Specs compared
Triumph TF 250-X 2026 vs Yamaha YZ125 2027
Motocross, stock specs side by side. Each value names the page it came from; a blank on either side stays blank.
Printed differently: engine, stock gearing, fork travel, shock travel, seat height and weight. The same on both: front tire and rear tire. Checked 28 Sep 2026 and 16 Oct 2026.
| Spec | Triumph TF 250-X 2026 | Yamaha YZ125 2027 |
|---|---|---|
| EnginePrinted differently | 250cc 4T | 125cc 2T |
| Stock gearingPrinted differently | 13T / 48TManufacturer spec sheet (research) | 13T / 49TOwner's manual p. 2-3 |
| Final drive ratio | 3.69 : 1Calculated from the stock sprockets | 3.769 : 1Owner's manual p. 2-3 |
| Chain pitch | Not yet verified | 520Owner's manual p. 2-7 |
| Front tireSame | 80/100-21Manufacturer spec sheet (research) | 80/100-21 51MOwner's manual p. 2-5 |
| Rear tireSame | 100/90-19Manufacturer spec sheet (research) | 100/90-19 57MOwner's manual p. 2-5 |
| Fork travelPrinted differently | 310 mm (12.2 in)Manufacturer spec sheet (research) | 300 mm (11.8 in)Owner's manual p. 2-6 |
| Shock travelPrinted differently | 305 mm (12.0 in)Manufacturer spec sheet (research) | 315 mm (12.4 in)Owner's manual p. 2-6 |
| Premix ratio | Not yet verified | 30:1Owner's manual p. 2-2 |
| Coolant capacity | Not yet verified | 930 ml (31.4 fl oz)Owner's manual p. 2-2 |
| Seat heightPrinted differently | 960 mm (37.8 in)Manufacturer spec sheet (research) | 980 mm (38.6 in)Owner's manual p. 2-1 |
| WeightPrinted differently | 104 kg (229 lb)Manufacturer spec sheet (research) | 96 kg (212 lb)Owner's manual p. 2-1 |
Each value shows where it came from. The bike pages list the document, page and date checked. “Printed differently” only says the two documents print different figures; it is not a judgement of either bike.
Stock sizes at MotoSport. Triumph TF 250-X: Front tires 80/100-21 · Rear tires 100/90-19. Yamaha YZ125: 520 chains · Front tires 80/100-21 · Rear tires 100/90-19. These are affiliate links: we may earn a commission, at no cost to you, and it never changes the specs. Affiliate disclosure.