Bike thieves are usually content to quietly swipe bikes from the streets, but a South Yorkshire man suffered one of the nastier bike robberies we've come across at the weekend when he was assaulted by a van passenger and then had his bike stolen.

On the afternoon of Saturday November 29, at about 1:35pm, the 34-year-old was riding along Westfield Road, Kirkhouse Green, about 10 miles north-east of Doncaster.

The driver of a white Ford transit van braked heavily in front of him causing him to stop.

A man got out of the passenger side of the van and attacked the rider, punching him in the head and knocking him unconscious to the ground.

The bike, a black Casati Marte, was then stolen.

Casati is not a common brand in the UK, and the Marte is its high-end, custom-built frame, so it's safe to say there won't be many of then about.

A South Yorkshire police spokesman said: "The man who punched the rider is described as white, approximately 5ft 10in tall, of large build with broad shoulders, around 25 to 30 years old. He had brown hair, was unshaven with stubble and had a moustache."

Police would like to speak to anyone who witnessed the robbery or has any information as to the whereabouts of the stolen bike.

Anyone with information is asked to call South Yorkshire Police on 101 quoting incident number 627 of 29 November. Alternatively, call Crimestoppers anonymously on 0800 555 111.