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Bicycles are truly beautiful machines. They are the most energy efficient form of transportation. You can travel pretty long distances with not that many calori

by davidw 4y ago

Bicycles are truly beautiful machines. They are the most energy efficient form of transportation. You can travel pretty long distances with not that many calories.

dheera 4y ago
> They are the most energy efficient form of transportation. If the cyclist is vegan or even an average diet, yes. If the cyclist is paleo, a Prius with 2-person occupancy may actually be more carbon-efficient: https://keith.seas.harvard.edu/blog/climate-impacts-biking-vs-driving https://keith.seas.harvard.edu/blog/climate-impacts-biking-v...
- prmoustache 4y ago
  At equal diet, the bicycle always win. You don't eat significantly more meat because you are using a bicycle to move vs a total couch potato that would use a Prius and eat the same.
  - deleted 4y ago
    [deleted]
  - dheera 4y ago
    I disagree with this. On days I cycle 100km+ in a day I do eat vastly more than if I drive 100km and don't exercise. The energy does have to come from somewhere. If you're only cycling 5km in a day the reason you don't notice the difference in food quantity is because the amount of energy used for that small amount of cycling does not really exceed the amount of energy your body uses in a day for everything else. When you're cycling 100km, it's a different story. It's an interesting question, and in fact the conversion of food to mechanical energy isn't actually very carbon-efficient compared to electricity generation or even gasoline. Cars are actually very efficient at what they do, it's just that what they do (hauling around a 1000kg metal box) is an inefficient way to transport a human, and that's where the inefficiency comes from. If you fill up a large car with full occupancy and go on a long road trip, I'd venture to say it's carbon-wise likely to be more efficient than all of the occupants cycling, regardless of diet.
    - PaulDavisThe1st 4y ago
      This is completely false. See the numbers in the post that for me, right now, is directly below yours: https://news.ycombinator.com/item?id=35345400 https://news.ycombinator.com/item?id=35345400
      - hanoz 4y ago
        The numbers you link to completely fail to take into account the carbon footprint of producing energy in the form of food vs in the form of petrol.
        deleted 4y ago
        [deleted]
        PaulDavisThe1st 4y ago
        Part of the problem is that the former number is wildly variable depending on the type of food, the type of production and the amount of transportation to get it to where it is eaten. Whereas oil-derived fuels are ... well, they vary but not as much. Certainly some food production models (e.g. alfalfa-raised cattle eating for meet thousands of miles from where they are raised) are truly horrible, and may indeed be worse than using fossil fuels. That said, plant-centric, reasonably local food systems that don't use much in the way of synthetic fertilizer generate massively less carbon than any sort of oil production in terms of distance-travelled-per-unit-of-carbon.
        prmoustache 4y ago
        Part of the problem is that people consider that the driver are some aliens that do not eat anything, or stay fit by just following a strict diet and without doing any exercise. But the true reality is most people eat more, make reserves and a huge fraction of the population is either overweight or do physical activities in the purpose of burning those reserves and feel better. Mixing transportation with the later is quite efficient.
    - scott_w 4y ago
- rmvt 4y ago
  if anything this is an argument against the paleo diet and nothing else...
  - dheera 4y ago
    Correct, I wasn't trying to make a statement about specific diets, just that diet does make a huge difference in evaluating the carbon efficiency of cycling.
    - deleted 4y ago
      [deleted]
- loeg 4y ago
  This is definitely the kind of generic tangent / screed I believe to be discouraged here.
- ntonozzi 4y ago
