The stunt
Mardi Gras weekend in Soulard, one of the biggest crowds St. Louis puts on a street all year, and a stunt in the middle of it. The stunt gets chosen with the hosts and sized to the street.
The work
Riding slow. Parade pace is walking pace, and on one wheel slow is harder than fast.
The night
It's daytime, it's loud, and the crowd is already there. This is the one episode where I come to them.
Solve the Jump
Why is it harder to balance slow than fast?
The wheel balances front-to-back with its motor, correcting many times a second. Side-to-side is on the rider, who steers under the fall. At walking pace each steering correction moves the wheel less, so the corrections have to come sooner.
Students time how long they can balance a broomstick on a palm, then a pencil. Shorter falls faster. What does that say about how quickly the wheel has to react?
The physicsA feedback loop: sense the lean, correct, repeat
What gets measured
- Slowest speed held without a foot down
- Corrections per second from the wheel's own sensors
- Crowd noise in decibels at the stunt
What has to be true first
- The hosts and the Mardi Gras organizers say yes
- Barriers between the stunt and the crowd
- No kids inside the stunt zone