This is worth reading and helps to make sense of the way the race works -
Customs and traditions at the Tour de France
by Tim Harry
The Tour de France may not at first seem a very ethical sport, and look at sprint finishes and it is certainly every man for themselves.
Also the drug controversies that have followed Le Tour over the last decade have harmed the sporting image of cycling as a whole.
There are though a number of unwritten rules which most riders abide by when taking part in the three week grand tour.
There is a common site during the Tour de France, and indeed many other professional tours, of a single rider leaping from the front of the peloton with no reaction from the rest of the group.
At first glance it may appear to be just another lone rider attempting to gain the glory of a stage win.
There is though an agreement amongst riders that if a stage of the Tour de France goes through, or near the hometown, of one of the riders that they will be able to go ahead and stop and chat with their family and friends.
This though will not happen if that town is near to the finish line, the customs involved in professional cycling though also mean that once given the head start, the rider will then not try and stay ahead of the peloton.
The Yellow Jersey wearer of the Tour de France is given an honoured position, and knows it is unlikely that any of his nearest challengers will mount an attack on the final stage of the tour.
Thus the journey into Paris is one where the soon to be winner of the Tour can take in his achievement. Indeed other than when the final stage of the race is a time-trial, or if you are Pedro Delgado in 1987, the final stage is the most uncompetitive of the whole three weeks.
If one of the leader's of the stage suffers a puncture or other mechanical breakdown, then the peloton slows down, and none of his rivals will attack.
The same goes for when the rider answers the call of nature. No-one attacks either when the feed stations are to hand, this is partially down to the danger involved but also the fact that everyone recognises the need of all cyclists for food and drink during a stage.
One of the most famous examples of sportsmanship within the Tour de France though occurred in 1993 when Lance Armstrong was knocked to the floor by the bag of a spectator. It would have been the perfect opportunity for Jan Ullrich to ride away, win the stage and make up the deficit of fifteen seconds that he had on the America.
Ullrich though did not attack, and instead waited for Armstrong to remount, get up to speed and rejoin Ullrich before he started to cycle again.
There are also others small displays of the unwritten rules by which the Tour de France is governed.
If a rider is part of a breakaway and does no work to ensure its success, then they will not go for the stage win.
The latest example of this was in the 2009 Tour de France when Alberto Contador, Andy and Frank Schleck were together on the 17th stage to Le Grand Bornand. Frank and Andy did the work to ensure the three stayed clear, and thus Contador did not sprint for the finish, which Frank Schleck won.
Of course any unwritten rule can be broken, but it does no good to anger other professional riders, and the peloton never forgets.
Break a rule and the peloton will do its best to ensure that there is no future success for that rider.
Not everyone would agree with all of these Tour de France unwritten rules, but they create a companionship, a sense of belonging that goes far beyond individual teams.