to get a host of jobs done. Its 192cc engine and five-speed dual-range gearbox cranked out more power, especially low in the rev band, to make chores such as towing, spraying, seeding and fertilizing easier. An electric starter in addition to the standard recoil system made starting the day as easy as pushing a button. Dual racks and a 9.2-liter storage box made carrying tools, hay bales, fencing and other agricultural essentials easier. A new sealed rear drum brake survived the muddy fields and water crossings, and telescopic fork front suspension made a day in the saddle that much more comfortable. Big Red added a reverse gear in 1984, and its drive chain was replaced with shaft drive for extra durability and less maintenance.

 
Yamaha, Suzuki & Kawasaki started ATV manufacture around 1980. In 1982, Suzuki took the lead in the hot new market for all-terrain vehicles by introducing the first four-wheel ATV and other companies followed it.  Interesting fact is Honda had the patent on three-wheelers. So Suzuki was challenged to think outside the box. Its chief designer Aki Goto took this as a challenge and result was first four wheeler ATV.

Later the safety factors made all companies to shift to four wheel ATVs   and  3-wheel models ended production in 1987