Britain's flattest city launched a pioneering new ambulance service yesterday - speeding to heart attacks and broken legs on two narrow wheels and 18 gears.

The country's first emergency bicycle tore down the narrow medieval streets of central York to prove that pedal power can be quicker and more efficient than four wheels or even a health authority helicopter.

The experiment's manager, Paul Brown, said: "The bike can get from one side of the walled city to the other much more quickly than a conventional ambulance.

"York lends itself very well to this initiative because there's a big pedestrian area."

The modified mountain bike also has blue flashing lights and extra baskets to carry life-saving equipment, mobile communications and a defibrillator for cardiac victims.

Patients will not, however, be slung over the back of the saddle in cavalry style, but will wait for a back-up ambulance if they need to be taken for hospital treatment. Nicknamed Life Cycle, the experiment is being run for six months by the Tees, East and North Yorkshire Ambulance Service.