Davenport 2011 Board Track 1/2-Mile Main Event - Racing starts at 2:00 - C Links.

A brief explaination:
1. These are "early teens" racing bikes (1911 etc). They have only basic front suspension and aside from the inflation pressure in the rear tyre, they have NO rear suspension. They are in fact a motorised bicycle.
2. They are fixed gear (no clutch or gear box) direct drive.
3. They have no brakes. The only speed control is more throttle or none.
4. They are set up for different tracks (gear ratios = different sprockets)
5. They DO go very fast.
6. They are all push start.
7. The start of the race gets underway at ~2:00 - when they push start all the bikes.
8. The riders get going and eventually form a more or less straight line - abreast.
9. This is called a running start.
10. At about 4:22 - you can see the starter with the green flag coming up - and regardless they all start opening up the throttles and really laying the power down, and speeding up.
11. And the flagman (on the left) waved the chequered flag at 8:56 to signal the laps had been done (distance of race) and that this guy was the winner.
12. Then he idles back to the pits.