Cycle versus car - false economy?

[roubaixtuesday]

Your assumption is that those who cycle instead of drive eat more than those who drive. But I don’t think that is proven.

Not just not proven, but wildly implausible.

Calorie consumption is a function of metabolism, which is a function of weight and activity.

So in order for cyclists' real world calorie consumption to be increased above non-cyclists by their energy consumption cycling, you'd have to believe cyclists and non-cyclists have the same body mass on average.

I humbly submit that is not the case.

Equally, in order to discount the extra calories consumed cycling entirely, you'd have to believe cyclists don't eat any more at all as a result of their exercise. I humbly submit that this is also implausible, given our legendary capacity for cake.

So I think it's very likely that, on average, cyclists increase their calorie consumption by a fraction of the energy we expend cycling. How big a fraction I could only speculate on.

 

[wafter]

But that cost will reduce as you keep using the bike. How long are you likely to keep it for? Another 500 miles? 5000 miles?

I've done over 5000 miles so far on my £2100 bike, so less than 0.5p per mile on bike cost., though most of those haven't been commuting miles.

I think you'll find your calcs are regrettibly out by a couple of orders of magnitude

 

[Rooster1]

I think about this too, with respect to how much I spend on parts for my bike!

If I drove to work, I would spend £20 a week, or £80 a month on fuel, £960 for the year.

I have to offset the occassional parts purchase of new gears, chain, chainrings, freehub, innertubes clothes - occassionally.

And when the big bills come in, like a new rear wheel for example, the numbers aren't great, but spread over the year, plus the fact I ride for leusire too. I definately don't spend £960 on parts a year though, probably £150 at most. So still £810 better off.

(I bought the bike I use 10 years ago for £700)

I definately don't eat more as a result of cycling.

 

[rogerzilla]

My biggest costs when cycling to work were:

Lots more shower gel, maybe 50p/week
Extra food,maybe £8/week
Extra washing, maybe 50p/week for longer drying in winter (it all goes in with other clothes).
New front brake pads and chain every year for the fixie, about £20/year.
Wear and tear to bike shorts and shoes,maybe £50/year.

Add all that up and you get about £500, which is 2,800 miles in a 40mpg car. It's a 10 mile round trip so, for 260 working days a year, it's cheaper to drive.

But that's not why I did it.

 

[MichaelW2]

You should amortize the cost of purchase over a number of years. 5 years is typical accounting practice. Aftet that ownership costs nothing and maintainance is about £100-200 a year inc club membership, spares. Not counting clothing, which I believe drivers sometimes wear. I also ignore the cost of taking a hot shower and the carbon footprint impact of farts.

Compare to local bus use over 5 years which soon adds up to unaffordable for poor people.

 

[EltonFrog]

But that cost will reduce as you keep using the bike. How long are you likely to keep it for? Another 500 miles? 5000 miles?

I've done over 5000 miles so far on my £2100 bike, so less than 0.5p per mile on bike cost., though most of those haven't been commuting miles.

True, the costs will reduce the more I use it, at some point the investment will go into negative figures and the only on going costs will be consumables.

 

[wafter]

My biggest costs when cycling to work were:

Lots more shower gel, maybe 50p/week
Extra food,maybe £8/week
Extra washing, maybe 50p/week for longer drying in winter (it all goes in with other clothes).
New front brake pads and chain every year for the fixie, about £20/year.
Wear and tear to bike shorts and shoes,maybe £50/year.

Add all that up and you get about £500, which is 2,800 miles in a 40mpg car. It's a 10 mile round trip so, for 260 working days a year, it's cheaper to drive.

But that's not why I did it.

On top of that it's not really a fair comparison as you're counting the cost of consumables / maintenance / other bits for the bike but not the car. For me that £500 would be lost entirely (and more!) on tax, insurance, servicing and MOT.. although how legit the inclusion of these is depends on whether you'd be looking to get rid of the car, and if not what the difference in mileage travelled would be.

Starts to get complicated when you really try to boil it down!

 

[Petrichorwheels]

Your assumption is that those who cycle instead of drive eat more than those who drive. But I don’t think that is proven.

some do I think - witness the bulgings through optimistically race-fit lycra you see on some middle-aged blokes.
Am afraid these energy calculations are a bit beyond me (fled O level science subjects as soon as I could) but I don't see it as a big problem - most folks eat a fair amount of junk which is nevertheless good cycling fuel, and into every life hopefully a bit of eating/drinking for taste only should be done - ditto fuel.
If a car started demanding regular strong pints/peanuts etc I'd get worried and pass it on.
For most things you are better taking the bike for all sorts of reasons.
Like Colin I no longer drive, manage fine with bike and public transport.
The number of cars around and their often minimal practical use horrifies me.

