For bike lovers who fancy vintage models, we cannot mention motorcycles without including the Harley Davidson collection, widely used for military operations, especially during World War II. In the series of Harley Davidson production, the 1939 Harley Davidson Model U is a unique model worthy of praise and remembrance for its features and functionality. This model was announced before its production in August 1929 to replace the then much-adored two-cam J type series. Before it came into the market, the Model V received many raves from all corners, and it became an instant success in the market. The manufacturer wanted to fit the 1939 model U with missing features in the 1930 model V.
Evolution of the 1939 Harley Davidson Model U
Harley produced Model V to replace F head models JD, and These models had complaints from customers because of the serious problems they presented to them in their heavy design. These issues were sorted out when model V was released, and it gained instant success as a sidecar puller and a solo mount. The V model was produced from 1930 to 1936 in 1217 and 1293 cc in two different capacities. These models were unique, and they were made available for customers with many specification details. However, the model V did not receive instant success when it came into the market because it lacked top-end power, not pleasing Harvey Davidson enthusiasts. This made the first models recalled for their engine to be redesigned.
In continuation with improvement and redesigning, Harley gave the model V big twin range a facelift. The redesigning process saw the designer use a larger crankcase that could accommodate heavy flywheels and solve the problems that the bike was experiencing. Remembering the 1939 Harley Davidson Model U was revised with a frame, wheels, and tank of the 61cu. They also added dry-sump lubrication to it and turned the model V into model U in 1937. The existing crankpin of the bike was enlarged and connected to the rods to strengthen it. The other modification done saw an improvement in the size of the flywheels. The manufacturer was considering rationalization in their production. Therefore, they changed the bore size of the OHV 61 model and the stroke used in the 80, which was improved throughout the late 1930s. The designer did no new modifications to the engine.
Harley Davidson designed around 200 Model U bikes, special bikes which Dot Robinson ordered. According to the 1939 Harley Davidson Model U factory brochures, the description of the model U indicates that this model is a side-valve motorcycle. Many riders chose these models compared to other bikes found on most Americans’ bikes on the road today. Most 1939 Harley Davidson Model U enthusiasts love the motorbikes for their solo, package truck, commercial, sidecar, pleasure, and police use. The 1939 model is powerful with a quiet motor that can deliver more horsepower to the user and give you greater satisfaction. From expert reviews on this bike, you will also enjoy greater satisfaction as the bike will give you long service without taking it for service because of the advancement of the materials and parts used, such as steel-strutted pistons, equalized cylinder lubrication, perfect valve spring covers, oil-control piston rings, and improved manifold.
Engine and Transmission
Harley Davidson Model U engine has a displacement of around 1209.0 CCM, equivalent to 73.77 cubic inches. The engine type specification is V2, four strokes with the fuel system of Linkert or carburetor. Fuel control uses side valves with a dry-sump lubrication system and chain-type transmission.
Chassis, Brakes, Wheels, and Suspension
Harley Davidson uses leading link coil springs when designing the front suspension of the U model. The rear suspension they used was rigid. The bike seat was inserted with spring-mounted parts for comfort during long rides. Front and rear brakes were the insertions for expanding the brake or drum brake. According to antique Motorcycles, other modifications used included an extended intake manifold to enlarge the area between the cylinder heads and carburetor.
How to Ride the 1939 Harley Davidson Model U
Whenever people hit the road with over 80-year-old bikes, heads will turn, and people will ask you many questions about the bike. Chances of seeing the 1939 Harley Davidson Model U are slim these days on the road and in museums. Therefore, people will want to know how to ride these antique motorcycles. Here are a few tips on the ins and outs of how to ride these old Harley models. According to Panhead Jim, the engines of this bike were designed using a 74ci side-valve engine that is V-twin, which unlike the engine used in most modern bikes; the parts of the valves are fitted inside the cylinders instead of the heads. You will find the engine mated on the hand shift, which has a three or 4-speed transmission, which you will operate using a foot multi-plate clutch.
The engine design has some similarities with the tractor engine; it can attain a speed of more than 100 mph. The oil will move from the oil tank to the crankcase. It will then travel to the primary before ending up in the rear chain. Eventually, it will go to the ground. But new oil will keep on circulating through the engine parts. It can take about 15 quarts to cover 3.650 miles. The procedure you will use to crack up an old 1939 Harley Davidson Model U is more involving than the one you will use on a modern motorbike. But when the engine warms up, it will give you a more satisfying ride. When starting a bike, first turn on the gas. Most bikes have about three built tanks and two fuel petcocks. The tank available on the right side is the main fuel tank which has its petcock that you will use to turn the fuel on and off. The other tanks on the left side are split into two to hold gas in the rear and hold oil in the front part. These tanks are controlled using the second petcock.
After opening the petcock, the fuel will run down to the carburetor. When the engine has reached prime, you can fire it up the same way you do to a modern bike. You will apply a quarter twists on the left grip, retard the timing and rotate the timer. A properly tuned machine can take one or two kicks to fire up the bike engine fully. As soon as the bike is warmed up, observe the hand shifter. You will then control the clutch with your foot pedal. When you heel down, you will disengage the clutch, and when you toe it forward, it will engage. Therefore, hells down first before shifting it forward and engaging the first gear. The final step will involve rocking the clutch pedal forward as you twist the right grip to make the engine rev. When you do it correctly, the superbike will take off smoothly. You can proceed to rock it to around 20 mph before you rock it back using the clutch pedal to change the gear. Overall, the 1939 Harley Davidson Model U comes in pleasant color combinations and styles. You can get a certificate of title and can be restored nicely according to your desire.
Written by Benjamin Smith
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