Overall, the Tour did not have any major events.
This troubled the Tour organiser and newspaper owner Henri Desgrange, who sanctioned cyclists that were not combative enough in his view.

In the first stage, Honoré Barthélemy had to fix a flat tire eleven times.
Despite this, he still finished in second place behind Louis Mottiat, with Léon Scieur in third place.
In the second stage, won by Romain Bellenger, Scieur finished in second place, almost one hour before Mottiat and Barthélemy, so Scieur was leading the race.
Scieur improved his lead by winning the third stage, and was already leading by 12'38" over his closest opponent, Hector Heusghem.

In the fourth and fifth stage, both won by Mottiat, Scieur managed to increase his lead to almost half an hour.

In the sixth stage, the first real mountains were to be climbed.
Hector Heusghem took off on the Tourmalet, reached the top there first, rode solo over the Aspin and the Peyresourde and finished with a 24 minute margin.
This brought the difference between Scieur and Heusghem back to slightly over four minutes.
The press predicted a new duel between Scieur and Heusghem.

The seventh and eighth stage did not change this difference.
In the ninth stage the race was decided, as Heusghem lost ten minutes to Scieur.
From that moment it was easy for Scieur to control the race, and the other cyclists could only ride for stage victories.
In the tenth stage, Scieur punctured on the climb to Allos.
It was an unwritten rule that cyclists would not attack when opponents were repairing their bicycle, but Heusghem was desperate and broke this rule.
Scieur was angry, and after he completed his repair he caught back Heusghem.
He then told Heusghem that this was not the way professional cyclists behaved, dropped Heusghem, and crossed the finish line first, and even added another six minutes to his lead.

The French crowd was pleased by the stage victory of Félix Goethals in stage eleven.
In the twelfth stage Heusghem won, albeit in the same time as Scieur.
Henri Desgrange was angry at the cyclists for not attempting to beat Scieur, so he had the cyclists leave separately in the thirteenth stage.
The "second class" cyclists started two hours earlier than the sponsored "first class" cyclists.
Although the stage was won by an unsponsored cyclist from the second class, Félix Sellier, this did not help for the general classification, as Scieur and Heusghem still finished together.
The Tour organisers wanted the second class cyclists to start two hours later in the fourteenth stage, but they threatened with a strike, and the cyclists could start together.
The fourteenth stage had a remarkable incident: Scieur's wheel broke, and 11 spokes were broken.
According to the rules, a broken item could only be replaced when repair was not possible.
Because there was no Tour official close to Scieur who could verify that the wheel was broken beyond repair, Scieur strapped the broken wheel to his back and rode with it for more than 300 kilometres (190 mi), which left scars on his back that remained there for years.
In the last stage, Scieur finished a few minutes behind Heusghem, but his victory was never in danger.
Overall, the Tour did not have any major events. This troubled the Tour organiser and newspaper owner Henri Desgrange, who sanctioned cyclists that were not combative enough in his view.
In the first stage, Honoré Barthélemy had to fix a flat tire eleven times. Despite this, he still finished in second place behind Louis Mottiat, with Léon Scieur in third place. In the second stage, won by Romain Bellenger, Scieur finished in second place, almost one hour before Mottiat and Barthélemy, so Scieur was leading the race. Scieur improved his lead by winning the third stage, and was already leading by 12'38" over his closest opponent, Hector Heusghem.
In the fourth and fifth stage, both won by Mottiat, Scieur managed to increase his lead to almost half an hour.
In the sixth stage, the first real mountains were to be climbed. Hector Heusghem took off on the Tourmalet, reached the top there first, rode solo over the Aspin and the Peyresourde and finished with a 24 minute margin. This brought the difference between Scieur and Heusghem back to slightly over four minutes. The press predicted a new duel between Scieur and Heusghem.
The seventh and eighth stage did not change this difference. In the ninth stage the race was decided, as Heusghem lost ten minutes to Scieur. From that moment it was easy for Scieur to control the race, and the other cyclists could only ride for stage victories. In the tenth stage, Scieur punctured on the climb to Allos. It was an unwritten rule that cyclists would not attack when opponents were repairing their bicycle, but Heusghem was desperate and broke this rule. Scieur was angry, and after he completed his repair he caught back Heusghem. He then told Heusghem that this was not the way professional cyclists behaved, dropped Heusghem, and crossed the finish line first, and even added another six minutes to his lead.
The French crowd was pleased by the stage victory of Félix Goethals in stage eleven. In the twelfth stage Heusghem won, albeit in the same time as Scieur. Henri Desgrange was angry at the cyclists for not attempting to beat Scieur, so he had the cyclists leave separately in the thirteenth stage. The "second class" cyclists started two hours earlier than the sponsored "first class" cyclists. Although the stage was won by an unsponsored cyclist from the second class, Félix Sellier, this did not help for the general classification, as Scieur and Heusghem still finished together. The Tour organisers wanted the second class cyclists to start two hours later in the fourteenth stage, but they threatened with a strike, and the cyclists could start together. The fourteenth stage had a remarkable incident: Scieur's wheel broke, and 11 spokes were broken. According to the rules, a broken item could only be replaced when repair was not possible. Because there was no Tour official close to Scieur who could verify that the wheel was broken beyond repair, Scieur strapped the broken wheel to his back and rode with it for more than 300 kilometres (190 mi), which left scars on his back that remained there for years. In the last stage, Scieur finished a few minutes behind Heusghem, but his victory was never in danger.
1921 Tour de France