motocross / default rider 183 cm
Beta Motor RX 300 vs Yamaha YZ125 ergonomics
Beta Motor RX 300 and Yamaha YZ125 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
Beta Motor RX 300
All contacts reached
Yamaha YZ125
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 Beta Motor RX 300 lists a 940 mm seat; the Yamaha YZ125 lists 935 mm — a 5 mm difference. 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.
On seat height alone, the Yamaha YZ125 has the easier modeled ground reach. Load your measurements into the simulator to compare the model, then verify both motorcycles in person.
Geometry snapshot
| Spec | Beta Motor RX 300 | Yamaha YZ125 |
|---|---|---|
| Seat height | 940 mm | 935 mm |
| Wheelbase | 1,488 mm | 1,450 mm |
| Wet weight | - | - |
| Displacement | 293 cc | 123 cc |
Posture metrics
Knee angle
- Beta Motor RX 300
- Sport (58.1 deg)
- Yamaha YZ125
- Sport (58.1 deg)
Hip angle
- Beta Motor RX 300
- Neutral (93.2 deg)
- Yamaha YZ125
- Neutral (94.0 deg)
Elbow angle
- Beta Motor RX 300
- Relaxed (143.3 deg)
- Yamaha YZ125
- Relaxed (143.3 deg)
Torso lean
- Beta Motor RX 300
- Neutral (12.6 deg)
- Yamaha YZ125
- Neutral (12.0 deg)