1913 Ariel 3-1/2 HP Deluxe Roadster
Engine: 498cc air-cooled side-valve T-head vertical single, 86.4mm x 85mm bore and stroke
Top speed: 60mph (est.)
Carburetion: Single Brown & Barlow
Transmission: 3-speed epicyclic hub gear, belt final drive
Electrics: Bosch magneto ignition
Frame: Steel open-cradle w/engine as stressed member
Suspension: Druid fork front, rigid rear
Brakes: Stirrup-type wheel rim brake front, leather pad on steel rim rear
Tires: 2.75 x 21in front and rear
Price then: $287 (£59, 1913)
Without question, the tensioned wire-spoke wheel was one of the most significant inventions of the 19th century.
Without it, bicycles and early motorcycles would have had to use heavy, rigid and unforgiving wooden wheels. For this innovation we have to thank James Starley and William Hillman of Coventry, England, who quickly incorporated their patented wire wheels on the bicycles Starley was manufacturing. Because their invention made their bicycles much lighter, they named them Ariel — the spirit of the air.
In 1896, Starley merged his company with Westwood manufacturing, acquiring at the same time the Selly Oak, Birmingham, England, site that would become Ariel’s home for the next 70 years. Like many cycle makers at the time, Ariel was soon experimenting with the internal combustion engine and produced its first self-powered vehicle in 1898, a tricycle with a 1.3 horsepower De Dion-Bouton single-cylinder engine driving the rear axle. By this time, Ariel had been bought by Charles Sangster’s Components Ltd. Ariel’s first two-wheeled motorcycles appeared around 1901, with proprietary engines from Minerva and Kerry.
It was an Ariel motorcycle that was selected by the Auto Cycle Union (the U.K. motorcycle sports’ governing body) to enter the 1905 International Cup Races. The 6 HP JAP-engined Ariel, ridden by J.S. Campbell, recorded the best performance with an average speed of 41mph. And while Ariel had also been experimenting with its own engines, their next significant model used an engine by Coventry manufacturer White and Poppe.
Introduced in 1909, the Ariel 3-1/2 HP used a side-valve White and Poppe single-cylinder engine with a distinctive cylinder head with diagonal fins and widely spaced intake and exhaust valves (sometimes known as a “T” head). These bikes were known as “the Ariels with valves a mile apart.” The engine was so successful that Ariel bought out the patents from White and Poppe in 1911, and started manufacturing the engines themselves, at the same time increasing the engine from 482cc to 498cc. They continued to build motorcycles with the “mile apart” valves until 1926.
1913 Ariel 3-1/2 HP
By 1913, Ariel’s 3-1/2 HP range included a TT model and the Deluxe Roadster. The TT model was intended for the Isle of Man Tourist Trophy time trials and as such was fitted with minimal equipment. The same T-head, side-valve engine was housed in a sturdy open cradle frame with dual top tubes and a Druid front fork. Fuel was by an Amac carburetor with ignition by Bosch magneto. (And yes, it’s Amac, not Amal, which was formed in the late 1920s by the amalgamation of three British carburetor makers: Amac, Brown & Barlow, and Binks.) A drip-feed total-loss lubrication system used a sight glass on the shared oil/gas tank, with a pressure plunger feed for extra lubrication if required. Single-speed drive to the rear wheel was by leather belt.
The TT model featured narrow fenders, footpegs instead of floorboards, a sprung seat, dropped handlebars, a rear carrier doubling as a pillion pad and a small leather tool pouch behind the seat tube. It retailed for £47 ($229), and was reasonably successful, placing 9th and 12th in the 1913 Senior TT.
More expensive at nearly £59 ($287) was the Deluxe Roadster model. It used the same basic engine as the TT but with a Brown & Barlow carburetor. Drive to the rear wheel was through a toothed leather belt to an Armstrong 3-speed epicyclic gear and clutch in the rear hub. A foot clutch on the right was mated to a hand shifter on the left side of the gas tank and the engine was started by a kickstart lever. In addition to the 3-speed hub, overall gearing could be raised or lowered by adjusting the engine pulley. This option was first shown at the Stanley Cycle Show in London, England, in 1910: Said the show guide, “The Ariel adjustable pulley model will also be on view, with and without pedalling gear.”
Also seen at the 1910 show was Ariel’s ingenious starting assist. Flipping a lever on the outside of the crankcase changed the intake valve lift to a “half position,” making it easier to turn the engine over. When the engine started and ran, the intake would automatically flip back to its full lift position for full power. On models without a clutch or kickstarter, the manufacturer guaranteed that with the device, “the machine will start at a walking pace within three yards.”
In addition, the Deluxe was fitted with touring handlebars and sturdier fenders, with a side valance at the rear to keep the rider’s clothing (likely a voluminous great coat) out of the back wheel. The seat also featured a sophisticated parallelogram spring system for rider comfort. Braking at the rear wheel was by a friction block acting on a dummy rim and operated by a left side foot pedal and crossover. The front brake was a bicycle-style stirrup brake acting on the wheel rim. Optional equipment would have included a speedometer and acetylene lighting set.
Jim Green’s Ariel 3-1/2 HP
The story of Jim Green’s Ariel goes back 30 years to 1987. At the time, Green was working for B.C. Hydro in the mountains of southern British Columbia about 150 miles east of Vancouver. It was near the valley town of Merritt that he found some pieces of a very old motorcycle lying on the ground near a dilapidated cabin. The bike was in a similar state.
