Two men were taken to hospital on Monday after being involved in mountain bike crashes in bushland at Ourimbah.
The Westpac Rescue Helicopter took a critical care team to the scene about 11.30am after a report of an injured rider.
The 40-year-old man was taken from the bush in a four-wheel-drive and stabilised at the scene.
He was then air-lifted to John Hunter Hospital with suspected head injuries.
Meanwhile a second rider, who was involved in a separate crash nearby around the same time, was taken by road ambulance to hospital with possible fractured ribs.
