At around 9.35am, the cyclist – a woman in her 40s – was turning right from B3109 Bradford Road into the entrance road to Wadswick Country Store.
The van behind the cyclist has slowed while she moves to turn, but a silver Mercedes behind the van travelling in the same direction has overtaken the van and struck the cyclist.
The cyclist has been taken to hospital with serious injuries.
The stretch of road remains closed while officers carry out enquiries.
Any witnesses to the collision or anyone who may have dash cam are asked to contact the serious collision investigation team on 01225 694597 quoting log number 68 of today’s date.
Alternatively, they can contact the team directly at [email protected].