Thor (motorcycles)
 Thor motorcycle emblem | |
| Company type | LLC |
|---|---|
| Founded | 1901 |
| Founder | |
| Fate | Production ended in 1920 |
| Headquarters | , USA |
| Products | Motorcycles |
Thor was a U.S.-based manufacturer of motorcycles and engines, established in 1901 in Aurora, Illinois. The company initially specialized in producing engines under license for Indian Motorcycles of Springfield, Massachusetts, from 1901 until 1907, while simultaneously marketing parts and engines independently. Following the conclusion of this licensing deal, Thor began manufacturing its own complete motorcycles until approximately 1920. Among its significant accomplishments were supplying engines to various manufacturers, pioneering V-Twin engines featuring automatic valve mechanisms, and creating record-breaking motorcycles during the early 1910s.
Although motorcycle manufacturing ceased, the Thor name persisted as a brand for home appliances under its parent firm, Aurora Automatic Machinery Company, which had roots in cast metal parts production dating back to the late 19th century.
Summary
Initially providing engines to Indian between 1901 and 1907, Thor subsequently developed full motorcycle models. In 1910, it introduced a unique V-Twin engine design with one vertical cylinder. By 1913, the company advanced to larger displacement V-shaped V-Twin engines. Production of motorcycle engines stopped in 1916, with overall manufacturing activity diminishing throughout the late 1910s.
History
Thor served as the motorcycle division of Aurora Automatic Machinery Company, which first produced engines for Indian motorcycles before launching its own motorized bicycles. Aurora employed several prominent industry professionals connected to Indian, Crocker Motorcycles, and Harley-Davidson. Founded in 1886 as a machine shop specializing in bicycle components, Aurora partnered with Oscar Hedstrom in 1901 to manufacture Indian engines, delivering around 150 units by 1902. The licensing arrangement permitted Aurora to sell engines to other clients while remitting royalties to Indian.
After Indian began producing their own components, Aurora shifted focus to complete motorcycles under the Thor brand when the license expired in 1907. Thor introduced innovations such as F-head engine designs, V-Twin layouts, and mechanical automatic valves.
By 1908, Thor had incorporated automatic intake valves and provided options including battery ignition and belt drive systems. Their 1913 models featured a 1200 cc twin-cylinder engine equipped with a Schebler carburetor; updraft carburetors were standard on many models. By 1916, three-speed transmissions were available along with acetylene lamps for illumination.
Thor motorcycles gained visibility in popular media; notably, a Thor motorcycle appeared in the 1913 Charlie Chaplin film Mabel at the Wheel.
Sales declined during the early 1910s—potentially influenced by competition from the Ford Model T—leading to production tapering off by the decade’s end. Among notable models was the Model 13U, distinguished by its blue paintwork, white tires, and a twin-cylinder engine rated at seven horsepower. Preserved examples can be found in museums such as the National Motorcycle Museum located in Iowa.
Racing
Between 1909 and 1913, Thor concentrated its efforts on motorcycle racing under the leadership of William Ottaway, which played a key role in building the brand’s reputation through setting national records and showcasing advanced engine tuning skills. Competitions were mainly held on dirt tracks or wooden board tracks, known as motordromes, which, despite their inherent risks, were essential for enhancing the company’s exposure. The 1912 Thor Board Track Racer serves as a prime example of this strategy, designed with distinctive features to attract racing enthusiasts.
Engines
Thor’s operations included manufacturing engines supplied to well-known companies such as Sears (which marketed motorcycles via mail order between 1913 and 1916), Chicago, Reading Standard, Indian (Hendee Co.), and Torpedo motorcycles. Additionally, Thor provided components and castings to brands like Flying Merkel, Reading Standard, Henderson Motorcycle, and Harley-Davidson. These collaborations significantly broadened Thor’s influence within the motorcycle sector. It is noteworthy that Henderson produced motorcycles from 1912 until 1931, Flying Merkel operated from 1911 to 1915, and Sears offered Thor-powered motorcycles from 1913 through 1916.
Models
The Thor lineup featured models including the Model 13-M (4 hp single-cylinder), Model 13-W (5 hp single-cylinder), and Model 13-U (7 hp twin-cylinder), with optional two-speed gearboxes available at an extra cost. Other prominent models encompassed the Thor Model 7, Model 14A, Model O (equipped with V-twin mechanical inlet valves), Model U (a redesigned V-twin), Model V, Model M, and Model W (a 5 hp single-cylinder produced in 1911). This varied selection underscored Thor’s dedication to innovation and catering to diverse consumer preferences. For a short period in the early 1910s, Aurora supplied engines to Sears before they switched to other suppliers.
In museums
- The Allen County Museum preserves a 1912 Thor model that was honored at the Amelia Island Concours d'Elegance in 2014.
- A Thor Model 13U is part of the collection at the National Motorcycle Museum in Iowa.
- The Petersen Automotive Museum in Los Angeles exhibits a 1903 Thor Camelback.
- A 1913 Thor motorcycle is on display at the Seal Cove Auto Museum.