Sunt in culpa qui officia desent mollit anim

A bicycle’s performance, in both biological and mechanical terms, is extraordinarily efficient. In terms of the amount of energy a person must expend to travel a given distance, investigators have calculated it to be the most efficient self-powered means of transportation. In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also a most efficient means of cargo transportation.

Mechanical efficiency

From a mechanical viewpoint, up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels (clean, lubricated new chain at 400W), although the use of gearing mechanisms reduces this by 1-7% (clean, well-lubricated derailleurs), 4-12% (chain with 3-speed hubs), or 10-20% (shaft drive with 3-speed hubs). The higher efficiencies in each range are achieved at higher power levels and in direct drive (hub gears) or with large driven cogs (derailleurs).

Energy efficiency

A human being traveling on a bicycle at 16–24 km/h (10–15 mph), using only the power required to walk, is the most energy-efficient means of human transport generally available. Air drag, which increases with the square of speed, requires increasingly higher power outputs relative to speed, power increasing with the cube of speed as power equals force times velocity. A bicycle in which the rider lies in a supine position is referred to as a recumbent bicycle or, if covered in an aerodynamic fairing to achieve very low air drag, as a streamliner.
On firm, flat ground, a 70 kg (150 lb) person requires about 60 watts to walk at 5 km/h (3.1 mph). That same person on a bicycle, on the same ground, with the same power output, can travel at 15 km/h (9.3 mph) using an ordinary bicycle, so in these conditions the energy expenditure of cycling is one-third of walking.

Typical speeds

In utility cycling there is a large variation; an elderly person on an upright roadster might do less than 10 km/h (6.2 mph) while a fitter or younger person could easily do twice that on the same bicycle. For cyclists in Copenhagen, the average cycling speed is 15.5 km/h (9.6 mph).
On a racing bicycle, a reasonably fit rider can ride at 40 km/h (25 mph) on flat ground for short periods

Reduction of weight and rotating mass

There has been major corporate competition to lower the weight of racing bikes in order to be faster uphill and accelerating. The UCI sets a limit of 6.8 kg on the minimum weight of bicycles to be used in sanctioned races

19 comments

  1. Alexandra

    Hey there I am so thrilled I found your blog, I really found you by accident, while I was looking on Askjeeve for something else, Anyways I am here now and would just like to say thank you for a incredible post and
    a all round enjoyable blog (I also love the theme/design), I don’t have time to look over it all at the moment but I have saved it and also added in your RSS feeds, so when I have time
    I will be back to read much more, Please do keep up the great jo.

    My website; салициловый пилинг

  2. Vallie

    Write more, thats all I have to say. Literally, it seems as though you relied on the
    video to make your point. You obviously know what youre talking about, why waste your intelligence on just posting videos
    to your weblog when you could be giving us something enlightening to read?

    my web site … тредлифтинг мезонитями

  3. Mariana

    Hey There. I found your blog using msn. This is an extremely well written article.

    I’ll make sure to bookmark it and come back to read more of youur useful info.
    Thanks for the post. I will certainly return.
    Bodybuilder web site bodybuilder

  4. Forrest

    I believe what you wrote made a lot of sense. But, what
    about this? suppose you added a little information?
    I mean, I don’t want to tell you how to run your
    blog, but what if you added something to maybe get folk’s attention?
    I mean Sunt fun in phoenix culpa qui
    officia desent mollit anim – The International Society
    of Creatine Kinase Research is kinda plain. You should look at Yahoo’s home page and watch how they write news titles to grab people
    to open the links. You might add a video or a pic or two to
    grab people interested about everything’ve got to say.
    Just my opinion, it might bring your blog a little livelier.

Post a comment

Your email address will not be published.