The Harley-Davidson RL 45 is a model of the R-series range produced from 1932 to 1936, preceded by the DL range (1929-1931), which was Harley-Davidson's first 45 cubic-inch and first flathead V-twin motorcycle, and succeeded in 1937 by the WL. The R-series range included 45-solo, R, RL and RLD models. The RL, like the DL before it, featured a total-loss oiling system; the following WL had a recirculating oil system. Prior to the Second World War, Harley's RL Sports model and Servi-Car were produced in Japan under license to the company Rikuo (Rikuo Internal Combustion Company). Production continued until 1958.

Manufacturer -Harley-Davidson
Production -1932–1936
Assembly -Milwaukee, WI USA
Predecessor - D 45
Successor -W 45
Class - standard
Engine - 45.32 cu in (742.7 cc) flathead V-twin
Bore / stroke - 2.75 in × 3.81 in (70 mm × 97 mm)
Top speed - 70 mph (110 km/h)
Power - 8.5 hp (13.8 kW)
Ignition type - 6 V, coil and points
Transmission - 3-speed
Frame type - Steel, single down tube
Suspension - Front: Leading link spring fork, Rear: None, rigid
Brakes -Front: expanding shoe, Rear: contracting band
Tires -4.00 x 18
Wheelbase -57.5 in (1,460 mm)
Weight -390 lb (180 kg) (dry)