motocross / default rider 183 cm
Yamaha YZ125 vs Yamaha YZ426F ergonomics
Yamaha YZ125 and Yamaha YZ426F have modeled posture scores within three points for the 183 cm default rider. Treat this as a planning estimate; posture preference, data confidence, and a real test sit still matter.
Modeled fit comparison
Yamaha YZ125
All contacts reached
Yamaha YZ426F
All contacts reached
The modeled scores are within three points, so the result does not distinguish a higher-scoring bike. Treat the result as a planning estimate and compare each bike's geometry confidence before a real test sit.
Rider fit: reaching the ground
The Yamaha YZ125 lists a 998 mm seat; the Yamaha YZ426F lists 998 mm, within a few millimetres of each other. Seat height is only a first-pass ground-reach input. It does not establish safety or actual foot contact. Seat width, suspension sag, boots, mobility, load, and individual proportions can materially change the result.
Geometry snapshot
| Spec | Yamaha YZ125 | Yamaha YZ426F |
|---|---|---|
| Seat height | 998 mm | 998 mm |
| Wheelbase | 1,443 mm | 1,490 mm |
| Wet weight | - | - |
| Displacement | 124 cc | 426 cc |
Posture metrics
Knee angle
- Yamaha YZ125
- Sport (58.0 deg)
- Yamaha YZ426F
- Sport (58.1 deg)
Hip angle
- Yamaha YZ125
- Neutral (94.2 deg)
- Yamaha YZ426F
- Neutral (93.2 deg)
Elbow angle
- Yamaha YZ125
- Relaxed (143.3 deg)
- Yamaha YZ426F
- Relaxed (143.3 deg)
Torso lean
- Yamaha YZ125
- Neutral (11.9 deg)
- Yamaha YZ426F
- Neutral (12.6 deg)