1915 Harley Special
Inside A Sons Of Speed Boardtrack-Style Racer
Text by Billy Lane
Photos by Jim Arbogast
What do you envision when someone describes a motorcycle as a boardtrack racer? The term has been applied to so many styles of motorcycles over the years, we’d like to define the term for you and share this replica racer AIM Editor in Chief Buzz Kanter will be competing on in March for Team American Iron.
There is no denying that motorcycle racing rapidly advanced the development of the motorcycle engine. Roads in the first decade of the 20th century were not conducive to high speeds. Worse, the surfaces were so rough they often destroyed the motorcycles that rode over the dirt, mud, and gravel surfaces. But that seldom mattered when two sporting riders found themselves side by side on the same road.
Visionaries like Jack Prince saw the potential of a smooth surface for high-speed motorcycle racing. So they modeled their banked board racetracks after the wildly popular bicycle velodromes. The first recognized motorcycle board track, built in 1910, was the Los Angeles Motordrome. And, as you might expect, it didn’t take long for motorcycles, designed for speeds of 25 mph on the road, to exceed 100 mph on the boards.
This new sport was so popular, motorcycle boardtrack racing quickly influenced the young manufacturers and privateers to increase speed through greater engine horsepower, creating some of the most ingenious and beautiful engine designs by way of their makers’ desire for glory on the racetrack.
But progress did not happen without problems. Rough, unpaved roads broke the brazed and soldered frames, forks, fuel tanks, and wheels of early motorcycles. Owners would remove and repurpose the engines, trashing the remainder of the motorcycle in favor of lighter and sometimes stronger designs for the track. Boardtrackers were some of the first motorcycle racers in organized events.
Stripped of all unnecessary weight or parts, they were raw performance. Big muscular engines clamped low in skinny keystone frames with braced forks and drop bar handlebars; slim wheels and skinny tires with no brakes to get in the way or slow you down; magneto ignitions, a skinny seat, and no fenders. Direct drive removed any need for transmission or clutch. The only controls on true boardtrack racers were the twist grip throttle (either cable or rod actuated), a magneto kill button, and a hand pump to override the oiling system. These were purpose-built, fire-breathing, all-out race machines!
A century later, we have a few surviving engines patiently waiting for their revival. The last boardtracks were closed in the early 1930s when motorcycle racing was relegated to flat dirt tracks. Dirt track racing required more horsepower at speeds well below those achievable on the boards.
I created Sons of Speed (SOS) to put the engines that survived two world wars and The Great Depression back on the banked track. Sons of Speed maintains as much of the raw purity of motorcycle boardtrack racing as possible, the way it was done a century ago, while promoting the sharing of information, education, diversity of brand, and safety that was absent during the sport’s peak in 1915.
At the core of Sons of Speed are vintage 1000cc twin-cylinder, air-cooled motorcycle engines from manufacturers like Excelsior, Harley-Davidson, Indian, Merkel, P.E.M., Reading-Standard, and Thor. I, along with several carefully chosen others, have rebuilt these engines to withstand the rigors of high-speed racing. Most of the troubles associated with early engines were due to carburetion and ignition irregularities, which we have overcome by improving carburetor design and modifying or replacing the magneto ignitions.
To carry these original engines around the track, I designed and built a modern version of early motorcycle half-mile racing chassis. My Sons of Speed frames employee a universal keystone design, in which most early V-twin motorcycle engines fit. The various manufacturers’ engines are bolted in the identical keystone frames via engine cradle plates. By simply replacing the aluminum engine cradle plates, an Indian or Excelsior Sons of Speed race engine can quickly be swapped into a Harley-Davidson- or Reading-Standard-powered Sons of Speed chassis. Each chassis shares the same countershaft and rear drive sprockets, forks, handlebars, wheels, seats, and tires. The only significant variation in the chassis is the shape of the fuel/oil tanks, which I created to mimic the original style of the original Flying Merkel, Harley-Davidson, or Thor designs.
Our use of lightweight aluminum parts wherever possible helps translate the limited horsepower of the early engines up to track speed. I constructed my Sons of Speed frames and forks from 1020 mild steel, seamless tubing that is drawn over a mandrel. All joints are coped and hand-fit before TIG welded in the jig to ensure joint strength. Aluminum wheel hubs feature modern sealed wheel bearings, supporting rims with 28″ clincher racing tires made from Firestone’s original molds. The result is simple, reliable, and relatively affordable race bikes, complete with interchangeable components, and all in a package that weighs less than 170 pounds.
To build a half-mile banked wooden track would cost over a million dollars—well beyond the Sons of Speed budget. But we do have a lease with New Smyrna Beach Speedway for March 17 and 18, 2017, during the 76th Daytona Beach Bike Week. The Speedway is a half-mile asphalt track with 20-degree banking, well suited for Sons of Speed racers. The Speedway’s surface may not be made of wood, but it offers so much more in the way of speed and excitement than a dirt track. We could have more than 20 Sons of Speed racers ready to go in March, so the action will be fast and furious.
In addition to racing, I am currently working on organizing a vintage custom car and motorcycle show at the track, with vendor spaces and camping. For advance tickets (tickets are limited), videos, and information, please go to our Facebook page (Choppers Inc) and follow us on Instagram @Choppers.Inc.
Shown here is Buzz Kanter’s 1915 Harley-Davidson-powered Sons of Speed racer. RetroCycle, in Boonton, New Jersey, rebuilt Buzz’s 102-year-old engine and shipped the engine to me after some test runs. I bent the top tube of Buzz’s frame to mimic the lines of an original 1915 Harley-Davidson, and then I bent and welded a set of 0.045″ aluminum fuel and oil tanks.
Prior to building Buzz’s racer, I’d built and been running another 1915 Harley-powered SOS racer belonging to Shelly Rossmeyer-Pepe. Shelly’s and Buzz’s racers are virtually identical, except for the tanks and a few small details. Both bikes share identical sprocket ratios from front-to-rear, seating, footpeg, and handlebar locations.
The original boardtrack racers ran with the pedal cranks fixed in place and used as foot rests for the rider. Since pedal cranks are of no use to us, I eliminated them from the SOS racers. The footpegs are in an exaggerated configuration, like a pedal crank, with the left peg forward of center and the right peg aft, near the rear axle. Because the riders sit so far rearward on these bikes, the unusual foot positioning makes it easier to lean our body weight inward and forward over the front wheel, which is necessary to maintain both control and speed in the turns.
My race bikes are direct-drive machines, with no clutch and no gearbox. So starting them takes some thought. We can start them with a tug on the rear wheel on a stand, or by dropping in from the top of the banked track. These engines fire to life immediately, sending us into turn number one at an alarming pace. Braking is achieved by a combination of throttling down or ignition kill and steering the bike to fight gravity on the track’s banked surface.
Throttling up on another bike from behind through a turn at 70 mph—with no brakes—will make your heart beat harder than the thumping engine a few inches beneath your chest. Because these racers are geared tall for high speeds, they decelerate fairly quickly with engine braking. But from top speed, it might take up to a half-mile to come to a complete stop. AIM
Find this story and more great articles in Issue #347 of American Iron Magazine.