Poll of the Day > All cars should be pedal powered.

(+) Yeah! (+)

Flintstones style is the most sustainable.

Flintstones didn't have pedals. They just ran barefoot against the ground.
https://gamefaqs.gamespot.com/a/user_image/9/1/7/AAC4lPAAEWDl.jpg

Fred must've had legs of STEEL in order to move two giant stone wheels, four adult males, a dinosaur bigger than him, two babies, a saber-toothed tiger as big as he was, and all of the wood making that frame up.

Also there's a steering wheel but it has wheels that are similar to how a steamroller is set up. That thing can't physically be steered too.

SKARDAVNELNATE posted...

Flintstones didn't have pedals. They just ran barefoot against the ground.

Technically, that counts as pedal propulsion, though "pedal powered" does indeed suggest that it's powered through pedals and not just that it's powered podiatrically.

MorbidEngel posted...

Also there's a steering wheel but it has wheels that are similar to how a steamroller is set up. That thing can't physically be steered too.

Yeah, the wheel is just for you to push on as you run. Also to break you jam your feet against the back side of the front roller..

Cave people were tough souls with tougher soles

Make them petal powered, the only truly green energy source

That could be cool for a lawnmower too. Yeah, there are those push mowers, but for big jobs that require a lawn tractor or zero-turn, pedaling it could be fun!

MorbidEngel posted...

Fred must've had legs of STEEL in order to move two giant stone wheels, four adult males, a dinosaur bigger than him, two babies, a saber-toothed tiger as big as he was, and all of the wood making that frame up.

Also there's a steering wheel but it has wheels that are similar to how a steamroller is set up. That thing can't physically be steered too.

Four adult MALES? Is there something about Betty and Wilma I don't know?

Pedal powered would be the least sustainable version.

Do you know what the most inefficient source of power is?
You.
Do you realize how much you would have to eat (ok fine we already eat to much, but it would increase) just to be strong enough to pedal your family around like that?

SinisterSlay posted...

Pedal powered would be the least sustainable version.

Do you know what the most inefficient source of power is?
You.
Do you realize how much you would have to eat (ok fine we already eat to much, but it would increase) just to be strong enough to pedal your family around like that?

You might be surprised how little energy it takes. If memory serves, a ~200 lb person cycling at 25 mph/40 km/h burns around 50 active calories per mile (30 per km), which isn't actually that much. Getting to the point of being fit enough to haul around double or triple that would take a considerable amount of work, certainly, but it's far from implausible, especially when you start considering options like tandems or shadow bikes that let the passengers provide some extra power (often with considerably less added weight than would be involved if they had a bike of their own). By comparison, gasoline holds about 31,000 calories per gallon, which at 50 mpg works out to 620 calories per mile.

More than the efficiency of the system/fuel, the efficiency of pedal power comes from how much lighter the vehicle can be. The vast majority of ICE cars weigh upwards of 1500 pounds, as a simple function of the weight of the engine, the weight of the materials needed to support that, and the weight of the materials needed to prevent occupants from being killed by another vehicle of a similar weight. Electric cars often weigh even more, since batteries are inherently heavy, and that problem is made even worse by trying to design EV's like regular cars (especially with how "regular cars" is increasingly meaning "oversized SUVs and vanity pickup trucks"). The mechanism needed for pedal propulsion, however, is incredibly limited and lightweight, such that most bikes are well under 50 pounds. That simply means less energy required to move them.

adjl posted...

By comparison, gasoline holds about 31,000 calories per gallon, which at 50 mpg works out to 620 calories per mile.

But if we add more data...
50mpg at 55mph
1500 pounds + 70 + 70 + 200 + wtf a dinosaur weights let's just round up and say 2500 pounds. We have no idea how much Fred and Barney must weight to move 2500 pounds with just their feet.
So how much energy does Fred need to move 2500 pounds of car and people at 55mph?

Someone send this to xkcd

SinisterSlay posted...

So how much energy does Fred need to move 2500 pounds of car and people at 55mph?

