The crash happened shortly before 8.15pm on Old Road at the junction with Ramsey Road, Middlestown between a blue Peugeot 108 car and a SYM 125cc motorbike.
The male motorcyclist was taken to hospital with serious head injuries.
Anyone who may have witnessed the collision, the circumstances leading up to the incident or who may have dashcam footage of the collision is asked to contact West Yorkshire Police’s Roads Policing Unit by calling 101, or go online at www.westyorkshire.police.uk/101livechat quoting reference 13220338415.