  Perhaps more carbon efficient, but 15x less energy efficient: > Biking takes around 25 kcal/km [iii] above basal metabolism, which is equivalent to .11 MJ/km. A typical car in the US gets 25 mpg, or 9.5L/100 km, which is equivalent to 3.3 MJ/km. The Toyota Prius takes only 5 L/100km, or 1.7 MJ/km. So a typical car takes 30x more energy per kilometer than biking, and a Prius takes 15x more. This is what we expect given how much heavier cars are than bikes.
- scott_w 4y ago
  Not even close to true. I can ride 60-70 miles on reasonably hilly terrain on about 2000kcal. There’s no car that can come close to that. And that’s assuming drivers don’t eat (the McDonald’s wrappers I see by the side of the road proves that they do).
  - dheera 4y ago
    See my comment above with the numbers. 2000 kcal worth of food takes somewhere in the range of 6 kg (for vegetables) to 72 kg (for beef) of CO2 emissions to farm. If you assume a gas car needs 35000 kcal to make the same journey it's about 10 kg of CO2 emissions. You're making a kcal-to-kcal comparison, which is apples-to-oranges in terms of climate change. Climate change doesn't care about kcal, it's greenhouse gases like CO2 that do matter. I know internet forum people are going to come back with a retort about how drivers also eat, but the fact is that cyclists do need to eat more than drivers to make the same journey, and the math puts the answer somewhere in the middle, you need to do the interpolation.
    - scott_w 4y ago
      Your numbers are absolute nonsense. You excluded the CO2 to extract the oil and refine it into petrol/diesel. Nobody eats 2000kcal of beef: that's 6 whole burgers! On top of that, your numbers assume that drivers don't eat, which is self-evidently not true!
      - dheera 4y ago
        > You excluded the CO2 to extract the oil This is miniscule compared to the amount emitted by burning it. It sort of has to be, or the industry wouldn't exist. Congratulations, you're now deliberately fishing at the opposite and and nitpicking at the opposite end just to argue, at this point, when you could be looking at the entire pond. Of course nobody eats 2000kcal of beef, I never said that. I was providing an extremum of all-brassica and all-beef so that you can interpolate somewhere between them, but evidently you're more interested in taking the endpoints and call it nonsense instead of doing the interpolation. So go ahead and assume drivers eat. Bikers eat more. Again, do the interpolation. You get some data, you do the math, then argue. You will still find that it's within the same order of magnitude. CO2 from food production is a thing, and it's hugely variable depending on diet, that's the point.
- olabyne 4y ago
  But the cyclist is doing his required weekly activity. The prius occupants will have to do sport on the side to stay healthy ...
alt227 4y ago
>They are the most energy efficient form of transportation. ...On flat smooth surfaces. On any natural environment or terrain they are nowhere near as efficient as walking.
- PaulDavisThe1st 4y ago
  Not any natural environment or terrain. Modern fat bikes will be more efficient than walking in the scrub desert where I live, in grasslands, in not too dense woodlands, on any kind of open dirt/sand.
  - davidw 4y ago
    I've done 100 mile MTB races, and while it's not as efficient as riding a flat smooth road on a road bike, it's probably still more efficient than walking. Obviously at some point there's a line, where you can't ride a bike, but for most roads and trails, the bike is going to win.
    - PaulDavisThe1st 4y ago
      I think that the comment I was responding to was about scenarios where are no human-created pathways, trails or roads. As I mentioned in some of these, modern fat (tire) bikes are still great; in others, it is true that walking would be the best choice (unless you're at the level of, say, Danny MacAskill).
      - davidw 4y ago
        Sure, fair I guess, but where there are people, there tend to at least be paths. I wonder how many calories MacAskill burns. He makes it seem pretty effortless.
- multjoy 4y ago
  The rest of the world disagrees with that assertion. https://worldbicyclerelief.org https://worldbicyclerelief.org
globular-toast 4y ago
They are the pinnacle of personal transportation technology. Not aware of anything that comes close. I'm not sure how anyone can use a car, keep filling it with more and more fossil fuel and think "yeah, this is good technology".

