Thor Model U

Last updated

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. [1] The 1913 model came with a 61 ci (cubic inch) V-twin engine, with the V at an angle of 50 degrees. [2] In 1914 the engine size was increased from 61ci to 76.25ci [2] 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. [3] The V-twin has an angle of 50 degrees. [4] 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. [5] 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.

Thor (motorcycles)

Thor was an American manufacturer of motorcycles and motorcycle parts especially engines, founded in 1901 in Aurora, Illinois. 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.


The motorcycle was fast for its day setting some records and also competing in the Dodge City 300 according to Bonhams. [2] The Model U was preceded by the Model O, which had a different engine design. [2]

Aurora Automatic Machinery Company was based out of Aurora, Illinois, USA that produced the Thor motorcycles in the early 1900s. [6] The Model U shared parts with Model W, which had single cylinder. [7]

Related Research Articles

V-twin engine 2-cylinder piston engine in vee configuration

A V-twin engine, also called a V2 engine, is a two-cylinder internal combustion engine where the cylinders are arranged in a V configuration. Although widely associated with motorcycles, V-twin engines are also produced for the power equipment industry and are often found in riding lawnmowers, small tractors and electric generators.

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 1928.

Flat twin engine horizontally-opposed two-cylinder piston engine

A flat-twin is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. It is a flat engine with two cylinders. Used in motorcycles for more than a century, flat-twins have also been used in automobiles, light aircraft, stationary powerplants, and household appliances.


The term softail refers to motorcycles and bicycles that feature a hidden rear suspension system with springs or shock absorbers to absorb bumps. Softail motorcycles give the appearance of having a hard-tail or rigid frame, normally with the shock absorbers or springs under the motorcycle and out of view.

Henderson was a manufacturer of 4-cylinder motorcycles from 1912 until 1931. They were the largest and fastest motorcycles of their time, and appealed to sport riders and police departments. Police favored them for traffic patrol because they were faster than anything else on the roads. The company began during the golden age of motorcycling, and ended during the Great Depression.

Ducati Apollo

The 1964 Ducati Berliner 1260 Apollo was a prototype 1,257 cc (76.7 cu in) V4 engine motorcycle producing 100 bhp (75 kW) and capable of over 120 mph (190 km/h). It was never put into production, but did influence other production Ducatis that followed. Both Ducati and their United States distributor, Berliner Motor Corporation, were experiencing declining sales of existing small-capacity single-cylinder models, and sought to create a bike to compete with Harley-Davidson. Berliner Motor was keen to have a model that could win lucrative police motorcycle supply contracts, and that could also sell as a civilian touring bike.

Douglas (motorcycles) British motorcycle manufacturer

Douglas was a British motorcycle manufacturer from 1907–1957 based in Kingswood, Bristol, owned by the Douglas family, and especially known for its horizontally opposed twin cylinder engined bikes and as manufacturers of speedway machines. The company also built a range of cars between 1913 and 1922.

Excelsior Super X motorcycle

The Excelsior Super X was a motorcycle manufactured by the Excelsior Motor Manufacturing & Supply Company from 1925 to 1931. It was the most famous Excelsior motorcycle manufactured by that company and was the first American forty-five cubic inch motorcycle.

S&S Cycle

S&S Cycle is an American motorcycle engine and parts engineer and manufacturer. The company was founded in 1958 by George J. Smith and Stanley Stankos in Blue Island, Illinois. The company started by selling high performance pushrods for Harley-Davidson motorcycles, and today they still make parts for a variety of V-Twin bikes. The company's current president is Paul Langley.

The Advance Motor Manufacturing Company was a British motorcycle and engine manufacturer established in 1905. As well as supplying aircraft engines to the pioneering monoplane developers, Advance engines were also used by Captain Robert Scott to power Antarctic snow sleds. After the end of the Second World War the company was sold to Sheepbridge Engineering and became a motor supplies organisation.

Bradbury Motor Cycles

Bradbury Motor Cycles was a British motorcycle manufacturer based in Oldham, England and established in 1902. Originally involved in the manufacture of machine tools, sewing machines and cycles, their first motorcycles were bicycles with clip-on Minerva engines. The Bradbury factory went on to develop and produce a range of single-cylinder motorcycle, V-twins and horizontally opposed twins. The 1912 Bradbury motorcycles were one of the earliest with variable gearing. Although the factory survived the First World War it closed in 1924.

Indian Model O

The Indian Model O was a lightweight motorcycle made by the Hendee Manufacturing Company from 1917 to 1919. Indian expected to sell the Model O to young or thrifty riders. The United States' entry into World War I caused Indian to shift manufacture to military motorcycles, and the low cost of the Ford Model T caused the market for lightweight motorcycles to collapse.

Flying Merkel

The Flying Merkel was a motorcycle of the American company Merkel in Milwaukee, which relocated later to Middletown, Ohio. The motorcycle was produced from 1911 to 1915.


See also

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.

Harley-Davidson Model 7D

The Harley-Davidson Model 7D of 1911 was the first successful v-twin from Harley-Davidson, inaugurating a motorcycle engine configuration that has continued unbroken from the Milwaukee motor company ever since.

Harley-Davidson Model W

The Harley-Davidson Model W, also known as the Sport Twin, is a motorcycle made by Harley-Davidson from 1919 to 1923. Unusually for a Harley-Davidson motorcycle, the Model W had a flat-twin engine and a trailing link fork. The Model W set speed records on runs from New York City to Chicago and from the Canada–United States border to the Mexico–United States border. Slow home market sales led to the end of production after four years.