Police are appealing for witnesses after a Suzuki motorbike was in collision with a silver Vauxhall Estate on the A18, Barton Street, on Sunday, September 1
The collision occurred at 10.32am on at Wyham, the junction with Salters lane and Lincolngate.
The female rider of the motorcycle, aged in her 40s and from the Newark area, was air lifted to the Hull Royal Infirmary with serious injuries.
The road was closed for a number of hours and was fully re-opened just before 3pm.
Police would like to speak to anyone who witnessed the collision and specifically to anyone who saw a group of four motorcycles travelling together along the A18 towards Louth between 10.10am and 10.30am.
Call the collision hotline on 01522 558855.