Question about track cycling

Could someone tell me what that big red box thing is that they use for these pursuit races on the lead bike at the start?

Is it a sort of wheel clamp that releases when the gun goes?

George

Yes, it's essentially a starting gate. It's connected to the timing system so that the lead rider in events like the team sprint can't go before the gun.

Please though don't ask for an explanation of the Derny bike in the Keirin or about what is happening in a madison. The latter is like quantum mechanics, only understood by two people in this country, and one of them has it wrong.

Thank you for the explanation. I won't ask about the Madison, because it's clear enough from what I've seen that it makes quantum mechanics look like an 11+ exam.