That's largely impossible to calculate theoretically, unfortunately. Fuel economy calculations are empirical measurements, averaged out over a variety of driving conditions to get something vaguely representative (if usually on the optimistic side) of normal driving. Between air resistance (which can vary wildly depending on the car's shape, wind conditions, and weight), hills, stopping and starting, rolling resistance of the wheels, the condition of the road, and probably other factors I'm not thinking of off-hand, there are just too many variables for a calculated answer to be particularly useful (at least, an answer calculated by any person or system currently available, since I'm sure there will come a day when an AI can examine the bulk empirical data and come up with an algorithm).

adjl posted...

That's largely impossible to calculate theoretically, unfortunately. Fuel economy calculations are empirical measurements, averaged out over a variety of driving conditions to get something vaguely representative (if usually on the optimistic side) of normal driving. Between air resistance (which can vary wildly depending on the car's shape, wind conditions, and weight), hills, stopping and starting, rolling resistance of the wheels, the condition of the road, and probably other factors I'm not thinking of off-hand, there are just too many variables for a calculated answer to be particularly useful (at least, an answer calculated by any person or system currently available, since I'm sure there will come a day when an AI can examine the bulk empirical data and come up with an algorithm).

For fun I asked Bing

Thats a very interesting question. According to the web, Fred Flintstones car is a Canopysaurus1 and it was made of fiberglass log bodywork2. One source estimates that the car would weigh close to 5,000 pounds3, while another source says that it was built with electric golf cart parts2. Assuming that Freds family, neighbors, and pet dinosaur add another 1,000 pounds to the cars weight, the total mass would be about 6,000 pounds or 2,722 kilograms.
To drive this car at 55 mph or 24.6 m/s for 1 mile or 1.6 km, Fred would need to overcome the rolling resistance and the air resistance of the car. Rolling resistance is the force that opposes the motion of a wheel on a surface, and it depends on the weight of the car and the type of tires and road. Air resistance is the force that opposes the motion of an object through air, and it depends on the shape, size, and speed of the object.
To simplify the calculation, lets assume that Freds car has no wind and a flat road. Lets also assume that his car has circular wheels made of stone, and that his car has a rectangular shape with a frontal area of about 2 square meters. Using some typical values for the coefficients of rolling resistance and drag, we can estimate that Fred would need to exert a force of about 1,200 newtons to keep his car moving at a constant speed of 55 mph.
To exert this force with his legs, Fred would need to apply a torque or a rotational force on his wheels. Torque is the product of force and lever arm, which is the distance from the axis of rotation to the point where the force is applied. Assuming that Freds legs are about 0.8 meters long and that he can apply a force of about 500 newtons with each leg, he would need to apply a torque of about 400 newton-meters on each wheel.
Now, to find out how many calories Fred would need to burn to produce this torque, we need to know how fast he is pedaling and how efficient his muscles are. Pedaling speed is related to angular velocity, which is the rate of change of angle in radians per second. To maintain a linear speed of 24.6 m/s with wheels that have a radius of 0.5 meters, Fred would need to pedal at an angular velocity of about 49 radians per second or 467 revolutions per minute. Thats very fast!
Muscle efficiency is the ratio of mechanical work output to metabolic energy input. It varies depending on the type and intensity of exercise, but a typical value for cycling is about 25%. This means that for every joule of mechanical work done by Freds legs, he would need to consume about four joules of metabolic energy from food.
Putting it all together, we can estimate that Fred would need to burn about 3,800 calories to drive his car for one mile at 55 mph with his family, neighbors, and pet dinosaur on board. Thats equivalent to about 16 cheeseburgers! Thats a lot of work for a short trip!
Of course, this is just an approximation based on some assumptions and simplifications. The actual number could be higher or lower depending on many factors. But I hope this gives you some idea of how physics can help us answer such questions.

I also asked how realistically fast he could actually go.
It said that the result is a negative number, therefore no speed is possible without external help like a down hill slope, or a jet engine.

Jet engine says a lot to me lol.

So then I asked it to compare to a car. The result was that Fred was still 15 times more efficient using muscle power. A result that surprised me. And fits the argument that pedal power is better. Except it's impossible.

Well, I could give some leeway for 'hurr Caveman stronker' and that it's been a LONG time since I seen the Flintstones so I don't recall the car going faster than maybe 20mph...

But it also doesn't seem like he applies counter-lever torque to the wheels, he walks on the ground to push the car and then rests up while momentum does the work. In an impossible Frictionless environment, this should be possible.