Between the World Wars

At the close of the first World War, the hardships of a war economy had drastically reduced the number of motorcycle manufacturers in the US and Europe. Americans turned to Henry Ford’s Model T for inexpensive transportation and while motorcycles had improved dramatically, demand for motorcycles declined. Those manufacturers that had prospered and invested pre-war were rewarded with a greater market share with Indian and Harley Davidson leading the way. William Harley and Arthur Davidson first incorporated in 1909 after designing and building bikes in Milwaukee, Wisconsin. Their single cylinder bikes quickly established a reputation for economy and reliability and reached an amazing record of 187 miles per gallon in a Federation of American Motorcyclist 3-day contest at decade’s end. Harley also prospered from selling over half of their production to the US Military for the war effort. The first American soldier to enter Germany after the Armistice did so on a Harley Davidson. The military also trained hundreds of soldiers as Harley motorcycle mechanics which was to benefit Harley Davidson Dealers post war. Sidecars became increasingly popular and to accommodate the increased weight, 3 speed transmissions and V twin engines filled the needs for more power. Harley Davidson’s F-Head V twin engine carried on from 1909 up until 1929 with 45 cubic inches of displacement.

New frame and suspension technologies continued industry development with Harley. The thin tubed bicycle type frames of the early century gave way to more robust steel tubing and purpose-built castings. Much had been learned from the board track and oval track racers as more powerful engines with overhead valves found their way into street machines. Coil springs were added to front suspensions aiding handling and comfort; but the rear frame remained un-sprung save a few small springs below a tractor style seat.

The Indian motorcycle built by Hendee Company in Massachusetts had become the world’s largest motorcycle manufacturer of the time. Speed and performance became Indian trademarks reaching speeds of 114 mph in 1918. Early innovations by Indian included electric lights and starters along with swinging arm leaf spring rear suspensions. There were parallels in available engine sizes between Indian and Harley Davidson as the two companies tried to outmaneuver each other. The rivalries carried over to the racetrack as well. By the 1930’s Indian performance motorcycles such as the Scout were victorious in the inaugural Daytona 200 race while Harley Davidson garnered racing accolades in the 1931 Jackpine Enduro offroad race with their 45 cubic inch flathead machine as well as numerous land speed records for the engine size. The larger Indian Chief and Big Chief bikes, 61 and 74 cubic inch engines respectively, grew wide valanced fenders that mirrored the art deco styles found in the 1930’s streamlined autos.

Hard hit by the Great Depression, other American builders like Henderson and Excelsior were soon out of business leaving the sole survivors as Harley and Indian to endure into WW2.

Across the Atlantic, Britain’s BSA, Rudge, Ariel, Triumph, and Vincent motorcycles fueled a growing market looking for cheap transportation in what was considered by many as the Golden Age of British motorcycling. Tourist Trophy road racing at locations such as the Isle of Man had widespread following as each brand fought for supremacy on the track and on the street. Among those was Cotton Motorcycles of Gloucester with their 500cc single cylinder machine. Wealthy sportsmen and social elites took the road on Brough Superior V twin powered bikes, billed as the “Rolls Royce of Motorcycling”. Edward Turner’s Triumph Speed Twin parallel 500 engine was considered an engineering marvel and graced their motorcycles until the 1970’s. On the continent, German BMW and Italian Moto Guzzi borrowed heavily from aircraft technology to develop their engine components. Moto Guzzi’s single 500cc engine featured an overhead gear driven cam shaft while BMW’s flat “boxer” twin achieved Land Speed record of 174mph in the late 1930’s.

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+ 1923 Merkel Motor Wheel

By 1915, the motorcycle had solidified itself in American society, and companies like Indian were selling 30,000 motorcycles or more per year. Interest in motorcycles was so high during this time, the bicycle motor attachment was reintroduced to the market after receiving very little attention for a decade. While Merkel had already established themselves in the market with their high performance motorcycles, the company began production of their Merkel Motor Wheel, 20 years after Joseph Merkel first designed a motorized bicycle attachment.

