Good question. I think this makes sense. The distinction between bike and motorcycle should be based on capability. So if you reduce the speed of a motorcycle you could argue that it’s a bike now.
Bicycles go downhill real damn fast. The top speed of a bicycle is largely limited by how foolish the person atop it is and the local geography.
Bicycles can be geared to go across the salt flats real damn fast. The top speed of a bicycle is largely limited by how foolish the person atop it is and the local geography.
Bicycles, even without crazy geography or gearing, can be ridden real damn fast by professionals. The top speed of a bicycle is largely limited by how well-trained the person atop it is. Says Wikipedia:
> The 2025 edition was the fastest Tour de France in history. Tadej Pogačar rode 3,298.6 km in 76h 00m 32s, thus realising an overall speed of 43.4 km/h or 27.0 mph.
Traffic regulations are fundamentally about tail events. Most of the time, vehicular traffic is boring.
The right metric is kinetic energy. But, it'd be unpopular for speed limits to depend upon vehicle mass. Or, in the case of bicycles vehicle and rider mass since the rider mass isn't negligible.
However, that shark is jumped as soon as the classification criteria involve operator-dependent properties like maximum speed of a bicycle. It has no operator-agnostic answer.
So maybe we can enforce that part a little better.
If I tried to drive a car on pedestrian path at even 10kmh I'd be chased by police helicopter and appear on national news.
Coasting down switch-backs at whatever speed the car traffic on the road feels like, and not giving any car incentive to overtake by matching the speeds.
I feel like it's obvious that capability would be measured with a fixed level of user input on a fixed course/dynamo.
I'd wager most weekend spandex warriors could break 100 MPH peak.
Try getting hit by them, you'll feel a pretty big difference. My Zero in a custom riding mode that limits its speed will do way more damage than any e-bike at the same speed.