There are many ways that a cyclist might leave a stage race. Some become injured in one of the many avoidable crashes that inevitably happens, others sick and so unsafe to ride with. Others still decide to cut their losses and rest up for whatever is coming next. The saddest, in my opinion, is failing to make the time cut.
The time cut (or hors delais) is a period of time after the first finisher crosses the finish line. Any rider that fails to arrive before the end of that period is cut from the race. (Although in extenuating circumstances, or when a large contingent would go out, race juries can and will reinstate riders.) On flatter, simpler stages, it almost never poses a problem, but move into the mountains and things get tricky. The time cut is a sprinter's bane, coming into play on stages poorly suited to burst energy.
The physical manifestation of the time cut is the broomwagon, a vehicle at the very back of the race tasked with sweeping up any stragglers on the road. When the trackers are off and there's riders still on the course after a stage, it's often a waiting game to see who makes it in ahead, or inside of, the broomwagon.
In one-day races, UCI regulations set the time cut at 8% of the first finisher's time (Regulation 2.3.039) but stage race organisers can do whatever they want (2.6.032) and tend to increase this on more difficult stages. The Grand Tours, which I'll largely be focusing on here, use complex coefficients, tied not only to the stage's difficulty but the average speed of the first finisher, creating a sort of sawtooth pattern. ("So there are situations where both going faster or going slower might decrease the time cut?" Yes! Isn't it fun?)
For your convenience, I have done the maths already. You're welcome.
Thomas Chick
8 May 2023