| # of Cylinders | |
| Bore (mm) | |
| Stroke (mm) | |
| Displacement (cc) |
| Common Stroke Measurements | |||
| Bike | Year | Stock bore (mm) |
stroke (mm) |
| YSR 50 | All | 40 | |
| NS 50 | All | 39 | |
| MB5 | All | 39 | |
| TZ50 | All | 40 | |
| TZR50 | All | 40 | |
| GPR50 (Derbi) | All | 39.8 | |
| RS50 (Aprilia) | All | 43.5 | |
| CR 80 | '00: 47, '01: 47.8 |
||
| KX 80/85 | 48.5 | ||
| RM 80 | |||
| YZ 80 | |||
| XR 100 | All | 53 | |
* Formula for computation developed by Jonathan Teraji of Team Calamari
