In cycling it's a case of more waist, less speed

CYCLISTS, forget the expensive, lightweight new bike this Christmas if you want to go faster on your ride to work. Instead, consider shedding a few kilos.

Over six months, British anaesthetist Dr Jeremy Groves conducted a one-man study, alternating between his new $1500 carbon frame bike and his $80 steel bike, on his 44-kilometre ride to work from Sheffield to Chesterfield.

Dr Groves, writing in the British Medical Journal's light-hearted Christmas edition, wanted to see if he could cut his 55-minute one-way commuting time.

The time difference between the doctor's 9.5-kilogram carbon bike and his 13.5-kilogram steel bike? Virtually nothing.

''I didn't notice a dramatic decrease in commuting time, nor did the cycle computer I had fitted to my new bicycle to record any notably swift journeys,'' Dr Groves wrote after 56 journeys to work (30 on the steel bike and 26 on the carbon) taken between January and July.

Dr Groves would decide which bike to take by tossing a coin. He covered 1302 kilometres on the steel-frame bicycle and 1144 kilometres on the carbon-frame bike.

He concluded after six months of riding that there was no measurable difference in commuting times.

‘‘The average journey time on the steel-frame bicycle was 1:47:48, and the average journey time on the carbon-frame bicycle was 1:48:21,’’ Dr Groves wrote in his slightly tongue-in-cheek article.

And he observed that, while a noticeable reduction in bicycle weight would appear to be likely to make a large difference, the reduction in total weight of both the bicycle and rider was less impressive when taken together.

''A new lightweight bicycle may have many attractions,'' Dr Groves concludes, ''but if the bicycle is used to commute, a reduction in the weight of the cyclist rather than that of the bicycle may deliver greater benefit and at reduced cost.''