Police are appealing for the driver of a black Honda Civic car which was involved in a collision with a black Harley Davidson motorcycle on the A26 near Budletts Roundabout, Maresfield, near Uckfield, at around 6.30pm on Monday (April 15) to come forward.
Officers also want to talk to any witnesses who may not yet have been in touch.
Both car and motorbike were travelling south on the A26 between its junction with Five Ash Down Road and Budletts Roundabout when they came into contact.
The motorcyclist, a 65-year-old man from Hailsham, sustained muscular injuries and bruising. The car driver continued without stopping.
Anyone who saw what happened or noticed either the motorbike or car being driven shortly beforehand, who may have relevant dash-cam footage or who may have other information is asked to contact police online or by phoning 101, quoting serial 1093 of 15/04.
The driver of the Honda Civic is also being asked to make contact without delay.