[newaccount74]

https://biketips.com/calories-burned-biking/ says I burn ~600kcal to ride 20km.

600kcal is ~200g of bread + 20g of butter. Bread costs about 5€/kg, butter costs 2€ / 250g so 600kcal is roughly 1,25€.

My car uses about 6l gasoline per 100km, current price is ~1,60€ per liter, so 20km need 1,90€ of gasoline.

So if I just eat cheap food riding a bike is cheaper.

If I eat at McDonalds, then 600kcal is a hamburger with medium fries, which costs ~4,50€. Then taking the car is cheaper.

This is quite surprising!

[uoaei]

The costs of sitting idly every time you travel, compared to doing some low-impact cardio over the same distance, for trips shorter than about 3 miles, definitely adds up over the years.

The results looks absurd because the math is ignoring a lot of real-world considerations.

[kiliantics]

There's really no question. Cost of bike maintenance vs car maintenance. Societal cost of road wear due to a huge car vs a tiny bike. Burden on healthcare system, regulation and enforcement for dangerous driving habits. We all pay so much for cars, even when not driving one, when usually a bicycle is perfectly sufficient.

[toast0]

maintenance and road wear are clear winners for bikes being cheaper.

Healthcare burden, I'm not so sure. Even with the massive difference in usage, street car tracks in Seattle cause a lot more healthcare burden to bikers (and pedestrians) than car drivers. There's certainly a benefit from exercise, but bicycling also has more exposure to injury during use, and not all of them are superficial injuries. Add in things like poor form inducing nerve injuries and it looks even worse.

[matsemann]

Thousands are dying directly from car usage ("accidents"). A lot more indirectly from being sedentary, and lots of shortened life spans due to the pollution.

So it's not even comparable. It's probably multiple orders of magnitude better on a societal level to be biking. Even better if we got rid of the cars causing the cyclists to be killed.

[toast0]

There were apparently 454 non-traffic bicycle deaths in 2020[1], compared to 38,824 traffic deaths reported by NHTSA in 2020 [2]. I don't feel like bicycles are doing 1% of the trips in the US, even though they're more than 1% of the deaths. I feel like non-traffic death eliminates car vs bike deaths, but captures the basic idea that bicycles are more immediately risky.

All sorts of terrain issues that are minor for a car are dangerous for a bicycle, especially at higher speeds. Where I live, it's very hilly, so it's hard to go anywhere on a bike without hitting speeds of at least 25 mph at some point on the journey. Mechanical issues, unexpected objects in the road, or errors in piloting at that speed will result in an injury for sure.

[1] https://injuryfacts.nsc.org/home-and-community/safety-topics...

[2] https://www.nhtsa.gov/press-releases/2020-traffic-crash-data...

[toast0]

Found some data on person trips by transportation mode [1] and person miles by transportation mode [2]. Based on that, about 75% of miles are done with car/truck/suv/van, and 0.2% with bicycles; but trips are more balanced, 80% by car/truck/suv/van and 1% by bike.

So I think the fatality rate per trip is probably about the same for bike vs car/etc; but the rate per mile for bikes is significantly higher. It'd be interesting to look at comparable rates from say the Netherlands or another country where bicycling is better positioned.

[1] https://nhts.ornl.gov/person-trips [2] https://nhts.ornl.gov/person-miles

[faeyanpiraat]

You are also 17× more likely to pay the ultimate price if you travel the exact same amount on a bicycle (according to UK stats).

Edit: Source: https://assets.publishing.service.gov.uk/government/uploads/...

[uoaei]

Are you making a point? What is it?

[faeyanpiraat]

The comment I replied to makes the point that bikes are better "no question" from the cost perspective since car maintenance is obviously more expensive.

It is a more complex equation than that..

Probably the hardest variable to quantify is the risk of injury/death.

While I agree it could be better if everyone used bikes, but in the current reality if I choose to ride my bycicle, I'm going to share the road with 2000Kg metal boxes which are sometimes driven by distracted drivers, and I'm not willing to take that risk.

So even if I combine all the costs associated with both options, and bikes are cheaper objectively, it will still be more expensive for me.

[Moru]

But you can't compare the negative impact of one thing to the positive impact of the other vehicle. The bikers get hurt by the cars so that is negative on the car account, not negative on the bicycle account.

[uxp100]

I think bicycle calorie burn calculators are basically just nonsense. 600 calories is a ton to burn for a relatively short leisurely ride. Maybe 5x too much.

I have an older garmin that has told me I have burned 9000 calories in a weekend, and uh, I didn’t. No evidence for that, but I simply don’t believe it. Bicycle tourists would have to have wild food intake to sustain that for weeks.

[newaccount74]

I agree 600kcal is on the high side, but I don't think it's as far off as you think. Most estimates I've seen are between 300-500kcal per hour, depending on effort.

It depends a lot on the bike and on the route. On a road bike going down a straight, flat road wearing lycra 20km/h is zero effort. On a city bike loaded with groceries going through urban environment with a bunch of traffic lights 20km/h average is quite an effort.

[matsemann]

What if the added calorie need comes from rapeseed oil or something really cheap? :D

But I think there's some factors at play here. One is that if I didn't commute to work, I would have to work out some other way to get my daily movement in. So it's not necessarily that I eat more just to bike. I just use that energy to move myself to work instead of on a treadmill going no where.

Another interesting factor is what about electrical bikes? The amount of kWh needed to move a small person vs multiple tonnes of car should make it a huge win.

[woodruffw]

If we do this kind of calculus, it’s probably worth including the expected health costs of not exercising. Especially if your normal meal is a hamburger at McDonalds :-)

[johannes1234321]

Even when just sitting around your body requires energy.

[newaccount74]

I'm pretty sure the 600kcal are what my body burns on top of the base metabolic rate, not the total amount burned in an hour.