Police have been granted further time to question a 34-year-old man on suspicion of murdering great-granddad Don Lock.
The suspect was arrested 18 hours after Mr Lock was stabbed to death in an alleged road rage incident in West Sussex.
Sussex Police told a press conference they had until midnight on Sunday to question him further.
Mr Lock's son Andrew said his 79-year-old "cycling mad" dad was the "perfect role model".
Sussex Police are hunting a man suspected of killing another after their cars collided