Home Automotive Royal Enfield: The Roots are Recreated

Royal Enfield: The Roots are Recreated


Gordon May, in period attire showing off Royal Enfield’s Project Origin, based on Royal Enfield’s first motorized bicycle prototype from 1901. (Royal Enfield/)

Does anything from the Industrial Age ever get “lost”? All kinds of things get lost, including paintings from centuries ago, religious scrolls and important correspondence. But it’s hard to think of anything mass-produced disappearing. There’s always blueprints, records, or technical specs. Right?

It’s been 122 years since Royal Enfield built its very first motorized bicycle prototype. Two world wars and two depressions later, eight recessions followed by a move to India, meant that this important part of motorcycling’s history was lost.

Can you make this? One of the few surviving images of Royal Enfield’s first motorized bicycle prototypes.

Can you make it? One of the few surviving images of Royal Enfield’s first motorized bicycle prototypes. (Royal Enfield/)

Any company’s first prototype or production model is an obvious symbol of pride. But it also contains a company’s spiritual DNA. What is the case? A mile away from Royal Enfield North America’s Milwaukee headquarters stands another example of corporate pride, aka the Harley-Davidson Museum.

Gordon May felt Royal Enfield’s history was no different. As an author of books about Royal Enfield’s history and a member of the Royal Enfield brand team, May was recently appointed as Royal Enfield’s in-house historian. How does one go about getting this job?

“At a press event, our CEO mentioned that Royal Enfield’s heritage was so important they had an in-house historian. I realized he was talking about me.”

In-house historian Gordon May assembles a dragnet of clues as to how the prototype was built.

Gordon May, an in-house historian, gathers clues about how the prototypes were built. (Royal Enfield/)

Royal Enfield’s upcoming 120-year anniversary sparked an idea. During a historical presentation about the upcoming 120th anniversary, May issued a challenge to the Royal Enfield engineering and design teams: Build a faithful, working replica of Royal Enfield’s first-ever motorized bicycle prototype. It was impossible to do this without blueprints or technical drawing, as the prototype had long been lost. Easy-peasy.

A corps of volunteers was formed with a few black-and white photographs, an old 1902 brochure and some illustrated articles from 1901. Enlistees of Royal Enfield UK teamed up with Indian technical center Harris Performance and various vintage motorcycling experts to recreate the oldest motorcycle made by the oldest motorcycle maker still in business.

CAD drawings were crucial in turning guesswork and conjecture into technical information and blueprints.

The use of CAD drawings was crucial to converting conjecture and guesswork into technical information and blueprints. (Royal Enfield/)

May summarizes the mission. “For us as a brand, to be able to show our origins and share them with the community around the world is really important.”

The Stanley Cycle Show was held in London, in 1901. This is where the lost prototype made its debut. “Prototype” is a bit misleading. It was for sale, at 50 pounds sterling, or about 4,000 pounds or $5,200 in today’s money. The product was produced, but there are no records of how many units were made. May estimates 200 could have been manufactured.

It featured a 239cc single-cylinder engine that put out roughly 1.75 hp, designed by Frenchman Jules Gobiet who worked closely with Royal Enfield’s co-founder and chief designer, Bob Walker Smith. The French were early leaders in engine design, with De Dion, Peugeot, Société Buchet, and Griffon mills found in many fledgling automobile and motorcycle designs. None other than Harley’s first V-twin, the Model 5-D, was inspired by a Griffon engine.

Whatever you do, don’t forget the oil. A detail of the 239cc single-cylinder engine with brass hand-operated oil pump on the right.

Whatever you do, don’t forget the oil. Detail of the 239cc one-cylinder engine, with the brass hand-operated pump on the left. (Royal Enfield/)

The Royal Enfield Project Origin frame begins to take shape.

The Royal Enfield Project Origin frames begins to take form. (Royal Enfield/)

It was time to bring history to life. Engineers armed with fragments of information began to make educated guesses regarding 120-year-old technologies.

“Our engineers understand disc brakes. They don’t understand drum brakes, let alone band brakes. They know overhead valves, not atmospheric inlets.”

Harris Performance was involved in the creation of the chassis. Some of the prototype is made up of period parts such as wheel rims or hubs. Other parts include handlebars and band brakes. The majority of the time, parts are made using CAD and only old photographs as guides. There was one positive thing about them. A rich history of bicycles meant that frame construction was a well-known process.

Every book ever written about Royal Enfields (including May’s own) assumed the engine was a Belgian Minerva engine, but it turned out to be a copy of a Ducommun of Alsace engine. They used CNC machining to create the crankcase from a single billet aluminium block, while using a De Dion donor cylinder head. The cylinder sleeve was cast iron.

Fabricator Ian Bain built the Project Origin tank (with three compartments) out of a single piece of brass.

Ian Bain fabricated the Project Origin tank with three compartments out of a single brass piece. (Royal Enfield/)

A single, simple line drawing in a 1901 brochure was the only help in building the brass tank, here recreated in CAD.

The only guide to building this brass tank was a simple line drawing from a brochure published in 1901. It has been recreated here in CAD. (Royal Enfield/)

Project Origin may seem to unfairly benefit from recent advancements in metallurgy. But despite the garden shed origins of many early motorcycle “manufacturers,” engine makers were often a separate enterprise. Despite CNC machining, they had access good materials. May explains that the majority of early engines were built from virgin steel and not recycled metals.

