Just three years after the launch of the first motorcycle model, BMW revised its model range for the first time. BMW R 42 was the designation for the successor to the successful BMW R 32. The BMW R 42 similarly possessed a side-valve 500 cc Boxer engine but the power output was increased to 12 hp. The frame remained virtually unchanged although the new drive shaft brake replaced the previous wedge-shaped shoe brake. Thanks to a price reduction of 30 percent, the unit volumes of the BMW R 42 more than doubled compared with the BMW R 32 to more than 6,500 units sold.