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.