This is the shocking moment an angry cyclist attacks an elderly driver with his mud guard before one his friends uses a walking stick to fight back.
The video shows the cyclist throw his bike down to the ground and open the man's car door to launch his vicious assault.
He pummels the driver and shouts a number of obscenities in his direction as a line of traffic on a busy road in Slough, Berkshire draws to a standstill.
At this point one of the elderly man's friends, also in his twilight years, confronts the furious cyclist and after a short discussion raises his walking stick and swipes.
The cyclist then throws a series of punches at the man before a passer-by rushes onto the scene to break them up and take them from the middle of the road, the Daily Mail reported.
But it is still unclear why the fight started.
The man who filmed the incident said it happened at about 12:30pm on Thursday.
Thames Valley Police, who was shown the video by the BBC, said the incident will not be investigated because it hasn't been reported.
"The man who shot the footage asked to remain anonymous and said it was unclear why the fight started," the BBC said.
"We have shown the video to the police and they said the incident had not been reported so would not be investigated."