Unit construction was a distant innovation on the horizon and with its horizontally split cases, the first Royal Enfield prototype wasn’t typical. This design was designed to prevent oil from leaking out onto the front wheels, which is a safety measure. May asked me how they had hidden this amazing invention from Triumph, the rival brand for over 70-years. May is amused, but she doesn’t laugh.

“Actually, the Royal Enfield Bullet from 1931 also featured vertically split cases, so Triumph certainly wasn’t alone.”

Vertically split cases do offer more flexibility in terms of design for the transmission. Horizontally divided cases, while less prone for leakage, require designers to place the transmission and crankshaft on the same plane.

A detail of the carburetor attached to the fuel portion of the brass tank. Note the bleed pipe (right side) coming from exhaust, to help warm the fuel-air mixture.

Detail of the carburetor on the fuel tank. The bleed pipe on the right side is coming from the exhaust and will help warm up the fuel-air mix. (Royal Enfield/)

In 1901, there were few design standards or best practices. Royal Enfield made bicycles, assorted parts and accessories since 1882. The first motorized bikes were simply existing bicycle frames that had an engine attached. What was the “best” way to do this? Answers were only found through trial-and-error. Driving the rear wheel from a forward-mounted engine above the front wheel was an improvement over a front-driven wheel, which resulted in “side slip.” The original rawhide drive belt has been replaced with a modern rubber one.

Who gets to ride Project Origin then? May is the only man who gets to ride Project Origin. He says it requires a lot of operational awareness.

“That was a journey of discovery as well,” May dryly notes.

The throttle is controlled by pulling the handlebar lever, which activates valve lifters. The motor runs at maximum throttle even though the carburetor is adjustable via a lever. Squeezing on the valve-lifter will open the exhaust vents and eliminate the vacuum which draws fuel and oxygen into the combustion chamber. Basically, you just “de-power” the engine to slow your roll.

The left side of the hand-built brass tank containing the trembler coil, oil tank, and fuel tank.

The left side of a hand-built brass tank that contains the trembler, oil tank and fuel tank. (Royal Enfield/)

A period-correct motorized bicycle deserves a period-correct murky workshop. Project Origin patiently awaiting its closeup.

A period-correct motorized bike deserves a murky workshop. Project Origin is patiently waiting for its closeup. (Royal Enfield/)

The tank is the most impressive part. The tank is made of one single piece of solid brass. There are three separate compartments for the oil, fuel, battery and tremblor, instead of a magneto. This is the only way they know because they found a 1902 ad with a simple, line-drawn tank.

For period-correct work you’ll need period tools. To build the tank, they used Victorian soldering tins from that era. The coil wiring was run through brass tubes in the oil and fuel tanks to the cylinder head. Each compartment is divided by baffles. It’s certainly a neat, tidy, and safe-ish design solution.

A small amount of fuel is added to the cylinder to help with starting. Horn is on the right, carb manifold is on the left.

To help the engine start, a small amount of fuel can be added to the cylinder. The carb manifold and horn are on the left. (Royal Enfield/)

What are some other notable engineering achievements? The trembler coil offers excellent combustion because it generates a steady stream of spark. The carburetor is connected to a bleedpipe from the exhaust system to help warm the mixture of air and fuel. That’s assuming it starts at all. The carburetor is located beneath the engine with an upward manifold of 18 inches. It can be difficult to start on cold English and Milwaukee days.

“We’ve put towels in boiling water and wrapped them around the inlet to help start it.”

Now to address the question on everyone’s mind: Does it rip? May says it corners well and develops speed quickly.

“I’ve gone pretty fast around bends. It’s good, I feel confident in how it handles.”

So what’s the top speed?

“We had a car ahead filming my ride, and we easily hit 35 mph. I was urging him, ‘Faster, faster!’ since I didn’t know if I was going to make it up the next hill.”

Gordon May powering through a bucolic English town. He’s the only authorized rider for Project Origin.

Gordon May in a bucolic English village. He’s the only authorized rider for Project Origin. (Royal Enfield/)

Gordon May handling public relations duties and fielding questions via Zoom from Royal Enfield North America’s Milwaukee headquarters.

Gordon May handling public relations duties and fielding questions via Zoom from Royal Enfield North America’s Milwaukee headquarters. (Royal Enfield/)

Oil must be injected every 10–15 minutes, as lubrication is total loss. May explains it uses Castrol, so it has “that wonderful smell.” The glass used in the oil pump had to be hand-blown, nicely matching the hand-operated pump.

“The first half-mile, you’ve got billowing smoke. Then it starts to run really cleanly and it’s beautiful. Then, you begin to experience anxiety. There’s a tendency to over-oil things.”

The cost, risk, and complexities of early motorized bicycles clearly wasn’t much of a deterrent. They were addicted then as they are now. Even 120 years on, the thrill of minimalism and mastery over risk is still apparent. Royal Enfield’s Project Origin brings history to life in the best way possible. It’s smoke, clatter, and wide grins. Royal Enfield’s classic slogan says it all. “Pure motorcycling” indeed.

More than a village, it takes an international team of builders, engineers, and experts to recreate a 120-year-old motorcycle.

It takes more than a village to recreate a motorcycle that is 120 years old. (Royal Enfield/)

Continue reading…

Previous articleAfter Supreme Court ruling, UNC bans consideration of race in hiring and application essays
Next articleWake up! MBTA suspends employee for sleeping at work