Those damn cyclists again!

UCDVet

Grandpa Hassan wrote: »

Missed a few pages of this thread, to come back and find people genuinely trying to argue that cycling is no more environmentally friendly than driving. Are these people serious!!?? ��

Seem to be using the most fuel efficient car going (forgetting that it's in slow moving traffic so incredibly inefficient) and forgetting that the driver has to eat as well.

So their argument is that a perfectly efficient car driven by a driver who never eats any food ever is more efficient than a cyclist who has to fuel the seemingly thousands of calories that it takes to cycle the 4 or 5 miles to work.

Joke of an argument

You probably missed the posts where I explained these things, and provided links and what not.

No worries.

Rest assured, nobody is claiming that drivers don't eat, or that it takes thousands of calories to cycle 4 or 5 miles to work.

papu

UCDVet wrote: »

It's cool that you ran the numbers but you need to go a little further...

Yes - you are right. It DOES take more energy to move a car than it takes to move a bicycle. And that makes sense, people intuitively accept this. A bicycle is small and light.

But where does the fuel for each come from? And what is the environmental impact (CO2) of the fuel.

The person eats food.
The car takes petrol.

http://www.scribd.com/doc/24163/CO2-Emissions-of-Foods-and-Diets
Depending on the diet , the CO2 per calorie varies a lot. It's never zero.

And you can use sites like this to see the CO2 impact of the fuel the car uses.
https://www.eta.co.uk/2010/02/22/calculating-a-cars-co2-emissions-from-its-mpg/

Do the math. For a fuel efficient car, it comes down to what the person's diet consists of. Vegetarians - they are very green. Meat eaters....not so much. A 'typical western diet' means the cyclist is worse than the driver. But that assumes a fairly efficient car.

The amount of assumptions are overwhelming and you're leaving out so many other variables like the co2 produced in the oil and coolants and spares used in maintain a car . the food the mechanics eat when servicing the car ...

Either way you've crunched your numbers wrong , 900kcal for 25km = 36kcals per1km . .. So this is the number you want to use in that big confusing spreadsheet you posted ..

Cars produce 169g co2 per km .

So according to that big co2 food table you posted everything under about 4.7gco2/kcal is fair game ..

Also Luckily here in Ireland cattle are grass not grain fed

This also assumes the driver is a robot and consumes no calories as they drive the car which is definitely not true .
And that the car gets 40mpg .. Which again is optimistic and going to be rarely the case

Look this has been fun proving you wrong but just accept that you've come to a Cul de sac and give up this ridiculousness

UCDVet

looking_around wrote: »

You're comparing

cyclist: food consumption burn
vs
Driver: fuel consumption burn

should be

cyclist food consumption
vs
driver: fuel +food consumption.

, good luck making the numbers match for your argument now.

I'm not sure if you are trolling or are serious - so I'll play along.

Everyone uses energy, all of the time. No doubt about that. Sitting in a chair, even sleeping - both the driver and the cyclist are burning calories.

Using the same person, with the same weight and same fitness habits...on two identical days, one where he drives and one where he cycles - he will expend more calories when he cycles.

We're only considering the additional calories consumed by cycling.

Not the base calories that everyone needs to live.

The numbers work out exactly the same either way.

If I need 2000 calories to maintain my weight doing exactly the physical activity I do, and then I throw on a 4-5 mile cycle - I'm going to expend MORE calories. I'd need 2125 calories. We're only considering the difference of 125 calories.

If you want to include all of the calories - it doesn't matter, all things being equal the cyclist will necessarily burn more calories.

Muahahaha

UCDVet wrote: »

When I see people saying things that I wrong, I have a motivation to correct them.

No matter how many times people say it, cycling isn't energy free. It's not CO2 neutral.

Me? Personally....I don't care. I don't own a car, I cycle everywhere. But I do it because I'm too cheap to buy a car. I don't care which is better or worse for the environment.

But the REALITY of the situation is that cycling takes energy. It comes from food. It CAN be less efficient to cycle than to drive. Not sure why people are so desperate to refute this. It's quite obvious and well documented.

I think you're taking the argument to the nth degree and describing outliers from the norm.

The claim that energy needs food to power cycling is fair enough. But to even begin to compare the energy needed to ride a bike and the energy needed to drive a car is spurious. When you take into account that a car has many thousands of parts including rare earth metals and weighs over 1000kgs compared to modern bike which have few parts and weigh 9-12kgs.

