lanternerouge:

Isn't it to get the riders behind out of your slipstream?

In fact it is the otherway around.  The lead cyclists does this, as it helps to see a pending attack and hopefully be able to react 'pre-emptive', and jump the gun first.  The reason all the cyclists follow and all weave about like a shoal of fish is until *someone* launches an attack, they all try to stay in the slipstream until the last possible moment - and as we know, then all hell lets lose

Nick