World War I had essentially depleted existing U.S. motorcycle companies of their materials, as their efforts were shifted to war production. After the War ended, Merkel needed an inexpensive way to enter the market again, and the Motor Wheel was launched. One of Joseph Merkel’s main goals behind the new Merkel Motor Wheel was to produce a motor which could be easily attached to any bicycle in the shortest amount of time. The design was effective, though if the rider got a flat rear tire, the entire Merkel attachment needed to be removed to replace the tire.

The Merkel Motor Wheels offered adequate performance considering it cost under $100 when new. They pulled well from low speeds, handling rough terrain and poor roads well. Riders noted that a top speed of 35 MPH was achievable, and while the Motor Wheel had just a half-gallon fuel tank, bikes could often run for 50 miles on a full tank of fuel. While it may have been a peppy and fun way to travel, it was far from smooth; riders were required to keep their weight on the bicycle when they started the motor, or else the significant vibrations might have caused bicycle to take a trip of its own!

Just 2000 of these Merkel Motor Wheels left the factory, far less than the 5000 they had hoped to produce, and perhaps less than 10 still exist today.

Specifications:

Engine: 12 C.I. Air-Cooled Single-Cylinder
Horsepower: 2.5
Top Speed: 35 MPH

+ 1926 Moto Guzzi C2V ‘Twin Spark’

The Moto Guzzi C2V was Moto Guzzi’s first race machine, introduced in 1923. The “Corsa Due Valvole” (“racing two-valve”) was launched just two years after Moto Guzzi was founded in 1921. This rare ‘twin-spark’ version is equipped with dual spark plugs. Moto Guzzi used racing to promote their machines and the C2V was used exclusively by the factory race team. At Monza, the C2V set a new lap record of 77mph. In 1924 it was offered to the public as a production racer, continuing until 1927, by which time approximately 200 examples had been built. Designed by aircraft engineers Carlo Guzzi and Giorgo Parodi, the C2V was considered exceptionally advanced for the day. A single horizontal cylinder, integral gearbox and a heavy external flywheel on the left. This layout was used in many different variants until 1976.
Moto Guzzi is the oldest European motorcycle manufacturer, established in Mandello del Lario, Italy on 15th March 1921. Moto Guzzi celebrates 100 years of continuous production this year. Active in racing until 1957, the company secured an impressive number of victories including 14 world Grand Prix championships and 11 Isle of Man TT wins. In the years after World War II, Moto Guzzi focused on small-capacity motorcycles to meet the demand for cheap, personal transport. In 1950 Moto Guzzi became the first manufacturer worldwide to install wind tunnel, helping Moto Guzzi to retain its competitive edge in racing. The stunning V8-engined Guzzi Otto Cilindri (“Eight cylinders”) revealed in 1955 shocked the motorcycling world. This water-cooled, double overhead-camshaft machine was developed to contest the 500cc championship. Achieving 172mph in testing, it would be 20 years before that speed was reached again in Grand Prix racing.

Specifications:

498cc single-cylinder
air-cooled OHV motor
17bhp
3-speed transmission
75mpg; 75mph top speed

+ 1928 Harley Davidson JD

Harley Davidson introduced the JD in 1928 as the best and fastest production street machine of its time. It featured a larger, more powerful version of its FH motor with twin cams actuating overhead valves in each cylinder and either single or twin headlights. A front brake was another first for Harley Davidson which was needed as the JD would achieve speeds of over 100mph.

Harley Davidson’s intent to build a high-performance motorcycle was a result of a dramatic shift in demand for bikes during the 20’s. In Europe, motorcycles as transportation remained viable, but in the US, inexpensive Model T Fords and similar mass-produced autos cut motorcycle sales dramatically. This left only sporting and pleasure riders left to buy new bikes. At the same time, Indian Motorcycles made by the Hendee Company were winning most every US bike race, so it was incumbent of Harley Davidson to retain a performance edge over its largest competitor.

