1915 Harley-Davidson Model 11K Twin 3 Speed Engine #6676K

• ENGINE NO: 6676K
• PAINT: Original Renault Grey
• ENGINE: 61 cu. in.
• CONDITION: Original

This 1915 Model 11K Twin 3-Speed Harley-David­son motor­cycle features a 61-cubic-inch F-head V-twin engine and a three-speed sliding gear transmission. This model is considered a landmark in Harley-Davidson’s history as it marked a serious upgrade from the previous models with twenty-nine new refinements. It was the first year to sport the three-speed gearbox and primary case clutch and gained a 37% power increase over the 1914 models due to its larger inlet valves and both valve seats being chamfered at 45° rather than the previous 60°. Among other upgrades, it also had an improved oiling system with an engine-driven oil pump.

Harley-David­son was late entering championship racing, falling behind Indian, Excel­sior, and other manu­facturers, but hired engin­eer William Ottaway from rival Thor Motor­cycles in 1913 and formed the Harley-David­son Racing Department. Bill started with a 1914 Model 10 production bike. He added new gear case covers with oil pumps cast into them to withstand the heat of racing, but at their first event in July 1914 at the 300-mile Coyote Classic in Dodge City, Kansas, only two of the six new racers made it through the race.

Ottaway would go on to produce the 1914 Model 11K Stripped Stock Racer and began touting its racing victories in advert­ise­ments, offering it in 1915 to both factory riders and select racers through its dealer network as the K Model. This Model 11K Twin is in remarkable orig­inal condition with orig­inal Renault Grey paint and pinstriping — an exceptional find for a century-old machine.

Harley-David­son, Inc. needs no introduction as an iconic Amer­ican Motor­cycle manu­facturer headquartered in Milwaukee, Wisconsin. In 1901, William S. Harley, Arthur David­son, and brother Walter David­son began work on their first Motor­cycle engine. Their first attempt may have been a failure, but they founded Harley-David­son in 1903 and became one of the largest Motor­cycle manu­facturers by 1920. They produced Motor­cycles for the United States used in both World War I & II and were one of only two major Motor­cycle manu­facturers to survive the Great Depression. In fact, they’ve survived numerous changes to ownership and restructuring, intense global competition, charges of restrictive practices, claims of stock price manipulation, and a constantly evolving view of the com­pany and bikers. Still, they are widely known for their loyal following and now manufacture in Penn­syl­vania, Wisconsin, Brazil, and Thailand. Their classic cruiser style, including high handlebars, low seats, and chrome parts, is easily recognizable. They’re also noted for their customizability, giving rise to the chopper style of Motor­cycle, and for the distinct sound of HD’s powerful engines.

From Mecum Auctions:

"In 1915, Harley-David­son offered their 61 cu-in. twin with the option of either the old single-speed chain-drive, or the new three-speed gearbox and primary-case clutch. The new gearbox had nothing in common with the previous two-speeder, which was offered for only one year for the twin. Not everyone wanted, or trusted, a gearbox on their motor­cycle, and the extra expense might not have seemed worth it if you had no large hills to climb, no great distance to travel, and no real roads over which to ride – a situation which defined quite a bit of the U.S. in 1915!

Another innovation for 1915 was an auto­matic oil pump, which supplanted 'visual' oil metering, i.e. counting drops of oil through a sight-glass in the oil line. The auto­matic pump removed a source of anxiety for the rider, and most never touched the new adjustable locknut which altered the oil flow to the motor. The oil tank was moved from the toolbox and into the left-side pannier tank which hugged the top tubes of the frame. The auxiliary hand-pump atop the gas tank, for that comforting extra dollop of oil, was retained, although the plunger now sported an 'ingenious locking device... to prevent meddlesome persons from amusing themselves by pumping the crank full of oil when the owner has left his machine standing...'

The 1915 twins had a 37 percent power increase over the 1914 models, by using larger inlet valves and both valve seats chamfered at 45 degrees (compared to 60 degrees previously). The intake manifold was larger, and to handle the significant increase in power, the crank-pin was increased to a one-inch diameter from the previous 7/8-inch, while its bearing surface was 3/8 of an inch wider than before, with all bearings now made by Harley-David­son themselves. In the motor alone, H-D claimed 29 refinements in a single year. To allow the more efficient engine to breathe more easily, a new muffler was designed, with significantly less back pressure, while 'at the same time the exhaust is but little more than a whisper.'

This 1915 twin-cylinder Harley-David­son Model 11 is in remarkably orig­inal condition, including an enamel license plate from 1925. The orig­inal Renault Grey paint is still present, as is most of the orig­inal pinstriping, which is quite a find for a century-old machine."