Most old-style Sturmey-Archer hub installations are around 114 mm spacing. Beware also that the axle length may matter in your installation. Sturmey AWs from the common, post-war era are usually 5-3/4 inches or 6-1/4 inches, though other variations exist. The longer size will generally work on something like a larger 120 mm frame, just add spacers to fill up the space. You begin to run out of axle if you go much beyond 120mm, considering a standard gauge dropout.