A cyclist died after being hit by a lorry just before 8.55am on Sunday 18th March 2012.
Andrew Ridsdale, 43, of Mirfield in West Yorkshire was taking part in the Trent Valley 10-mile time trial.
He was in collision with the heavy goods vehicle on the A1 southbound carriageway close to the end of the A634 Spital Road slip road, about one mile south of Blyth services.
The 42-year-old HGV driver was arrested on suspicion of causing death by dangerous driving and later bailed.
Detectives want to hear from anyone who saw the collision or was driving along that stretch between 8.50am and 9am that day.
In particular they think a woman, possibly elderly, who was driven home by someone in a high-visibility jacket - possibly a first aider - may have vital information.
She stopped immediately after the collision and told people at Flo’s Cafe, in a nearby lay-by, she had seen the crash. She was clearly upset by what she had seen.
Anyone with information is asked to call the Crash Investigation Unit on 101, extension 800 2229, or call Crimestoppers anonymously on 0800 555 111.