The attack followed an incident in which the cyclist and a friend on another bike accused the driver of cutting them up on a road in Neston near Corsham.
The rider fell from his bike and was then assaulted by the well-built driver.
Police are now appealing for witnesses to the incident which happened at around 4.15pm last Tuesday, July 20, but details of which were not released by police until today.
The cyclists had been cycling through Neston towards Westwells when, they said, a man driving a red saloon car cut one of them up.
A police spokesman said: “An altercation ensued which resulted in the cyclist falling from his bike and then being assaulted by the driver.”
The attack took place between the Neston Country Inn and Neston Primary School.
The victim, a 52-year-old man from Bath, received cuts and bruises to his face and a swollen ear.
The driver of the car is described as a white man, approximately 6’2” tall, between 40 and 50 years old, well built, with short fair or grey hair and wearing a light blue t-shirt.
Anyone who witnessed the incident or knows the identity of the driver is asked to contact Heather Osak in the Crime Management Unit at Melksham on 0845 408 7000 extension 728609 or Crimestoppers on 0800 555 111 where information may be left anonymously.