moped / default rider 183 cm
Piaggio Liberty 50 2T vs Yamaha Sirius FI ergonomics
Piaggio Liberty 50 2T and Yamaha Sirius FI 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
Piaggio Liberty 50 2T
All contacts reached
Yamaha Sirius FI
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 Piaggio Liberty 50 2T lists a 775 mm seat; the Yamaha Sirius FI lists 775 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 | Piaggio Liberty 50 2T | Yamaha Sirius FI |
|---|---|---|
| Seat height | 775 mm | 775 mm |
| Wheelbase | 1,330 mm | 1,235 mm |
| Wet weight | - | 98 kg |
| Displacement | 49 cc | 113 cc |
Posture metrics
Knee angle
- Piaggio Liberty 50 2T
- Sport (57.8 deg)
- Yamaha Sirius FI
- Sport (57.6 deg)
Hip angle
- Piaggio Liberty 50 2T
- Neutral (96.6 deg)
- Yamaha Sirius FI
- Neutral (98.8 deg)
Elbow angle
- Piaggio Liberty 50 2T
- Relaxed (143.3 deg)
- Yamaha Sirius FI
- Relaxed (143.3 deg)
Torso lean
- Piaggio Liberty 50 2T
- Neutral (10.3 deg)
- Yamaha Sirius FI
- Neutral (8.8 deg)