Police are appealing for witnesses and one arrest has been made.
Officers were called to Forty Foot Bank, near to the Benwick Road junction, at about 5.30pm on Monday 8 January 2024.
A car had collided with a motorbike travelling in the opposite direction.
The motorcyclist, a man in his 20s, from the Ramsey area, died at the scene.
A man in his 50s, from the Chatteris area, was arrested on suspicion of causing death by dangerous driving.
He has been bailed until 27 March.
Anyone with information or has dashcam footage is being urged to report it to Cambridgeshire Police through the force website using reference 35/1729/24 or by calling 101.
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