And even if food is an input to cycling so what ? It's an input to living too, there are far too many nutritional benefits from eating various foods to say the only thing food is good for is to fuel cycling. It fuels us getting out of bed in the morning, it's pretty essential stuff.

Finally you make no acknowledgement that food is a renewable and sustainable resource. Seeds get produced by plants and crops to produce the following years crop. Oil on the other hand.....

UCDVet

papu wrote: »

The amount of assumptions are overwhelming and you're leaving out so many other variables like the co2 produced in the oil and coolants and spares used in maintain a car . the food the mechanics eat when servicing the car ...

Either way you've crunched your numbers wrong , 900kcal for 25km = 36kcals per1km . .. So this is the number you want to use in that big confusing spreadsheet you posted ..

Cars produce 169g co2 per km .

So according to that big co2 food table you posted everything under about 4.7gco2/kcal is fair game ..

Also Luckily here in Ireland cattle are grass not grain fed

This also assumes the driver is a robot and consumes no calories as they drive the car which is definitely not true .

Look this has been fun proving you wrong but just accept that you've come to a Cul de sac and give up this ridiculousness

I haven't crunched any numbers - please quote where you think I did. Everything I've provided has been linked.

There is no assumption that the driver is a robot and doesn't consume calories.

I think you should take a deep breath....

looking_around

UCDVet wrote: »

I'm not sure if you are trolling or are serious - so I'll play along.

Everyone uses energy, all of the time. No doubt about that. Sitting in a chair, even sleeping - both the driver and the cyclist are burning calories.

Using the same person, with the same weight and same fitness habits...on two identical days, one where he drives and one where he cycles - he will expend more calories when he cycles.

We're only considering the additional calories consumed by cycling.

Not the base calories that everyone needs to live.

The numbers work out exactly the same either way.

If I need 2000 calories to maintain my weight doing exactly the physical activity I do, and then I throw on a 4-5 mile cycle - I'm going to expend MORE calories. I'd need 2125 calories. We're only considering the difference of 125 calories.

If you want to include all of the calories - it doesn't matter, all things being equal the cyclist will necessarily burn more calories.

Except, the majority of people are overweight and are already eating enough calories for their cycle as it is.

You're not taking into account just how much someone is eating even though they aren't doing a 5mile cycle.

like I said, good luck getting numbers to prove cycling is less efficient than cars.

Also, don't forget, majority of people are not driving the most fuel efficient cars, in the most fuel efficient environments.

Tenzor07

Can anyone work out the amount of wasted energy used up by this thread? :rolleyes:

UCDVet

Muahahaha wrote: »

I think you're taking the argument to the nth degree and describing outliers from the norm.

The claim that energy needs food to power cycling is fair enough. But to even begin to compare the energy needed to ride a bike and the energy needed to drive a car is spurious. When you take into account that a car has many thousands of parts including rare earth metals and weighs over 1000kgs compared to modern bike which have few parts and weigh 9-12kgs.

And even if food is an input to cycling so what ? It's an input to living too, there are far too many nutritional benefits from eating various foods to say the only thing food is good for is to fuel cycling. It fuels us getting out of bed in the morning, it's pretty essential stuff.

Finally you make no acknowledgement that food is a renewable and sustainable resource. Seeds get produced by plants and crops to produce the following years crop. Oil on the other hand.....

Food is renewable.
Oil isn't.

Never claimed otherwise?

If someone said, 'I cycle to work so the world's oil supplies will last longer' I'd say, 'Cool'. No argument from me.

Food is necessary to live? Again - agreed - 100%. Never claimed otherwise, and I never claimed the only point of food is cycling.

I've already acknowledge that the manufacturing impact to the environment is HUGE for cars (and huge, but orders of magnitude smaller for bicycles). I've said several times that if you use a bicycle to FORGO owning a car - it's almost certainly a win for the environment.

The specific example that started this was a guy who ALREADY owned a car and ALREADY owned a bicycle. In that situation, riding a few km, instead of driving those same km may not be better for the environment.

That's my argument.

papu

UCDVet wrote: »

The specific example that started this was a guy who ALREADY owned a car and ALREADY owned a bicycle. In that situation, riding a few km, instead of driving those same km may not be better for the environment.

