scooter / default rider 183 cm
Vespa ET4 150 vs Yamaha XMAX 400 ergonomics
Vespa ET4 150 and Yamaha XMAX 400 land within a few ergonomic points for the default rider, so the better choice comes down to posture preference and bike category.
Fit verdict
Vespa ET4 150
All contacts reached
Yamaha XMAX 400
All contacts reached
The two bikes are close enough that posture preference matters more than the overall score.
Rider fit: reaching the ground
The Vespa ET4 150 has a 805 mm seat; the Yamaha XMAX 400 sits at 800 mm — a 5 mm difference. As a rule of thumb you flat-foot a bike when your inseam roughly matches its seat height: about 81 cm for the Vespa ET4 150 and 80 cm for the Yamaha XMAX 400.
That makes the Yamaha XMAX 400 the easier reach to the ground — the safer pick for shorter riders or anyone who wants both feet planted at a stop — while the Vespa ET4 150 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 | Vespa ET4 150 | Yamaha XMAX 400 |
|---|---|---|
| Seat height | 805 mm | 800 mm |
| Wheelbase | 1,280 mm | 1,567 mm |
| Wet weight | - | 210 kg |
| Displacement | 150 cc | 395 cc |
Posture metrics
Knee angle
- Vespa ET4 150
- Sport (57.7 deg)
- Yamaha XMAX 400
- Sport (58.3 deg)
Hip angle
- Vespa ET4 150
- Neutral (97.7 deg)
- Yamaha XMAX 400
- Neutral (91.5 deg)
Elbow angle
- Vespa ET4 150
- Relaxed (143.3 deg)
- Yamaha XMAX 400
- Relaxed (143.3 deg)
Torso lean
- Vespa ET4 150
- Neutral (9.5 deg)
- Yamaha XMAX 400
- Neutral (13.7 deg)