As a 1st-time watcher of the Tour on TV (I don't have cable/satellite so I only see the weekly summaries for one hour once a week), I don't understand how the time trials work.

What is the purpose of the time trials? Why are they shorter than regular races? Why are riders staggered in start times? How is the starting order determined? How do their race times factor in to the overall race total?

How many of the 21 stages are time trials, and which stages are they?

Typically 2 time trials in each tour (in recent times) additionally the race often starts with a very short TT called a prologue.

The time trial starts at staggered times because each rider rides alone, with no drafting ,against the clock. And each rider is measured on his elapsed time from start to finish

Starting order is inverse to overall race standing , ie. the last rider on general classification goes first, and the race leader goes last.

The TT's are shorter because they are friggin hard with each rider going full out the entire distance, with no drafting allowed. If a TT was the same lenght as a typical road stage, not only would it exhaust the riders, the potential time gain would be so great that it would upset the balance of the race, and potentially make the rest of the race not competitive.

The racer's time for the TT's is added into to the total elapsed time, like any other stage. However the nature of the TT's, with no drafting, tends to produce larger time differentials between the riders.

The time trial starts at staggered times because each rider rides alone, with no drafting ,against the clock. And each rider is measured on his elapsed time from start to finish


Not to be pedantic, but the rider is always measured against the clock, regardless of the stage.

The Prologue is frequently first, as it puts times in the books down to hundredths of a second - whereas in a massed start, riders finishing many places behind the winner (as long as there aren't gaps), all receive the same time. This allows rider place in the GC to be determined based on time, rather than position of finish.

As a 1st-time watcher of the Tour on TV (I don't have cable/satellite so I only see the weekly summaries for one hour once a week), I don't understand how the time trials work.

What is the purpose of the time trials? Why are they shorter than regular races? Why are riders staggered in start times? How is the starting order determined? How do their race times factor in to the overall race total?

How many of the 21 stages are time trials, and which stages are they?

You probably noticed that the TDF has many different stages. The TT have been explained. The TDF is kind of like the Olympic decathalon with several different types of road racing events. The point being to find out who is the greatest all around bike racing athlete. So there are short fast stages called time trials. Long flat stages with group riding. Long rolling stages with group riding and long and very long mountain stages with lots of climbing. The point is to find the rider who can ride the fastest day after day in all of these kinds of races. Since certain kinds of races favor different racer genetics various course profiles are used.

For instance the bigger stronger riders usually can do better at long rolling stages. Guys who are sprinters usually win the long flat stages where they can stay with the peloton and use 20-30 percent less energy than the riders up in the front and then burn everyone else in the last few hundred meters of the race.

Small, strong, lightweight guys with good endurance make the best climbers. They can't win a fast long flat stage but they can ride away from the big guys on multiple long steep climbs.

And of course the TT. They are a test of pure power. Riding at anaerobic threshold for usually 30-55 minutes. 400-500 watt average power output.

Contrast the TDf with the world championships which is a one day road race. Very long with a few smaller climbs. Different kinds of riders will win this race. Usually not the kind that can win the TDF. But some superstar TDF riders can win a race like this.

Okay, now explain the Team Time Trial (TTT), which until recently was a big factor in TdF and still is in many races. ;)

The clock is key but in TT's and tough mtn. stages it is the time to separate yourself from the other GC contenders that is most important. In flat stages barring serious crashes, most GC contenders finish with the same time with very little opportunity to widen a lead or gain time on the leader.

I miss the Team TTs. Those are a thing of beauty.

The TT is called "The Race of Truth" because it's just the rider and the clock.

I so wish they would put the TTT back in.

Fun to watch, but it tends to eliminate a bunch of riders from serious GC contention.

The TTT at Tour de Georgia is held at Road Atlanta (which is anything but flat). Four laps per team. Talk about fun to watch!

Not to be pedantic, but the rider is always measured against the clock, regardless of the stage.

I said in a TT the rider rides against the clock. In a mass start stage, you're obviously timed, but you don't ride against the clock; you ride against your competitors. Thus, you're not trying to go as fast as possible in the least time in a mass start stage, you're trying to finish the stage faster than your competitors, which may well mean riding rather slowly for a good portion of the race.

So I repeat again, in a TT you are racing against the clock; in a mass start race or stage you are racing against your competitors.