It most certainly is .

looking_around

Tenzor07 wrote: »

Can anyone work out the amount of wasted energy used up by this thread? :rolleyes:

idk, but I'm pretty sure every post has killed a brain cell :pac:

UCDVet

looking_around wrote: »

Except, the majority of people are overweight and are already eating enough calories for their cycle as it is.

You're not taking into account just how much someone is eating even though they aren't doing a 5mile cycle.

like I said, good luck getting numbers to prove cycling is less efficient than cars.

Also, don't forget, majority of people are not driving the most fuel efficient cars, in the most fuel efficient environments.

The amount of food they eat outside of cycling or not cycling doesn't matter though. If you want to say that being overweight is bad for the environment - you'd be right. No argument from me. It's like saying, 'Well, cycling isn't necessarily good, but if they start cycling and stop doing something else that is bad - then it's a win'. Well, sure. But *all other things being equal* is what I'm talking about.

How much someone eats outside of cycling isn't relevant. Just like what other hobbies they have. Lots of things are bad for the environment.

And yes - absolutely, if we talk about fuel inefficient vehicles - cycling looks a lot better (on the flip side - multiple passenger vehicles end up looking even better).

looking_around

UCDVet wrote: »

The amount of food they eat outside of cycling or not cycling doesn't matter though. If you want to say that being overweight is bad for the environment - you'd be right. No argument from me. It's like saying, 'Well, cycling isn't necessarily good, but if they start cycling and stop doing something else that is bad - then it's a win'. Well, sure. But *all other things being equal* is what I'm talking about.

How much someone eats outside of cycling isn't relevant. Just like what other hobbies they have. Lots of things are bad for the environment.

And yes - absolutely, if we talk about fuel inefficient vehicles - cycling looks a lot better (on the flip side - multiple passenger vehicles end up looking even better).

So a cyclist eating 2500cals/day
and a driver also eating 2500cals/day, doesn't come into it, cyclist still eating more?...well ok then.

UCDVet

papu wrote: »

It most certainly is .

Bold clam. No support. I have no reason to believe you.

Explain it to me. If I'm wrong, I'm wrong. I'll apologize for my ignorance.

PeadarCo

looking_around wrote: »

Also, don't forget, majority of people are not driving the most fuel efficient cars, in the most fuel efficient environments.

This is a key point. Bikes can act as a substitute for cars in primarily urban environments and complete journeys quicker than cars. Cars stuck in traffic with the engine on is not efficient.

UCDVet

looking_around wrote: »

So a cyclist eating 2500cals/day
and a driver also eating 2500cals/day, doesn't come into it, cyclist still eating more?...well ok then.

All other things being equal - two identical twins with identical heights, weights, builds and fitness levels....

The twin that cycles will NEED to burn more calories throughout the day.

The only way for them to maintain the same weight is for the cyclist to eat more. Because cycling takes more energy from the rider than driving takes from the driver.

All other things being equal.

Nobody is saying there isn't some fat guy in a car who eats a lot more than he needs.

cython

UCDVet wrote: »

I don't believe I'm overstating anything.

http://bicycleuniverse.info/transpo/energy.html

Eh, looking at the table on that page, if I take my experiences of cycling to work in Dublin, bike is far more carbon-efficient once you're in as far the quays. They default to a city average of 31MPH, which is very optimistic in Dublin at rush hour - typically on the north quays i can average 30+kph and that is faster than most vehicles (barring motorcycles using the bus lane illegally). At those speeds, the bike has a much lower carbon footprint per distance travelled.

UCDVet wrote: »

Cycling is more efficient than walking, *BUT* you also need to consider the manufacturing costs. Building a car has a HUGE negative impact on the environment. Building a bicycle ALSO has a huge negative impact on the environment (but much less than a car).

So, in practice, if you aren't a vegetarian you'd probably be better off buying a fuel efficient car and driving everywhere and NOT having a bicycle. If you buy a car AND a bicycle, swapping out a few miles of car driving with bicycle riding will probably never offset the cost of having the bicycle built.

If you DON'T buy a car - things are different.
If you DON'T eat meat - things are different too.

