Thor (motorcycles)

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Thor Moto cycle and Bicycle Company
FateSales stopped in 1920
Products Motorcycles

Thor was an American manufacturer of motorcycles and motorcycle parts especially engines, founded in 1901 in Aurora, Illinois. [1] From 1901 to about 1907 it made engines under license for Indian motorcycles of Connecticut, which Thor was also allowed to sell on the open market. Thor also sold a large variety of parts and when the agreement finally ended, entered the motorcycle market on its own selling complete bikes until about 1920. Some of its success were supplying engines to many motorcycle manufactures of the period, some record setting bikes in the early 1910s, and V-Twin engine with automatic valves.

Motorcycle Two- or three-wheeled motor vehicle

A motorcycle, often called a bike, motorbike, or cycle, is a two- or three-wheeled motor vehicle. Motorcycle design varies greatly to suit a range of different purposes: long distance travel, commuting, cruising, sport including racing, and off-road riding. Motorcycling is riding a motorcycle and related social activity such as joining a motorcycle club and attending motorcycle rallies.

Aurora, Illinois City in Illinois, United States

Aurora, a suburb of Chicago, is a city in DuPage, Kane, Kendall, and Will counties in the U.S. state of Illinois. Located primarily in DuPage and Kane counties, it is an outer suburb of Chicago and the second most populous city in the state, and the 115th most populous city in the country. The population was 197,899 at the 2010 census, and was estimated to have increased to 200,965 by 2017.


Although Thor motorcycles ceased production, it continued as a brand of household appliances by the parent Aurora Automatic Machinery Company which survived. Aurora Automatic Machinery Company had previously made cast metal parts in the late 1800s including bicycle parts.


Thor made engines for Indian from 1901 to 1907 when they introduced their own cycle; before then they only made engines and parts for other makers. [2] In 1910 Thor introduced a V-Twin engine, and mounted one cylinder straight up unlike in the more V shape that became common later in the century. [2] By 1913 they had developed a more advanced larger displacement engine and it was mounted with both cylinders at angles, in the typical V-shape. [3]

Thor stopped making motorcycle engines in 1916, and production dwindled in the late 1910s. [4]


Thor was the motorcycle marque of Aurora Automatic Machinery Company, which produced motorcycle engines for Indian motorcycles and went on to produce its own line of motorized bicycles in the early 1900s. [5] Aurora holds a special place in transportation history, employing Oscar Hedstrom, Al Crocker, and Bill Ottoway, famous for Indian motorcycles, Crocker Motorcycles, and Harley-Davidson respectively at one time or another. [4] Aurora started in 1886 as a machine shop and is known for making parts for bicycles in its early period. [6]

Oscar Hedstrom motorcycle designer

Oscar Hedstrom was a co-founder of the Indian Motocycle Manufacturing Company.

Indian Motocycle Manufacturing Company motorcycle manufacturer

Indian is an American brand of motorcycles originally produced from 1901 to 1953 in Springfield, Massachusetts, United States. Hendee Manufacturing Company initially produced the motorcycles, but the name was changed to the Indian Motocycle Manufacturing Company in 1923.

The Crocker Motorcycle Company is an American manufacturer, based in Los Angeles, California, of single-cylinder speedway racing motorcycles from 1932, powerful V-twin road motorcycles from 1936, and the "Scootabout," one of the first modern styled motor scooters, in the late 1930s. Production ceased in 1942. In 1999 Crocker Motorcycle Company was resurrected to manufacture authentic OEM replacement parts and now produces complete Small and Big Tank Crockers in southern California, following the original specifications. Michael Schacht is Crocker Motorcycle company President.

In 1901 Oscar Hedstrom worked with Aurora to make engines for Indian motorcycles, and by 1902 they had made 150 motors for Indian. [6] As part of their agreement Aurora was allowed to sell the motors to other parties and pay Indian a royalty. [6] Aurora also continued to make other bike parts but not a complete bike. [6] Finally Indian started producing their own parts and Aurora then went on to produce their own complete motorcycle known as Thor motorcycles. [6] The agreement between the two companies expired in 1907. Before that time, Thor did not make complete bikes and Indian used the Thor manufactured engines of Hedstrom's design. [7] After the split Thor began to innovate new features and this included the F-head engine, a V-twin engine, and automatic (aka mechanical) valves on the engine. [7]

In 1908 Thor achieved automatic intake valves on their engine and offered many typical options for the day. [8] During this time there was options like battery ignition and belt drive. [6] In 1913 Thor offered a Schebler carburetor on its 1200 cc twin. [9] Thor also used updraft carburetors on their engines. [9] In 1916 they offered a 3-speed transmission on their cycle. [6] Another option was an acetylene lamps for light. [10]

Updraft carburetor A component of the engine that mixes air and fuel together in which air enters at the bottom and exits at the top to go to the engine.

Updraft carburetor is a type of carburetor, which is a component of engines that mixes air and fuel together, and in this type the air enters at the bottom and exits at the top to go to the engine. An updraft carburetor was the first type of carburetor in common use.

A Thor motorcycle was used in the 1913 Charlie Chaplin film (18 minutes long) Mabel at the Wheel. [11]

Thor stopped making motorcycle engines in 1916, and production dwindled in the late 1910s. [4] In the early 1910s sales began to decline, and one of the factors may have been the rise of the Ford Model T. [10]

An example of a Thor product was the Model 13U, which had an overall blue color scheme with white tires and a 7-horsepower twin cylinder internal combustion engine. [12] One of the four surviving Thor Model 13U is at the National Motorcycle Museum in Iowa, USA. [10]


Two people on motorized bicycles race on a board track in 1911. 1911boardtrackracing.jpg
Two people on motorized bicycles race on a board track in 1911.

