Chain Chart

Chain Dimensions (in millimeters)

The #35, #40, and BF05T are most common on large pocket bikes and choppers. The #25H is most common on scooters and the small 47cc pocket bike. Refer to the chart and image below to identify your chain.

Chain Chart

Chain Dimensions (in millimeters)
Chain No. Pitch Roller Diameter Width Between Inner Plates Pin Diameter Pin Length Inner Plate Depth Plate Thickness
  P d1 max b1 min d2 max L max h2 max t/T max
#25 6.35 3.30 3.18 2.31 7.90 6.00 0.80
#25H 6.35 3.30 3.18 2.31 8.90 6.00 1.04
BF05T 8.00 4.71 4.61 3.05 11.48 7.60 1.3/1.04
#35 9.53 5.08 4.77 3.58 12.40 9.00 1.30
#40 12.70 7.95 7.85 3.96 16.60 12.00 1.50
#081 12.70 7.75 3.30 3.66 11.20 9.91 0.90
#219H 7.774 4.59 5.00 3.01 11.90 7.40 1.2/1.04
#270H 8.50 5.00 4.75 3.28 13.15 8.45 1.8/1.4
#415 12.70 7.77 4.76 3.60 11.00 9.70 1.00
#415H 12.70 7.77 4.76 3.96 13.10 12.00 1.50
#420 12.70 7.77 6.25 3.96 14.70 12.00 1.50
#428 12.70 8.51 7.75 4.45 16.70 11.80 1.60
#428H 12.70 8.51 7.85 4.45 18.80 11.80 2.03
#520 15.875 10.16 6.25 5.08 17.50 15.09 2.03
#525 15.875 10.16 7.95 5.08 19.30 15.09 2.03
#530 15.875 10.16 9.40 5.08 20.70 15.09 2.03