And if, like me, you have the bike anyway for leisure purposes, and offsetting the cost of the bike is pretty much irrelevant, the equivalent intra-urban journey (as per your own link) is more environmentally friendly done by bike than by single-occupant car (as most of them are, from my observations). You are actually posting sources to refute yourself at this stage, so please stop digging.

qo2cj1dsne8y4k

Are cyclists insured to be using the road

cython

LexieOnRale wrote: »

Are cyclists insured to be using the road

Some are, as has been addressed already in this thread. What relevance does this have when there is no requirement for insurance for cyclists to use the road?

UCDVet

cython wrote: »

Eh, looking at the table on that page, if I take my experiences of cycling to work in Dublin, bike is far more carbon-efficient once you're in as far the quays. They default to a city average of 31MPH, which is very optimistic in Dublin at rush hour - typically on the north quays i can average 30+kph and that is faster than most vehicles (barring motorcycles using the bus lane illegally). At those speeds, the bike has a much lower carbon footprint per distance travelled.

And if, like me, you have the bike anyway for leisure purposes, and offsetting the cost of the bike is pretty much irrelevant, the equivalent intra-urban journey (as per your own link) is more environmentally friendly done by bike than by single-occupant car (as most of them are, from my observations). You are actually posting sources to refute yourself at this stage, so please stop digging.

Nothing you are saying is contradicting anything I'm saying.
Nothing I've posted refutes what I've said.

If you own a bicycle for leisure - great. Enjoy it.

But if you want to claim that it's better for the environment, as a rule, across the board - I'll disagree. For a lot of people cycling can be better for the environment. For a lot of people it ISN'T better for the environment at least in terms of CO2.

Tenzor07

UCDVet wrote: »

For a lot of people, cycling isn't better than driving, in terms of CO2. And compared to public transport it can be much worse.

In your Opinion..

UCDVet

Tenzor07 wrote: »

In your Opinion..

No, it's not my opinion. These are measurable, factual things. Not opinions.

CO2 emissions for the average new car in 2006 were 167.2 g/km
http://www.nextgreencar.com/news/86/Record-low-for-new-car-CO2-emissions
Not an opinion.

For 25km an average car pollutes 4.18 kg CO2.
Not an opinion (basic math)

Using a bicycle takes up energy. On average - something 1.62 kJ/(km∙kg)
http://en.wikipedia.org/wiki/Bicycle_performance#Energy_efficiency
Not an opinion.

Cyclists get energy from food.
Not an opinion.

Food has a CO2 cost.
http://www.scribd.com/doc/24163/CO2-Emissions-of-Foods-and-Diets
Not an opinion.

Using all of these NOT OPINIONs:

Let's assume the rider weighs 80kg, which is below or above average for a male depending on country. Allow 20kg for bike, clothes etc. and we have 100kg. Thus the 25km takes 4050kJ total -- that is 967 kcal

the CO2 equivalent from the extra food needed for cycling would be:

0.068 kg for soy
1.6 kg for chicken
13.4 kg for beef

Again, not opinions, basic math.

For most foods other than pork, beef or lamb, the total energy consumption is below what the car uses. For example, eating only chicken, the bicyclist's total would be 1.75kg, which is significantly less than the car.

The limit where the bicycle pollutes more than the car is if the food creates more than 4.17 g/kcal CO2 equivalents. So the bicyclist can easily afford to eat some beef, if the main energy source is vegetables.

The thing is most people's primary energy source is NOT vegetables.

I have no problem with cyclist (I cycle, don't own a car).
If you enjoy cycling - do it.

But it is not necessarily better for the environment. And that's not my opinion.

PeadarCo

UCDVet wrote: »

No, it's not my opinion. These are measurable, factual things. Not opinions.

CO2 emissions for the average new car in 2006 were 167.2 g/km
http://www.nextgreencar.com/news/86/Record-low-for-new-car-CO2-emissions
Not an opinion.

For 25km an average car pollutes 4.18 kg CO2.
Not an opinion (basic math)

Using a bicycle takes up energy. On average - something 1.62 kJ/(km∙kg)
http://en.wikipedia.org/wiki/Bicycle_performance#Energy_efficiency
Not an opinion.

Cyclists get energy from food.
Not an opinion.

Food has a CO2 cost.
http://www.scribd.com/doc/24163/CO2-Emissions-of-Foods-and-Diets
Not an opinion.

Question what are those averages in an urban environment?, where a bike would be a practical substitute for a car. Longer distances cars make far more sense from a practical point of view alone.

The average you have is 25km for a car. In what enviornment was that average produced? What car was used in calculating this average?.

