motocross / default rider 183 cm
Beta Motor RX 300 vs Yamaha YZ125 ergonomics
Beta Motor RX 300 and Yamaha YZ125 land within a few ergonomic points for the default rider, so the better choice comes down to posture preference and bike category.
Fit verdict
Beta Motor RX 300
All contacts reached
Yamaha YZ125
All contacts reached
The two bikes are close enough that posture preference matters more than the overall score.
Rider fit: reaching the ground
The Beta Motor RX 300 has a 940 mm seat; the Yamaha YZ125 sits at 935 mm — a 5 mm difference. As a rule of thumb you flat-foot a bike when your inseam roughly matches its seat height: about 94 cm for the Beta Motor RX 300 and 94 cm for the Yamaha YZ125.
That makes the Yamaha YZ125 the easier reach to the ground — the safer pick for shorter riders or anyone who wants both feet planted at a stop — while the Beta Motor RX 300 gives taller riders more legroom and a more open knee bend. Load your own height and inseam into the simulator to see exactly how each one fits you.
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)