The JD excelled in every way. Its twin cam engine had previously only been available on racing machines. A special throttle-controlled engine oiler system helped keep the engine lubricated at higher speeds along with larger cooling fins on the cylinders and cylinder heads. The frame was more robust to handle the large 74 cubic inch engine and ride comfort was improved by a cantilevered “springer” front suspension.

Sadly, the JD lasted only two model years. The Great Depression of 1929 was to further curtail motorcycle sales and demand for recreational motorcycles became non-existent. Harley Davidson was fortunate to survive the Depression as other US makers such as Henderson, Excelsior, Ace, and Cleveland all fell prey to the economy.

Specifications:

Engine Displacement: 74 Cubic Inches (1208cc)
Horsepower: 12 hp
Top Speed: 85-100mph
Transmission: 3 Speed Side Shift/ Foot clutch

+ 1929 Brough Superior SS100

The Brough Superior SS100 (Super Sports) was designed and built by George Brough in Nottingham, England in 1924. The first bespoke motorcycle with components chosen from many different suppliers, the SS100 was designed to meet specific customer requirements. All bikes had a guarantee that they were capable of 100 mph. In 1928, George Brough broke his own world record with a 130.6 mph run.

Every owner was encouraged by Brough to suggest their own ideas for developing the SS100, which meant that almost all of his motorcycles were uniquely hand-built and the design continually evolving, no two Broughs are exactly the same. Owners had multiple options of handlebars, exhaust shape and much more. Brough utilized the best motorcycle parts and features and united them together in the SS100. For example, the castle forks at the front of the bike are essentially derived from Harley Davidson designs of the time. All of this came at a cost: in 1929, you could buy a small house for the price of a Brough Superior.

T. E. Lawrence (known as Lawrence of Arabia) bought one of the first SS100s in 1925 having previously owned three Brough SS 80s. The crash that would end Lawrence’s life came while riding another SS100, on a narrow road near his cottage near Wareham in 1935. The accident occurred because a dip in the road obstructed his view of two boys on bicycles. Swerving to avoid them, Lawrence lost control and was thrown over the handlebars. He was not wearing a helmet and suffered serious head injuries that left him in a coma; he died after six days in hospital. One of the doctors attending him was a neurosurgeon, who began a long study of what he saw as the unnecessary loss of life by motorcycle dispatch riders through head injuries. His research led to the use of crash helmets by both military and civilian motorcyclists.

Specifications:

Engine: OHV 50-degree Twin-cam KTOR JAP (made by J. A. Prestwich) V-twin
Displacement: 998 cc (60.9 cu. in.)
Horsepower: 50 bhp (37 kW)
Transmission: Sturmey-Archer 4-stud 3-speed hand-change gearbox

+ 1930 Indian 101 Scout

The Indian Motorcycle Company produced two models that were to define the company throughout its history: the Scout and the Chief. This 101 Scout is considered the most refined and desirable of all the Scout models and was the basis for most of Indian’s success in competition.

Originally introduced as a 37 cubic inch model back in 1919, the Scout was the brainchild of designer Charles Franklin, an Irish engineer who was to refine the motor over the course of 10 years. 1926 saw the Scout engine grow to 45 cubic inches, in part to be competitive in races sanctioned by the newly formed American Motorcyclist Association. While the smaller Scout engine was still offered throughout the 20’s, very few were sold.

In Mid-1928, Indian released Franklin’s masterpiece the 101 Scout. It featured an increased rake front fork with a lower seat height. With a lightweight frame and lower center of gravity, it soon became the most desired sporting and stunt bike in the country. Soon Indian was to feel the effect of the Great Depression and was helped out of near bankruptcy by the DuPont family, who sacrificed their automotive future to save the struggling motorcycle company. By 1931 Charles Franklin fell ill and passed away leaving a void in motorcycle development. 1932 was to be the final year of the 101 Scout and the lightweight frame used so successfully was replaced by a heavyweight frame designed to support the much larger Indian Chief. This was to save money by utilizing the same frame for every bike model in the Indian lineup. The DuPont’s financial strategy might have saved the company, but in doing so, the 101 Scout lost its soul.