What's the averages for a car over a 5-10km distance in an urban environment which would a more typical distance where a person may use a bike instead of car? The 25km only makes sense if its calculated on car in an urban environment and stopping in traffic.

Do they take account of the CO2 produced in the oil, new tyres etc for the upkeep of car?

Tenzor07

Seriously, you have WAY too much time on your hands!

You're so far off topic i'd need a telescope to look back on the original thread title!

Anyways, you're still producing your little factoids to push your point...

And sure you'd have to be eating an all-beef diet to offset the environmental benefits of walking or bicycling.

desertcircus

UCDVet wrote: »

No, it's not my opinion. These are measurable, factual things. Not opinions.

CO2 emissions for the average new car in 2006 were 167.2 g/km
http://www.nextgreencar.com/news/86/Record-low-for-new-car-CO2-emissions
Not an opinion.

For 25km an average car pollutes 4.18 kg CO2.
Not an opinion (basic math)

Using a bicycle takes up energy. On average - something 1.62 kJ/(km∙kg)
http://en.wikipedia.org/wiki/Bicycle_performance#Energy_efficiency
Not an opinion.

Cyclists get energy from food.
Not an opinion.

Food has a CO2 cost.
http://www.scribd.com/doc/24163/CO2-Emissions-of-Foods-and-Diets
Not an opinion.

Using all of these NOT OPINIONs:

Again, not opinions, basic math.



The thing is most people's primary energy source is NOT vegetables.

I have no problem with cyclist (I cycle, don't own a car).
If you enjoy cycling - do it.

But it is not necessarily better for the environment. And that's not my opinion.

So a cyclist who goes on 25km+ journeys, outside cities or areas with significant car traffic, while fuelling himself or herself with nothing but red meat? Going by your links and data, that's literally the only case in which cycling is less environmentally friendly - and the number of cyclists who go on long spins fuelled by red meat alone is probably in the single digits.

Tenzor07

desertcircus wrote: »

So a cyclist who goes on 25km+ journeys, outside cities or areas with significant car traffic, while fuelling himself or herself with nothing but red meat? Going by your links and data, that's literally the only case in which cycling is less environmentally friendly - and the number of cyclists who go on long spins fuelled by red meat alone is probably in the single digits.

Exactly, if you eat only the very top of the range Sirloin beef steak does the Vet's argument hold any water...at all.

John_Rambo

100200 shih wrote: »

But I think the money would be better spent on you learning to read better

Learning to read better? For kids that don't read good? Dude, don't forget, you're the one with the problem here, not me! I come up behind cyclists, I toodle along behind then till there's a safe place to overtake, then I check my mirrors, indicate and accelerate around them! Simples! I laugh at people like you veering out, beeping, going nuts in their cars.

I laugh like this: "hahaha ha ha".

Galway Clifton road? Fine road, I'm familiar with it, any competent driver should be able to navigate it with cyclists on it without any hassle whatsoever. If you're getting frustrated and annoyed you need to take an advanced driving course or more likely in your case a few refreshers.

PeadarCo

Tenzor07 wrote: »

Exactly, if you eat only the very top of the range Sirloin beef steak does the Vet's argument hold any water...at all.

I think the point is anyone can set up a hypothetical situation where a car is more efficient and there are plenty particularly when you start upping the distance.

What matters to most people in the real world, is a bike more efficient over journeys where it is a practical substitute for cars i.e. a journey in a large urban area not in a trip from Dublin to Cork.

qo2cj1dsne8y4k

cython wrote: »

Some are, as has been addressed already in this thread. What relevance does this have when there is no requirement for insurance for cyclists to use the road?

There should be, if a cyclist causes an accident who pays for the damages/medical bills/repairs to cars?

Tenzor07

PeadarCo wrote: »

I think the point is anyone can set up a hypothetical situation where a car is more efficient and there are plenty particularly when you start upping the distance.

What matters to most people in the real world, is a bike more efficient over journeys where it is a practical substitute for cars i.e. a journey in a large urban area not in a trip from Dublin to Cork.

Good point..

I think it's quite misleading for someone to say it makes more sense to drive than walk/cycle, if cycling/walking means you need to eat more to replace the energy lost.

papu

LexieOnRale wrote: »

There should be, if a cyclist causes an accident who pays for the damages/medical bills/repairs to cars?

The guilty party .