On Fri, 03 Aug 2012 14:07:12 +0100
Martin Brown wrote:

On 03/08/2012 11:38, Owain wrote:
On Aug 3, 10:07 am, wrote:
Stuff as basic as a bike doesn't need an engine if
you've got legs. A bicycle is almost the most
efficient method of using human power for propulsion.

Rather less efficient than walking, as the weight of the bicycle
also has to be propelled.

Owain

Utterly clueless. The weight of the bicycle makes it very slightly
harder to accelerate, but the rotating wheels make the whole thing
about 3x more efficient than walking. For a given amount of effort
expended an average person can do 15km/h on a bike or 5km/h walking.

See
http://en.wikipedia.org/wiki/Bicycle...rgy_efficiency

At higher speeds wind drag becomes a factor for cycling fast.


Which it doesn't for a walker, unless he is in a strong headwind. I
agree entirely with your argument.
--
Davey.