The rider was taken to the Forth Valley Royal Hospital, where he later died, following the accident on the Kincardine bypass in Fife yesterday.
Fife Constabulary said the crash involved the bicycle and a black Vauxhall Astra and have appealed for witnesses.
The road was closed to allow for investigations.
Inspector Brenda Sinclair, deputy head of road policing at Fife Constabulary, said: "We are investigating the cause of this crash and I would appeal to anyone who may have seen the black Vauxhall Astra or the pedal cycle, or the immediate aftermath, or anyone who was in this area about 2am this morning to contact the police on 0845 6005702."
l A motorist was killed and a woman badly hurt in a crash involving a car and a lorry on a roundabout yesterday. The male driver of a Honda CRX car was pronounced dead at the scene, on the Clovenstone roundabout on the B701 Edinburgh to Baberton Main Road.