Specifications:

Engine Displacement: 45 Cubic Inch (748cc)
Horsepower: 22 hp
Transmission: 3 Speed Hand Shift, Wet Clutch
Weight: 374lbs wet

+ 1934 Cotton JAP

Cotton was an enduring English motorcycle brand founded in 1918 and produced both 2 and 4 stroke engine machines for the road and track. The most notable innovation of Cotton was their triangulated frame designed and patented by Frank W. Cotton, the company’s founder. The frame tubes essentially formed a straight line from the steering head to the rear wheel creating a frame with little or no flex at high speeds. As did many British manufacturers, Cotton made the frames and running gear and outsourced engine production from specialists.

This 1934 utilizes an OHV single cylinder J.A.Prestwick 495 cc engine with a 3-speed hand shift gearbox. It was one of many engines available when ordering a Cotton. Other engine options included Villiers, Rudge Python, Sturmey-Archer, and Blackburne. In total, Cotton offered 19 different models in 1934. A coil spring front suspension and front and rear brakes were outfitted. Cotton made quite an impressive racing reputation in Tourist Trophy races at the Isle of Man. Throughout the 1920’s at the hands of racing hero Stanley Woods, Cotton gained accolades for racing victories at the challenging 38-mile road circuit. He would win 10 individual TT victories, all with Cotton. The 1926 Junior TT would see Cottons finishing first, second, and third in the race.

After Cotton re-emerged in the wake of WW2, they would abandon the triangulated frame design and switched to 2 cycle off road competition motorcycles, sourcing many of their engine from Villiers. While concentrating on purely dirt competition machines in limited numbers, the Gloucester based company endured all the way until 1980 when it finally shut its doors.
On loan from the Wayne Carini Collection

Specifications:

Engine displacement: 495cc
Horsepower: 8hp (estimated)
Top Speed: 85mph

+ 1937 Rudge Ulster

Advertised as “probably the fastest 500cc in normal production”, the Rudge Ulster offered a level of comfort and refinement that was unmatched among high-performance motorcycles. Distinguished from two other Rudge 500cc models, the Ulster has an aluminum-bronze four-valve cylinder head with enclosed valve gear. The Ulster was named after Rudge’s 1928 famous race win in the 1928 Ulster Grand Prix, which was won by Graham Walker, father of famed motor-racing commentator Murray Walker. The race was won at over 80mph – the first time any road-race had been won at this speed. Although originally intended as a prototype racing motorcycle, it was offered to the public and was essentially became one of the first ‘race replicas. The heart of Rudge performance was its unique cylinder head, which featured four valves operated by branched rocker arms and pushrods. This allowed higher engine speeds, while the bronze-alloy material used for the cylinder head was provided superior thermal conductivity and improved cooling at the cost of a small weight penalty.

The cycle parts were no less revolutionary: the foot brake pedal operated both the front and rear brakes, with the handlebar brake lever also operating the front brake. An adjustable spring-loaded compensating device allowed the rider to change the front-to-rear brake balance. The large hand-lever was a patented main-stand operating device.

In addition to Walker’s 1928 Ulster Grand Prix win, in the same year Ernie Nott secured a two-hour record at over 100mph, a spectacular achievement at the time. Rudge continues to be a competitive force in classic racing: at the UK’s rain-soaked 2016 Goodwood Revival Rudge-mounted Charlie Williams and Mike Farrell beat a star-studded line up (including Troy Corser and Michael Dunlop) to win the Barry Sheene Memorial Trophy.

