One of my force-multipliers is the Inmotion V5F monowheel [1]

This is among my favorite devices of all time. It is quick, nimble, and lightweight. It has completely replaced walking, a car or a bicycle for my local trips. While there is a learning curve, unlike a bicycle, it has required almost [2] no maintenance in ~4000 miles of riding, and both hands are free to hold things so I can carry much more than I ever could on a bike. I've transported a desk, groceries, a 50 lb box of firewood, gardening tools, and so on. Plus, riding one is just plain FUN: it feels like skiing or flying. You really have to try it to know.

A pessimistic estimate of the V5F monowheel's efficiency:

* Battery = 320 Wh = 275335 calories

* Weight = 12 kg for the device, so with a rider around 95kg

* Range = 20 km on the low end (25-30 km is typical, manufacturer claims 38±3 km)

Efficiency = 275335 calories / 95000g / 20km = 0.14 calories/g/km

An optimistic estimate given my actual riding experience:

Efficiency = 275335 calories / 91175g / 30km = 0.10 calories/g/km

[1] https://www.myinmotion.com/products/solowheel-glide-2

[2] It still works just fine despite me beating the hell out of it, but the battery has worn down to ~70%

I recently purchased a V10 (25mph max speed) for NYC. It is indeed amazing, but I don't think its accessible to most. You have to have protection gear which can be a nuisance, perhaps after you get confident you can wear less while being conservative in riding. But in general it's not nearly as safe as a bicycle.

Aren't monowheels very nasty when you fall? If it gets stuck you will just flop at high speeds.

Why would you get stuck, though? I'd assume that you can jump off. The high speeds part is risky, but if you don't go fast (15-20km) I assume you should be ok?

Also, they probably aren't even legal to ride.

This fact is the inspiration behind Steve Jobs' idea that computers are bicycles for the mind.

Not that it's a competition, but this is the best answer so far— literally quantifying the force multiplication of bicycles.

"one gram of his weight over a kilometer of flat road at an expense of only 0.15 calories"? That can't be true. I weigh 70Kg, and I'm pretty sure I don't expend 10,000 calories riding a bike for a Km.

The calories we tend to think of aren't the same as the calories that we think we know. In regards to energy intake and eating food, a calorie is actually a kilocalorie. So your 10,000 calories to ride a kilometer is actually 10 kcal.

Unless they meant literally a calorie, not the more common large calorie or kilocalorie. In which case they'd be claiming that 1km ride burned ~10 calories, which is at least at the right order of magnitude. I weigh 73k, and according to my watch I burned 136 calories riding my bike for 6.4km yesterday, for an energy usage of 0.29 calories (not kilocalories) per gram-kilometer.

Calorie is a frustrating unit. When talking about food or exercise, usually we use the kilocalorie but just call it a calorie. I assume the previous poster was using the small calorie. See https://en.wikipedia.org/wiki/Calorie.

So, that seems low to me. I would expect you to burn more than 10 kcal, but it seems the right order of magnitude at least.

> man outstrips the efficiency of not only all machines but all other animals as well

I wonder whether this will still hold true when the costs of building and maintaining

    1. a bike 
    2. a flat road to ride the bike on

is not ignored.

Even better, electric bicycles.

Take all the transportation conveniences a regular bike can without getting sweaty.

bike -> car

https://www.pinterest.com/naturallymitchell/cars/