No rider could win the Tour de France without his team.
The idea that a team works selflessly for its leader, or leaders, is unique to cycling. The other team members are known as domestiques, from the French for 'servants.'
These riders work hard in every stage to protect their team leader. If he punctures they will wait while the team mechanic changes his wheel.
He will then pace the team leader back up to the main field, letting the star man ride in his slipstream, saving him valuable energy. If the leader crashes and breaks his bike the domestique will give him his own machine.
On hot days, domestiques are busy collecting drinks from the team cars following to ferry back to their leaders. The team leaders keep an eye on each other while the domestiques have the job of following the rest.
They will help to pace their team leader through the mountains and endeavour to 'lead-out' their team's sprinter and place him in the best possible position in a mass sprint finish. You'll be able to see this in Team Columbia's work with Mark Cavendish this year, as they engineer him the best chance to strike on the stages that end in a straight sprint.
Their reward for sacrificing themselves for the good of the team leader is a share of the prize money and the glory of being in a successful team.
For most of the day, especially on long flat stages, the race rides in one big bunch known as the peloton, from the French word for 'herd'.
Small groups or individuals may break away in the hope of gaining enough of a lead to take the glory of a stage win. Even though riders in a breakaway are often from rival teams they may agree to work together, sharing the pacemaking. Slipstreaming fellow cyclists saves a huge amount of energy.
But normally the opening few hours of a stage are a wearing-down process building up to a climax in the final hour.
Either a breakaway will succeed, or the peloton will near the finish line bunched together and the stage will be decided in a mass sprint.
The last half-hour of the race can get extremely fast as each team tries to make it impossible for rival teams to get any of their sprinters ahead. And so no-one can leap away from the bunch late on.
Each team wants to get their man to the front of the bunch with 200 metres to go so that he has a better chance of winning. This is another job for the domestiques.
One by one they sacrifice their own chance for victory by leading out the sprint and then swinging aside. This goes on until just one man lies ahead of the team's main sprinter.
He will then barge his way through the remaining riders with the aim of getting his star man to the front. Then he too will pull aside 200 metres from the line and let his team's sprinter battle it out with the other team's big sprinters for the line.
There are two kinds of time trials in the Tour de France: the individual time trial and the team time trial. In both time trials the riders ride special time trial bikes and wear streamlined helmets which reduces wind resistance and helps them go faster.
In the individual time trial each rider races on their own against the clock over a long or short course. The rider who covers the allocated distance in the quickest time wins the stage.
The start order in time trials is the reverse of the result sheet - except for the prologue time trial where the order is established by the race organisers. The riders set off from an elevated starting ramp which enables them to get a flying start.
The riders set off at two minute intervals - this is called a staggered start. In the team-time trial (TTT) each nine-man team races together over a course.
The TTT must be held before the sixth day of the race and the course is run between two linked towns over a distance of 50-60km. The TTT is held before the sixth day to avoid upsetting the balance of teams as they lose riders who retire from the race. This would leave the team leader with no team to help him.
The time for the stage is taken from the fifth rider of the team to cross the line. There is no point in the team leader going ahead on his own or with another strong rider because his time will always be the same as the fifth man to finish.
The best teams do particularly well in the TTT and share the pace-making, finishing together. Only riders who fall or have mechanical trouble are left behind. Some lesser teams may only finish with five riders!
These poor stragglers are left to struggle on and try to finish within the day's time limit. While the flat stages can be fast and furious with dramatic sprint finishes the Tour de France is almost always won and lost in the mountains. It is here, in the daunting peaks of the Alps and Pyrenees that a team leader with a chance of winning overall can gain time over his rivals.
On some stages the finish may be at the top of a mountain; on others the mountains are placed earlier in the route with a long, flat road to the finish. Some riders, like the late Marco Pantani who won the race in 1998, are expert climbers and try to gain time by breaking away in the high mountains.
The little Italian used his strength in the mountains to gain more time than he expected to lose in the time trials, which were his weakness. Other Tour winners, like Spain's Miguel Indurain, who won an incredible five consecutive Tours from 1991-95, were strong time triallers.
He would limit his losses in the mountains, hoping to recover the time lost in the time trials. Current Tour champion Lance Armstrong, who won a record-breaking sixth Tour in a row in 2004, is a talented all-rounder.
He will expect to gain time over his rivals in both the time trials and the mountain stages. Armstrong is renowned for his attention to detail in preparing for the Tour each year and focuses his entire season on winning this one race.
The American practises riding important climbs in the mountains many times over in the months leading up to the race. This gives him a big advantage over his rivals.
