[LogicHound]

> Pure efficiency in locomotion is a terrible measure, is a person on a bicycle more efficient traversing a forest?

Quite possibly. I would imagine it depends on the forest. I've been in forested areas on the mountain bike and you can cycle through these areas fine.

> It's the classic physics issue - you are ignoring air resistance, but in this case you are ignoring everything other than a perfectly paved road.

Rolling resistance is mainly down to the types of tyres used, how wide they are and how much they are inflated. Surface doesn't make that much of a difference IMO unless it is on a really lose surface e.g. loose gravel, mud or ice.

The biggest improvements to cycling efficiency is usually either being in a recumbent bicycle (less air resistance as you are led down) or by being in a more more Aero position with lycra on. But air resistance only becomes a big thing past 20mph or if you are wearing clothing that is really baggy.

Bicycles are the most efficient forms of transport in energy per mile. They are often the fastest in built up areas as well.

[endymion-light]

"Bicycles are the most efficient forms of transport in energy per mile. They are often the fastest in built up areas as well."

I don't disagree, but if this is the purpose of this graphic, why not just specifically measure different forms of transport in energy per mile?

This article is putting a metric of efficiency, while ignoring the reasons why things like a dog may have less efficent locomotion over perfectly flat terrain, because there are very few natural landmarks that have perfectly flat terrain.

I'd love to see a deeper comparison, how does efficiency of locomotion compare between animals within different types of environments, obstacles, etc. Otherwise this is a graphic that was used to make a point about cycling using an abstract measure rather than actual research.

[LogicHound]

They updated the graphic to include HPV style vehicles that are more aerodynamic than bicycles (usually just a bicycle with an aero-shell). I am not sure why this has come up now because I have an old bicycle book my Grandmother bought for me back in the late 90s that discusses these vehicles and it was known then they were more efficient.

> This article is putting a metric of efficiency, while ignoring the reasons why things like a dog may have less efficent locomotion over perfectly flat terrain, because there are very few natural landmarks that have perfectly flat terrain.

You can't control for this stuff and measure it really.

> I'd love to see a deeper comparison, how does efficiency of locomotion compare between animals within different types of environments, obstacles, etc.

Again this is difficult to control for. Other than particular areas where bicycle won't work (and there are very few places where that would apply), the bicycle is still likely to win out. Even if you have to get off occasionally to navigate over/under/around an obstacle you get all the benefits of efficiency for the majority of the time.

[abakker]

my intuition is that over smoothish, but hilly terrain, mountain bikes fare very well, too, since you get to go downhill for free. once you end up in a talus field, I think it becomes clear that "efficiency" is gone for basically any creature on land.

[ErroneousBosh]

> But air resistance only becomes a big thing past 20mph or if you are wearing clothing that is really baggy.

Can confirm, am 105kg 51-year-old and can get pretty close to 20mph on the flat on my elderly Commençal Uptown. I suspect someone that rode a greater distance per day and weighed about 20kg less would be able to hit 20mph for far longer periods of time.

The further point is that my even more elderly 30-year-old Range Rover can get something like 3mpg better fuel economy on a long run at 50mph than at 70mph. It's genuinely worth getting up at around 4am to drive on deserted roads at 40-50mph to get the back of the journey broken before you start to have to care about keeping up with traffic - just me and the lorries at that time - to get an easy 50-60 more miles out of a tank.

Bicycles are incredibly mechanically efficient because it's basically three sets of taper roller bearings and a chain drive, and chains are insanely efficient. Shaft drive and belt drive sound good, but belts have a lot of friction and shafts require a couple of right-angle gearboxes which are notoriously inefficent. You can make really efficient hypoid gears (that's what's in vehicle differentials, to turn the fore-and-aft propshaft's rotation through 90 degrees, and they're quiet, efficient, and immensely strong) but they require complex cutting curves.

I think that people complaining about the "inefficiency" of bikes are confusing efficiency with effectiveness. A bike would be very efficient at turning power from your legs into motion, but it would not be very effective at transporting two adults, 200kg of tools, and a 3.5 tonne trailer for a couple of hundred miles on road and then a few more up a steep muddy rocky mountain path.

The simple fact that bikes haven't really changed in about a century and a half should tell you how right they got it, straight out the gate. Everything else has been evolution. Take a look at the picture of the 1885 Rover Safety Bicycle on Wikipedia, and tell me you wouldn't quite happily daily that! Okay, you'd be a Hipster Fixie Twat but it would be just right for bimbling round the Finniestoun coffee shops with your ridiculous haircut and Macbook trying to find backers for your AI-powered Cat Food Over IP startup. Me, I'd throw a set of disc brakes and a 5-speed derailleur on, and ride it everywhere.

I genuinely like that frame, actually. I may have to invest in a tube bender.

https://en.wikipedia.org/wiki/Safety_bicycle#/media/File:Rov...