 

[All uphill]

Lies, damned lies and accountancy!

Don't forget the opportunity cost from tying up your money.
Here's my figures
£4000 on a used car or £1000 on a bike.
Buying the bike leaves me £3000 in my savings. At 7% (my average stock market return) that's an extra £210 per year income.

 

[Sea of vapours]

I absolutely do eat more as a result of cycling. My typical daily energy consumption is in the region of a couple of thousand kcalories when doing nothing very energetic. For the 24 hours after a 100+km ride that will be more in the four to five thousand kcalorie range, or even more for particularly long rides. That's a reliable effect which I measured/recorded a few years ago, just out of interest. My mass is stable and generally at, or a little below where I'd like it to be. If I didn't eat a good bit more after cycling I'd shrink, and I don't wish to shrink. It's a really clear, measurable effect for 'long' rides; clearly less obvious for shorter, 'utility' rides, but the energy still has to come from somewhere.

Various comments above about people cycling a given journey not consuming more food than people driving the same journey apply at the population level, but not for a specific individual. i.e. yes, intuitively, the mass of a typical, habitual driver, and hence their basal metabolic rate, is almost certainly a fair bit higher than a typical, habitual cyclist, but that's very much not the point. Taking the specific motorist: if they switch to cycling but don't consume more food they are going to lose weight and reach a new equilibrium at a lower weight. If the cyclist starts driving instead, and maintains their food input, they'll gain weight to a higher equilibrium. This is all a red herring though: what matters is the specific individual, their inputs and outputs and their equilibrium mass.

There is no 'free energy' and there definitely is a marginal cost in energy / food from cycling !

 

[wafter]

some do I think - witness the bulgings through optimistically race-fit lycra you see on some middle-aged blokes.
Am afraid these energy calculations are a bit beyond me (fled O level science subjects as soon as I could) but I don't see it as a big problem - most folks eat a fair amount of junk which is nevertheless good cycling fuel, and into every life hopefully a bit of eating/drinking for taste only should be done - ditto fuel.
If a car started demanding regular strong pints/peanuts etc I'd get worried and pass it on.
For most things you are better taking the bike for all sorts of reasons.
Like Colin I no longer drive, manage fine with bike and public transport.
The number of cars around and their often minimal practical use horrifies me.

Sadly I think I'm one of those.. have been consistently putting on weight and often the immediate hunger post-ride is enabled by the endorphines and feeling of virtue for having got out.

Currently trying to sell the situation to myself as "better fat and fit than just fat", but I'm less than impressed by how things are going tbh.

 

[roubaixtuesday]

There is no 'free energy' and there definitely is a marginal cost in energy / food from cycling !

Sure, but if the individual cyclist ends up thinner as a result then the marginal cost will be less than a calculating not taking that into account would suggest.

 

[Sea of vapours]

Sure, but if the individual cyclist ends up thinner as a result then the marginal cost will be less than a calculating not taking that into account would suggest.

Absolutely; a lower equilibrium is reached. I was addressing assorted comments that asserted, from a variety of positions, that there was zero cost / zero food requirement. Either the equilibrium mass / BMR moves up or down, or the food input changes; not both.

 

[Jameshow]

Not just not proven, but wildly implausible.

Calorie consumption is a function of metabolism, which is a function of weight and activity.

So in order for cyclists' real world calorie consumption to be increased above non-cyclists by their energy consumption cycling, you'd have to believe cyclists and non-cyclists have the same body mass on average.

I humbly submit that is not the case.

Equally, in order to discount the extra calories consumed cycling entirely, you'd have to believe cyclists don't eat any more at all as a result of their exercise. I humbly submit that this is also implausible, given our legendary capacity for cake.

So I think it's very likely that, on average, cyclists increase their calorie consumption by a fraction of the energy we expend cycling. How big a fraction I could only speculate on.

I tend to get slightly fatter if I don't run....

But I get very fat if I don't run or cycle.🤣🤣

I cannot go above 50 miles before needing to eat.

I often don't eat on 40mile rides because I'm trying to burn fat!

 

[roubaixtuesday]

Absolutely; a lower equilibrium is reached. I was addressing assorted comments that asserted, from a variety of positions, that there was zero cost / zero food requirement. Either the equilibrium mass / BMR moves up or down, or the food input changes; not both.

Sorry, misunderstood. I would guess the marginal calorie input is larger than zero but less than the theoretical energy input for a commuter, because they end up thinner.

I wouldn't like to guess by how much.