scrambler / default rider 183 cm
BSA Motorcycles Thunderbolt vs Yamaha XSR125 Legacy ergonomics
BSA Motorcycles Thunderbolt and Yamaha XSR125 Legacy 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
BSA Motorcycles Thunderbolt
All contacts reached
Yamaha XSR125 Legacy
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 BSA Motorcycles Thunderbolt lists a 815 mm seat; the Yamaha XSR125 Legacy lists 815 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 | BSA Motorcycles Thunderbolt | Yamaha XSR125 Legacy |
|---|---|---|
| Seat height | 815 mm | 815 mm |
| Wheelbase | 1,466 mm | 1,330 mm |
| Wet weight | 185 kg | 140 kg |
| Displacement | 334 cc | 124 cc |
Posture metrics
Knee angle
- BSA Motorcycles Thunderbolt
- Sport (58.1 deg)
- Yamaha XSR125 Legacy
- Sport (57.8 deg)
Hip angle
- BSA Motorcycles Thunderbolt
- Neutral (93.6 deg)
- Yamaha XSR125 Legacy
- Neutral (96.6 deg)
Elbow angle
- BSA Motorcycles Thunderbolt
- Relaxed (143.3 deg)
- Yamaha XSR125 Legacy
- Relaxed (143.3 deg)
Torso lean
- BSA Motorcycles Thunderbolt
- Neutral (12.3 deg)
- Yamaha XSR125 Legacy
- Neutral (10.3 deg)