Bikers can be won either by a mile or a centimeter. There's certain techniques bikers use to win a race, and one of them is a bike throw, and this is how you do it.
A bike throw occurs in the final moments of the bike race, usually within the last few feet. A sprint is involved, and at the end of the sprint, the rider pushes his arms forward, stretches his back out, and attempts to move his bike as far forward as possible, getting to the finish line before his competitors.
So when you are first starting to practice how to bike throw, you can start at a slow speed, and extend your arms completely straight, extending your back, extending your shoulders. You can find that the saddle actual moves in front of you with your butt behind the saddle. As you get more comfortable riding, and as you get more comfortable with the bike throw you can do this at quicker and quicker speeds. And you are going to find that it helps you gain a few feet at the end of a bike race.
Timing is incredibly important in a bike throw. You don't want to throw it too early, or you'll lose momentum, and you don't want to throw it too late, or you've already crossed the finish line and it won't even matter. Most bikers in races are going to use the bike throw if it comes down to a very, very tight sprint at the end of the bike race.
You definitely want to practice this. You are going to be going at a really high rate of speed in a bike race, and you want to be very comfortable being able to throw your bike before you try this in a bike race.
And that's how you bike throw.