Bicycle most efficient transportation in the universe?

Question

Scientific American magazine, December 1972, claimed that a human on a bicycle was the most efficient means of transportation in the known universe. Can anyone verify this or direct me to a papyrus copy?

Answer 1

Normally a fair comparison would be the energy used to move a given load a given distance.

As in this link
http://www.exploratorium.edu/cycling/humanpower1.html

This would have been the sort of number crunching that Scientific America magazine would have performed back in 1972.
I have never read the article myself and I haven't been able to find it on-line. I would suggest you check the archive sections of larger libraries for a copy of the article.

Of course a lot of people are going to tell you that the human body is only about 24-25% efficient. If we were to trace back all vehicles to their primary energy source(the sun) I think you will find that the bicycle still stacks up well.

The solar cars take an awful lot of energy to build and have a very limited service life. I would acknowledge that Triple layer Gallium-arsenide solar cells can be >32% efficient and axial flux hub motors around 98%. The aerodynamic drag and rolling resistance is also very low. The energy to manufacture and the operational life are what kills the solar car.

Answer 2

As a mechanical engineer, I would say this is true and not true. In general true.

Because of the diversity of terrain that a bicycle can go over, it is probably the most efficient means for the general case. With an adaption of a trailer, side car, etc, I don't think you can beat a bike.

However, if you look at the weight of a bicycle versus the weight of a ski. You can transport a ski to the top of the mountain more cheaply than a bicycle and under the right conditions a ski is more efficient going down the hill than a bicycle. So in some cases, at some speeds, etc. there might be other forms (i.e. skates, para glider, skateboard) that are more efficient, but the bike rules in most cases.

Answer 3

Efficiency has nothing to do with gravity (PhD, my butt!) or heat produced (the person riding is not part of the machine), and electric motors are AT BEST no more than 75% efficient. In fact, electric motors LOSE efficiency as they spin faster.

Efficiency is measured by how many watts are actually USED for the intended purpose, and in that category a bicycle is, in fact, the most efficient machine ever invented.

Studies have shown that watt for watt, a well-maintained bicycle is up to 98% efficient, with very little energy being lost to friction in the bearings, chain and tires, and the only heat produced is on the contact patch of the tires on the asphalt.

One horsepower = 745 Watts. When I can maintain a 30mph pace on the road using about 200W, or little more than 1/4 HP, just try to compare that to the vehicles using over 100,000 Watts (that's only 134 HP) just to pass me!

Look for a book titled High Tech Cycling. Within it, you will find MANY studies on efficiency, body positioning, aerodynamic properties, watts produced, etc. that should answer your questions.

Answer 4

somebody told me once that energy is technically transfered, not typically created or destroyed and that in theory, the 'speck' of energy can be recycled to produce, perhaps within some limitations, any amount of output for any duration of time ... i don't know the math or the possibilities, but i've alot of faith in that ... building transmissions is everything ... if the whole bus was just a great big 'transmission' that recycles gravity or humidity or anything imaginable, then even the bus can be the most efficient transportation ... some even suggest that for there to be existence, then, because something doesn't appear from nothing, something could only have appeared from something else: indicating infinte something the always was and always will be, just self-recycling forever

Answer 5

The article in question, "Bicycle Technology" was in the March 1973 edition of Scientific American (the one that actually has a bicycle on its cover). It has a graph, plotting weight against cost of transport (measured in calories per gram per kilometre), for various creatures and forms of transport. The bicycle, at 0.15 calories per gram per kilometre, nearly an order of magnitude lower than anything else in terms of efficiency.

Answer 6

In case of pure effectiveness, I don't think that bikes can compeed with modern solar powered cars.
If you strictly compare the watt that goes in versus the weight moved a certain distance, then bikes aren't that effective. Too much drag from the wind, too much excess heat production (watt wastage) in organs and limbs that don't contribute to the forward motion.
My money would be on a modern, longdistance solar powered car, they move under surprisingly small amounts of watts and with extremely small amounts of waste when it comes to energy.

Answer 7

YES....no questions asked---the design, ergonomics, materials of bicycle construction have gone real high tech----scandium, titanium, carbon fiber frames have dominated the frame materials of this great invention! And now the bikes have looked SEXIER! Viva Bicicletas!

Answer 8

Actually, in Popular Science's magazine (Oct. 15th, 2129), the hoverboard is the most efficient means of transportation. Oh no... I shouldn't have said anything

Answer 9

the most efficient method of transportation would be something electric and fast, and doesnt require effort to drive. although bikes get pretty good mileage when you compare output to the amount of water consumed.

Answer 10

No, no copy or anything, just wanted to chip in my two cents....


I LOVE MY BIKE!!!!!