It happened at 10.34am just south of the Murco garage when a black Kawasaki motorcycle travelling north was in collision with a blue Audi A4 car travelling south.
The motorcyclist, a 37-year-old man from Shoreham-by-Sea, died at the scene.
The driver of the Audi, a 69-year-old woman from Pulborough, suffered minor injuries.
Sergeant Rob Baldwin, of the Sussex Road Policing Unit, said: “I would urge any witness we have not yet spoken with to contact us. We would particularly like to talk to a group of motorcyclists who were travelling northbound on the A29 at Bury just before the collision occurred, and who I believe would have seen what happened.”
Sgt Baldwin added: “The road was closed for six hours while investigation and recovery work took place, and I would like to thank motorists for their patience.”
Anyone with information is asked to phone Sussex Police on 101 or email [email protected], quoting Operation Guardian.