Emergency services piled into the centre of Dewsbury just before lunchtime today (Monday) to reports of a road accident.
A police spokesman said a cyclist suffered a serious leg injury after falling off his bike in School Street, at the junction with Church Street. No other vehicle was involved.
The air ambulance landed in the car park in Union Street 20 minutes after the incident was reported, but it was not required.
Instead the man, understood to be in his late teens, was taken by road to Pinderfields Hospital in Wakefield.