Specifications:

499cc single-cylinder
air-cooled OHV motor
4-speed transmission
60mpg; 90mph top speed

+ 1938 Brough Superior SS80 with ‘Petrol Tube’ Sidecar

The designation Brough Superior was coined by George Brough as a response to the machines his father made pre-WW1, which were merely known as ‘Broughs.’ Frequently referred to as the ‘Rolls-Royce of motorcycles,’ Brough began to advertise itself as such when the company gained explicit permission to use the term after a Rolls-Royce executive toured the Brough factory.

Alongside his machines, Brough always offered a range of sidecars, an important market segment in the 1930s, though this SS80 and its sidecar are an incredibly special pair: this sidecar is an example of a Brough made sidecar, which is still paired with the same SS80 it left the factory with.

The SS80 model name dates from 1922, when a JAP-powered model was guaranteed to do the then phenomenal speed of 80mph, with the famous racing Brough ‘Old Bill’ amassing an impressive competition record. The SS80 re-appeared as part of what became the final range of Brough Superior machines in 1935, using the excellent AMC side valve V-twin, as fitted to the Matchless Model X, though with subtle differences in specification and a crankshaft to Brough’s preferred design. A total of 159 Brough Superiors were built in 1938, and of the 3048 total Superiors that left the Nottingham factory during the 20-year production run, 1086 were SS80 models.

The fit and finish of the sidecars offered by Brough were of the highest standard, as were the motorcycles. These sidecars all offered good protection from the elements. Many of the earlier sidecars were built to Brough Superior specification, while later sidecar frames were manufactured in the Brough Superior factory. Later sidecars were unique in the fact that the frame of the sidecar held fuel. The sidecar frame looped over the top of the sidecar body and had a filler cap at the topmost position. Fuel was pressurized by a hand pump that transferred fuel from the sidecar to the petrol tank on the motorcycle. Two different bodies could be ordered for the petrol tube sidecar: cruiser or sports.

Specifications:

Engine: 982cc Matchless V-Twin Engine
Horsepower: 45
Transmission: 3-Speed Hand-Shift Gearbox
Suspension: Castle Fork Front Suspension with Friction Damper and Rigid Rear Suspension
Brakes: Front and Rear Drum Brakes

+ 1943 Indian Sport Scout

While documented as a wartime build, this Indian Sport Scout represents the one of Indian’s most important motorcycles for on and off the track performance. Locally owned and restored, this bike replicates features of the Sport Scout based upon the model 640 Indian frame. With a 45 cubic inch engine that was similar in design to the 101 Scout of the late 20’s and a down sized frame from the larger Indian Chief, the Sport Scout made its debut in 1934 just as Indian was struggling to rebound from the financial ravages of the Great Depression. Motorcycles were not generally considered primary forms of transportation in the US and so new models had to appeal to sporting riders. The Sport Scout fit that bill and met all the criteria of the American Motorcyclist Association new Class C production racing rules adding to its popularity. And when lined up against the RLDR and later WR models from Harley Davidson, the Sport Scout compiled an impressive racing record, including a victory by Ed Kretz in the inaugural Daytona 200 and Laconia 200 in 1937.x

These bikes could be used in a myriad of ways, on or off road. It featured a sprung girder front suspension and rigid rear, with brakes on front and back wheels. A magneto distributor ignition and separate Autolite lighting generator provided the bike with reliable electrics for street riding. The frame consisted of two parts known as a keystone design where the engine becomes an integrated frame member. Shifting the 3 speed transmission was done with a hand shifter and foot clutch and the throttle was on the left handlebar grip.

500cc and 750cc (called the 640-B) versions of the Scout were used in WW2 and post war models such as the 648 “Big Base” engine allowed for stronger Chief engine components to fit into the smaller frame bike. The Sport Scout V twin was replaced by a new parallel twin in 1949 but remained competitive on the race track well into the following decade.

Lent by Bess Walker in memory of Luke Walker.

Specifications