A 52-year-old man was left with back injuries and unable to speak after a vicious attack which saw him pushed off a bike.
Colin Flett was found unconscious by paramedics in Skardu Road, Camden, north London at around 11.30pm on July 7.
He was sitting outside the Beaten Docket pub in Cricklewood Broadway when he bought a blue pedal cycle from a man he had never met before.
Mr Flett left on the bike and turned onto Skardu Road where he was set upon by three men who pushed him off the cycle. He cannot remember any more details.
Mr Flett suffered a spinal injury and medical staff assessed him as needing a long period of recovery in hospital.
The attack was not reported until several days later, and Mr Flett spent a number of days unable to speak to his family or police.
Detective Sergeant Richard Greenwood said: “This was a vicious attack that has left Colin with life-changing injuries, in a very vulnerable state, and has had a devastating effect on his family.
“We would urgently ask any person with information, however inconsequential they may think it is, to come forward and pass this to us directly or via a third party.”
The suspects are described as being white and aged between 20 and 30.