by davidw 4y ago

Bicycles are truly beautiful machines. They are the most energy efficient form of transportation. You can travel pretty long distances with not that many calories.

dheera 4y ago

> They are the most energy efficient form of transportation. If the cyclist is vegan or even an average diet, yes. If the cyclist is paleo, a Prius with 2-person occupancy may actually be more carbon-efficient: https://keith.seas.harvard.edu/blog/climate-impacts-biking-vs-driving https://keith.seas.harvard.edu/blog/climate-impacts-biking-v...

prmoustache 4y ago
At equal diet, the bicycle always win. You don't eat significantly more meat because you are using a bicycle to move vs a total couch potato that would use a Prius and eat the same.
- deleted 4y ago
  [deleted]
- dheera 4y ago
  I disagree with this. On days I cycle 100km+ in a day I do eat vastly more than if I drive 100km and don't exercise. The energy does have to come from somewhere. If you're only cycling 5km in a day the reason you don't notice the difference in food quantity is because the amount of energy used for that small amount of cycling does not really exceed the amount of energy your body uses in a day for everything else. When you're cycling 100km, it's a different story. It's an interesting question, and in fact the conversion of food to mechanical energy isn't actually very carbon-efficient compared to electricity generation or even gasoline. Cars are actually very efficient at what they do, it's just that what they do (hauling around a 1000kg metal box) is an inefficient way to transport a human, and that's where the inefficiency comes from. If you fill up a large car with full occupancy and go on a long road trip, I'd venture to say it's carbon-wise likely to be more efficient than all of the occupants cycling, regardless of diet.
  - PaulDavisThe1st 4y ago
    This is completely false. See the numbers in the post that for me, right now, is directly below yours: https://news.ycombinator.com/item?id=35345400 https://news.ycombinator.com/item?id=35345400
    - hanoz 4y ago
      The numbers you link to completely fail to take into account the carbon footprint of producing energy in the form of food vs in the form of petrol.
      - deleted 4y ago
        [deleted]
      - PaulDavisThe1st 4y ago
        Part of the problem is that the former number is wildly variable depending on the type of food, the type of production and the amount of transportation to get it to where it is eaten. Whereas oil-derived fuels are ... well, they vary but not as much. Certainly some food production models (e.g. alfalfa-raised cattle eating for meet thousands of miles from where they are raised) are truly horrible, and may indeed be worse than using fossil fuels. That said, plant-centric, reasonably local food systems that don't use much in the way of synthetic fertilizer generate massively less carbon than any sort of oil production in terms of distance-travelled-per-unit-of-carbon.
        prmoustache 4y ago
        Part of the problem is that people consider that the driver are some aliens that do not eat anything, or stay fit by just following a strict diet and without doing any exercise. But the true reality is most people eat more, make reserves and a huge fraction of the population is either overweight or do physical activities in the purpose of burning those reserves and feel better. Mixing transportation with the later is quite efficient.
  - scott_w 4y ago
rmvt 4y ago
if anything this is an argument against the paleo diet and nothing else...
- dheera 4y ago
  Correct, I wasn't trying to make a statement about specific diets, just that diet does make a huge difference in evaluating the carbon efficiency of cycling.
  - deleted 4y ago
    [deleted]
loeg 4y ago
This is definitely the kind of generic tangent / screed I believe to be discouraged here.
ntonozzi 4y ago
Perhaps more carbon efficient, but 15x less energy efficient: > Biking takes around 25 kcal/km [iii] above basal metabolism, which is equivalent to .11 MJ/km. A typical car in the US gets 25 mpg, or 9.5L/100 km, which is equivalent to 3.3 MJ/km. The Toyota Prius takes only 5 L/100km, or 1.7 MJ/km. So a typical car takes 30x more energy per kilometer than biking, and a Prius takes 15x more. This is what we expect given how much heavier cars are than bikes.
scott_w 4y ago
Not even close to true. I can ride 60-70 miles on reasonably hilly terrain on about 2000kcal. There’s no car that can come close to that. And that’s assuming drivers don’t eat (the McDonald’s wrappers I see by the side of the road proves that they do).
- dheera 4y ago
  See my comment above with the numbers. 2000 kcal worth of food takes somewhere in the range of 6 kg (for vegetables) to 72 kg (for beef) of CO2 emissions to farm. If you assume a gas car needs 35000 kcal to make the same journey it's about 10 kg of CO2 emissions. You're making a kcal-to-kcal comparison, which is apples-to-oranges in terms of climate change. Climate change doesn't care about kcal, it's greenhouse gases like CO2 that do matter. I know internet forum people are going to come back with a retort about how drivers also eat, but the fact is that cyclists do need to eat more than drivers to make the same journey, and the math puts the answer somewhere in the middle, you need to do the interpolation.
  - scott_w 4y ago
    Your numbers are absolute nonsense. You excluded the CO2 to extract the oil and refine it into petrol/diesel. Nobody eats 2000kcal of beef: that's 6 whole burgers! On top of that, your numbers assume that drivers don't eat, which is self-evidently not true!
    - dheera 4y ago
      > You excluded the CO2 to extract the oil This is miniscule compared to the amount emitted by burning it. It sort of has to be, or the industry wouldn't exist. Congratulations, you're now deliberately fishing at the opposite and and nitpicking at the opposite end just to argue, at this point, when you could be looking at the entire pond. Of course nobody eats 2000kcal of beef, I never said that. I was providing an extremum of all-brassica and all-beef so that you can interpolate somewhere between them, but evidently you're more interested in taking the endpoints and call it nonsense instead of doing the interpolation. So go ahead and assume drivers eat. Bikers eat more. Again, do the interpolation. You get some data, you do the math, then argue. You will still find that it's within the same order of magnitude. CO2 from food production is a thing, and it's hugely variable depending on diet, that's the point.
olabyne 4y ago
But the cyclist is doing his required weekly activity. The prius occupants will have to do sport on the side to stay healthy ...

alt227 4y ago

>They are the most energy efficient form of transportation. ...On flat smooth surfaces. On any natural environment or terrain they are nowhere near as efficient as walking.

PaulDavisThe1st 4y ago
Not any natural environment or terrain. Modern fat bikes will be more efficient than walking in the scrub desert where I live, in grasslands, in not too dense woodlands, on any kind of open dirt/sand.
- davidw 4y ago
  I've done 100 mile MTB races, and while it's not as efficient as riding a flat smooth road on a road bike, it's probably still more efficient than walking. Obviously at some point there's a line, where you can't ride a bike, but for most roads and trails, the bike is going to win.
  - PaulDavisThe1st 4y ago
    I think that the comment I was responding to was about scenarios where are no human-created pathways, trails or roads. As I mentioned in some of these, modern fat (tire) bikes are still great; in others, it is true that walking would be the best choice (unless you're at the level of, say, Danny MacAskill).
    - davidw 4y ago
      Sure, fair I guess, but where there are people, there tend to at least be paths. I wonder how many calories MacAskill burns. He makes it seem pretty effortless.
multjoy 4y ago
The rest of the world disagrees with that assertion. https://worldbicyclerelief.org https://worldbicyclerelief.org

globular-toast 4y ago

They are the pinnacle of personal transportation technology. Not aware of anything that comes close. I'm not sure how anyone can use a car, keep filling it with more and more fossil fuel and think "yeah, this is good technology".