“What I found was the frame with the engine and gas tank,” Green says. “The name Ariel was familiar. I knew it was English.” All Green knew about Ariel was that “they made a Square Four.” Green managed to locate the landowner and got permission to salvage the bike. “My work crew thought I had gone nuts,” Green says.
Returning to the site with the landowner, Green quickly located the front fork, rear sub-frame and wheels, “complete with the Dunlop tires rotting off the beaded-edge rim,” Green says. “There was also a license plate from 1922 and the rear fender. With a little more searching, we located the Armstrong shifter for the 3-speed hub gear, a spring seat pillar and footrests.” The parts were spread over an area the size of about four football fields!
Green returned to the site a number of times over the next year, and located most of the rest of the Ariel, digging into what turned out to be a collapsed building that had been totally overgrown years ago.
“It was the remains of the implement shed,” he says. “I found the speedometer and small pieces necessary for proper assembly.” Green dug down around six feet and sifted through an area of 15 by 25 feet.
Green found the seat 60 yards away, and in the remains of a bonfire a farther 100 feet away he found the twisted and flattened front fender. Also in the pile was a B.C. license plate from 1913, which Green managed to salvage, though it was badly burnt.
“I can only surmise the homesteader was planning to use the motor on a piece of machinery or some implement for the farm. There was broken down and dismantled machinery everywhere,” Green says.
Green collected all the items he could find and returned with them to his shop in Vernon, B.C. It was then, while rifling through his accumulation of old motorcycle information that he found some pictures of a 1913 Ariel 3-1/2 HP Deluxe Roadster with the same components and paint trim. That’s when he knew what he had found.
“During the months to follow, my wife knew where to find me,” Green says: “At my desk writing letters to transportation museums, Ariel owners clubs in England and the U.S., other marque clubs — anyone who may have information that would be of assistance. I was told I had a very rare and desirable machine and that there may only be one other in existence.”
Along the way he acquired a copy of a 1913 owner’s manual, sales literature, and copies of road tests by The Motor Cycle magazine in June 1912 and October 1913.
Green decided not to restore the Ariel but just to reassemble it, making repairs and replacing parts as required. It took him the best part of a year to reassemble the Ariel, keeping most of the “patina” that the bike had collected.
“It took 10 months of evenings and weekends to complete the old Ariel and put her back on the road again. What a thrill it was when the engine fired right away and ran flawlessly after being discarded for junk in 1922 — 66 years earlier! The first time I displayed her at a local vintage motorcycle show, my picture was in the newspaper,” Green recalls. “I got a phone call that night from a fellow who used to own a similar machine. This elderly gentleman came to my home with two photographs: the first was of his father astride his new 1913 Ariel taken in Toronto in 1913; the second was taken in 1920, showing a 3-year-old boy beside his father’s motorcycle in Calgary.
“He was given this machine in 1931 and operated it until 1937, when he sold it and bought a Rudge. His memory of that old Ariel was clear and intimate; after all, it was his first motorcycle. He said mine is exactly as his was. He even had spare parts still, after all these years, which he gave me. He was 73 years of age.”
Since reassembly, Green has shown the Ariel at a number of vintage motorcycle and car shows in southern BC and Canada’s western provinces. “At all these meets and rallies she has received top awards,” Green says. “She is original, complete and authentic. Only the repairs necessary were made during reassembly. The original finish remains on the fuel tank. It gives her character.”
As well as displaying the Ariel, Green also sometimes takes it out on the road — but not in rush hour, he says. “I have her geared for a top speed of 50mph. But changing the adjustable engine pulley and gearing her up, she may top 60.”
As with most early motorcycles, the bigger issue is stopping. “The problem is with the brakes — or the lack of them,” Green says. “The rear brake is a leather shoe against a ring attached to the spokes of the wheel. The front stirrup brake has pads that pull up against the rim like a turn-of-the-century bicycle. Traffic congestion wasn’t a concern before WWI.”
Of course, there was no title with the Ariel, and — like many other motorcycle restorers — Green found the most frustrating part of the recovery process was dealing with British Columbia’s provincial bureaucracy in order to get the Ariel registered for the street. Even so, he finds the finished motorcycle very rewarding. “She has been a worthwhile project, and a lot of fun since going back on the road in 1988,” Green concludes. MC
If 3-1/2 horsepower doesn’t sound like much for a motorcycle good for at least 50-60mph, you’d be right! Before 1910, when the White and Poppe engine was designed, there was no fixed method of assigning a horsepower rating to a motorcycle. So the British government invited the Royal Automobile Club (RAC) to create a horsepower formula. The formula the RAC came up with “was not intended to be a scientific statement of horse-power ... manufacturers were asked to adopt the rating for the purposes of catalogue description.” The government adopted the RAC rating system for taxation purposes.
The RAC made a number of assumptions and generalizations in coming up with their formula. For example, it ignored stroke length, basing the calculation on bore only. Their final equation: horsepower equals bore (in inches) squared, multiplied by the number of cylinders and divided by 2.5. For the 1913 Ariel 500, the formula gave a figure of 4.62 horsepower for tax purposes.
The RAC rating system has been criticized for hindering motorcycle engine development in the U.K., because the taxation formula favored smaller bore engines, so many U.K. bike makers adopted smaller bores and longer strokes. But smaller bores meant smaller valves and lower revs (for the same piston speed), limiting “actual” horsepower potential. It perhaps explains why even as late as the 1970s, British motorcycle engines were typically “under-square,” even though the RAC tax formula was abandoned in 1947.