Does owning a lightweight carbon fibre bike cut down your commuting time? Contrary to expectations, a trial carried out by anaesthetist Dr Jeremy Groves from the Chesterfield Royal Hospital in the UK suggests that cyclists should pay more attention to the weight of the rider than the bike!
Writing in the 2010 Christmas edition of the British Medical Journal, the author documents a comparison between the time taken to complete a 43.5 kilometre commute to work using either an older, secondhand steel-framed bicycle bought for £50 and weighing in at 13.5kg, or a new £1000, lightweight 9.5kg carbon-fibre model purchased thanks to a "cycle to work" tax incentive scheme.
Groves compared his performance on each bike over a six month period, determining which bike to use on each day with the toss of a coin. Ultimately, thirty commutes were made on the steel-framed bike and 26 trips on the carbon fibre machine. The journey times were logged with a cycling computer, which clocked up 1144 kilometres over the course of the study.
Surprisingly, despite costing twenty times the price and weighing thirty per cent less, the carbon fibre bike was no faster than the steel-framed model. The top speed achieved - fifty-eight kilometres per hour - was the same on both bikes, and the average journey times were 1h48m21s and 1h47m48s respectively, although times were longer in the winter (owing to winds, heavier clothing and more cautious cycling on the part of the rider). Moreover, the author reports that the ride afforded by the carbon fibre bike was much less comfortable and the fear of falling off is higher in bad weather, leading to longer journeys.
Most importantly, Groves points out that although the thirty per cent reduction in bicycle weight achieved with a carbon-fibre frame sounds like a lot, this difference narrows to just 4% when the combined mass of the bike and rider is considered.
"A new lightweight bicycle may have many attractions, 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."
Only the times you have to carry it up the stairs to your office on the 30Th floor when the elevator was broken. That may be a benefit there, but from what I read of the rider's experience, it may be just for prestige, to own the lightweight machine? An inflated ego would not add weight to a person, would it? maffsolo, Mon, 20th Dec 2010
A carbon fibre cycle may result in a weight advantage when you consider that a normal tubular frame cycle might cost around £200 - £400, whereas a carbon fibre cycle (like this piece of kit) would set you back around £8500. The considerably lighter wallet should make quite a big difference. Whether that would be offset by the inflated ego maffsolo hinted at, I wouldn't like to say. Also, if you had to chain it to some railings, you'd want a pretty heavy gauge chain and padlock, which might rather defeat the object too. Don_1, Tue, 21st Dec 2010
certainly amongst downhill moutain bikers, the greatest amount of surplus weight is attached to their neck...
Is the goal to burn the most fat? Or to have the best riding experience?
It's a problem of diminishing returns. Even if you could reduce the mass of the bike to zero, it's not going to make an awful lot of difference to the effort you have to put in to propel yourself. It's still going to be hard work because of hills and wind resistance.