Chain Chart
Use the image below to guide you in measuring your chain.
Chain Dimensions (in millimeters)
It's best to have a metric ruler or calipers to measure the small differences in size. The #35 and #40 are most common on large pocket bikes, mopeds, mini bikes, go karts and choppers. The #25 and #25H is most common on electric bicycles, electric scooters and the small 47cc pocket bike.
| 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 |
| T8F | 8.00 | 4.77 | 4.72 | 3.28 | 11.7 | 7.60 | .80 |
| #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 |
| #410 | 12.70 | 7.77 | 3.18 | 3.60 | 8.65 | 8.30 | 1.00 |
| #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 |