The road was closed for three-and-a-half hours to allow officers to carry out investigations at the scene. Officers would like to hear from anyone who witnessed the collision or saw the motorcyclist prior to it.
Anyone with any information should contact Totton Roads Policing Unit, quoting Operation Froggen, on 101, or the Crimestoppers charity anonymously on 101.
More top news
A court has heard how 13 year old Alexander Worth was killed when a high-performance Ferrari F50 crashed on a farm track in Hampshire.
Monday evening's weather for the west of the region
Monday evening's weather for the east of the region