Police are appealing for information after a serious road traffic collision at around 8.45am on Saturday, May 7.
It happened on the B2177 Southwick Road at Southwick northbound between James Callaghan Drive and Pitymoor Lane.
Two pedal cyclists riding together in a group collided leaving one rider, a 61-year-old man, with serious head injuries. He was taken to Southampton General Hospital.
The northbound carriageway remained closed for approximately three hours to allow for the scene to be examined.
Anyone who witnessed the collision should contact the Roads Policing unit at Havant on 101 quoting Operation Enter. Alternatively call Crimestoppers anonymously on 0800 555 111.