These off-set sprockets are easy solution when you want to install a slightly wider tire without offsetting the primary or transmission. Fits 1980 to present 5 speed Big Tw These off-set transmission sprockets are available in 0.5 (12.7mm) off-set and .810 (21mm) off-set and in 21, 22, 23 or 24 tooth. The .810 off-set sprocket allows fitting of an O-ring chain as much outward as possible with the outer primary cover still in the original position. These sprockets must be used in conjunction with ZPN720156 spacer and ZPN022054 on pre-1994 5 speed Big Twin models.