Thor hired William Ottaway in 1909, and he led Thor to success in motorcycle racing during his tenure until he left the company in 1913. [13] Ottaway was noted for his ability to tune engines and Thor set national records with Thor bikes. [14] At this time much of the racing was on dirt tracks or tracks of wooden boards, and racing was noted as important for of recognition on the motorcycle market. [14] [15] (see also Board track racing)

An example of a Thor racing bike was the 1912 Thor Board Track Racer, which shipped in special Thor box. [16] They were called board track racers because in this day, the racing courses were made of planks of wood to make the race track, hence a 'board track'. [15] The wooden tracks were called motordromes and were quite dangerous to drivers and the crowds. [15] Most of the sport's stars died racing and its popularity had diminished by the 1920s according to the Smithsonian Institution. [15]


Thor supplied engines to many manufacturers including: [5]

Thor also made parts and castings for Flying Merkel, Reading Standard, Henderson Motorcycle, and Harley-Davidson. [18]


Here is some examples of models offered: [19]

Additional examples:

Aurora also supplied Sears for a short time before they switched to a different company in the early 1910s. [25] (see also Sears Dreadnought)

1916 Model Thor

Thor 1000 cc 1916.jpg

1911 Model Thor

Thor Model CM 500 cc AIV 1911.jpg

1909 Model Thor

Thor 500 cc 1909.jpg

In museums

See also

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Thor Model U was a motorcycle that debuted in the 1910s with a 7 hp V-twin in the Thor marque of Aurora Automatic Machinery Company of Illinois. The 1913 model came with a 61 ci V-twin engine, with the V at an angle of 50 degrees. In 1914 the engine size was increased from 61ci to 76.25ci The motorcycle had chain drive with clutch and was overall a bicycle configuration with two handle bars and seat above a frame which housed the engine and connected the front and back. The V-twin has an angle of 50 degrees. By 1916, the Model U was essentially the "flagship" of the Thor lineup with a large 50 degree V-twin with mechanical valves, a magneto ignition, and a three speed transmission. These kind of features were improvements over typically features of the day like a single-cylinder engine, battery start, and two speed or even single speed;they were much closer to their bicycle origins they had just birthed from in the previous decade.

Sears Dreadnought was a motorcycle sold by Sears in the 1910s. The motorcycle featured a 70.62-cubic-inch (1,157.3 cm3) V-twin made by Spacke. It was sourced from Spacke's cyclecar and had 9 horsepower (6.7 kW). This engine was also used by Dayton, Eagle, Minneapolis and Crawford. In addition to the internal combustion engine, it also had foot-pedals like a regular bicycle.


  1. "Aurora Automatic Machinery Company (Thor Motorcycle Maker)". Retrieved 2 April 2015.
  2. 1 2 "1914 Thor". HowStuffWorks. Retrieved 2016-04-14.
  3. 1914 Thor by the Auto Editors of Consumer Guide
  4. 1 2 3 Remembering the Aurora Automatic Machine Company Jim O'Clair on Aug 24th, 2015
  5. 1 2 "Remembering the Aurora Automatic Machine Company | Hemmings Daily". Hemmings Motor News. Retrieved 2016-04-14.
  6. 1 2 3 4 5 6 7 Thor - Motorcyclepedia
  7. 1 2 3 Bonhams Lot 817 1913 Thor 61ci Model U Twin
  8. "Thor Motorcycles | Motorcyclepedia Museum". Motorcyclepedia Museum. Retrieved 2016-04-14.
  9. 1 2 Thor 1916 1000cc 7hp 2 cyl ioe
  10. 1 2 3 4 1913 Thor Motorcycle 9/28/2011 11:23:07 AM by Christian Williams
  11. Normand, Mabel; Sennett, Mack (1914-04-18), Mabel at the Wheel , retrieved 2016-04-14
  12. "1913 Thor Motorcycle". Motorcycle Classics. Retrieved 2016-04-14.
  13. "Pioneers of American Motorcycle Racing, Chapter 7". Retrieved 2016-04-14.
  14. 1 2 Pioneers of American Motorcycle Racing [small red square] by Daniel K. Statnekov
  15. 1 2 3 4 The Early, Deadly Days of Motorcycle Racing
  16. "Thor Take Honors at Amelia Island Concours d'Elegance. - Wheels Through Time". Wheels Through Time. Retrieved 2016-04-14.
  17. "1913 Sears Dreadnaught V-Twin | Hemmings Motor News". Retrieved 2016-04-14.
  18. "1916 Thor Model U » National Motorcycle Museum". Retrieved 2016-04-14.
  19. 1 2 Motorcycle Illustrated. Motorcycle Publishing Company. 1913-01-01.
  20. "Krystal Hess Rides a 1908 Thor Model 7 Motorcycle – Moto Lady". Moto Lady. Retrieved 2016-04-14.
  21. "1914 Thor Model 14A | Hemmings Motor News". Retrieved 2016-04-14.
  22. "Bonhams : 1913 Thor 61ci Model U Twin". Retrieved 2016-04-14.
  23. Motorcycle Illustrated. Motorcycle Publishing Company. 1915-01-01.
  24. "1912 Thor Model U Twin | Mecum Auctions". Mecum Auctions. Retrieved 2016-04-14.
  25., Developed by My Webshop |. "Yesterday`s The place where you buy all your antique and classic bikes". Archived from the original on 2016-04-25. Retrieved 2016-04-14.
  26. Thor motorcycle returns to Allen County Museum First Posted: 10:55 pm - June 28th, 2015