this post was submitted on 29 Mar 2024
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I editorialised the title as the original was clickbait, but the video itself is quite good. Interestingly, e-bikes are claimed to have lower emissions than acoustic bikes, although it likely depends on diet (the author didn't specifically compare a vegan diet between the two types but did indicate that vegan + electric is the most carbon efficient form).

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[–] [email protected] 17 points 7 months ago (4 children)

sorry. Im not going to buy that someone with a horrible diet on a standard bike is going to be less environmentally friendly than an e-bike. This is just a smell test thing. I will accept that e-bikes could beat out public trans or such and that some folks might do an e-bike where they won't do a standard one. Including those with bad diets who might not be able to handle to much of a workout and even great in shape folks can go farther or go to places and arrive in a condition appropriate to what they are going to with an e-bike.

[–] [email protected] 6 points 7 months ago (1 children)

Given the immense footprint of certain foods I can believe it.

[–] [email protected] 2 points 7 months ago

yeah but you have to take into account relative effect in how much more of that bad footprint food they will eat vs what they will eat anyway. The difference is minimal.

[–] [email protected] 2 points 7 months ago* (last edited 7 months ago) (1 children)

The arguments between the two certainly can get complex easily. In the end, either option is well ahead of cars and at least in the same ballpark as rail. And I think that's the most important takeaway, that bikes are an incredibly efficient form or transport, and at the least e-bikes are a good option for those where a normal bike would be (or perceived to be) too much effort.

I'll add the video does consider non-carbon environmental related effects to be worse with e-bikes compared to normal bikes, which makes sense because of the battery. But hopefully that will get better over time with the move away from cobalt and other rare earth minerals, and an increase in recycling of batteries.

[–] [email protected] 3 points 7 months ago (1 children)

I agree that the comparison between the two is quite complex (given the many side effects). But I was interested in this question and have done a few back-of-the-envelope calculations on the ongoing CO2 emissions:

Regular Cycling:

  • The caloric consumption of cycling is approximately 2300 kcal / 100 km [1]. Or 2.7 kWh / 100 km.
  • The CO2 footprint of 1 kcal is approximately 1 (vegan) to 3 (meat-heavy) gCO2/kcal [2]. The average is approximately 2 gCO2/kcal.
  • This yields 2.3 kgCO2 / 100 km for a vegan diet and 4.6 kgCO2 / 100km.
    • The result is in the same ballpark as the Guardian article [3] at 2.5 to 3.5 kgCO2/100km.
    • The 96 kgCO2 for production [3] would correspond to 0.5 kgCO2/100km over the 19200km lifetime [3].

(Motor-only) E-bikes:

  • The energy use is about 2 kWh / 100 km (3.3 kWh per 100 miles) [4].
    • But pedal-assisted commuter e-bikes only use 0.7 kWh / 100km (1.1 kWh per 100 miles) [4]??
    • This also seems quite high compared to the 2.7 kWh / 100 km above, given that human muscles are only about 30% efficient [6].
  • With the US carbon intensity (0.368 kgCO2/kWh [5]), this yields 0.736 kgCO2/100km.
    • This result is much lower than the Guardian article [3], probably because it doesn't include manufacturing.
    • The 165 kgCO2 for production [3] would correspond to 0.86 kgCO2/100km over the 19200km lifetime [3].

Based on this, it seems quite plausible that an E-Bike is significantly more efficient than a regular bike, even if the rider is a vegan. But, both are way better than all types of cars and even public transport.

References

[–] [email protected] 1 points 7 months ago (1 children)

again though. the e-bike rider is burning calories while riding. You basically have to add the calories they burned over the time of the commute because the normal cycling riders calories are not calories extra burned but just the calories they burned. So for example from your first link:

"Endurance exercise, like jogging or swimming, for more than 30 minutes can improve your fitness and help you lose weight. Running for half an hour can burn between 250 and 500 kilocalories. Swimming burns between 300 and 400 kcal in the same amount of time, with a front crawl burning up to 450 kcal. "

Needs to add in that sitting 30 minutes burns 66 calories in the example here https://captaincalculator.com/health/calorie/sitting/ They list fidgetting but riding the e-bike will be decently more than sitting in an office chair or car stilly. The variable from your linked article comes out a lot due to weight and extertion level. Bike commuting is usually done at a relaxed pace (unless your late!). I agree though with the top paragraph of @vividspecter

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (1 children)

You're right that the calories burned while riding the E-Bike would also need to be considered. The site you linked gives 220 kcal/hr for "Motor scooter, motorcycle" and 630 kcal/hr for "Bicycling, 12 - 13.9 mph, leisure, moderate effort". This corresponds to 1960 kcal / 100km excess calories for biking (at 75kg weight). Going slower than that (which I certainly don't do ;-) ) somewhat reduces the difference. But then the E-Bike is faster and you somehow have to account for that... I'm sure that people have written scientific publications on such considerations. My napkin math certainly doesn't have that level of rigor.

Overall there's certainly better ways to reduce your CO2 footprint than switching from a bike to an E-Bike. But perhaps E-Bikes are better than their reputation.

[–] [email protected] 1 points 7 months ago

e-bikes have a reputation? Im not claiming they are bad. They are better than any form of transit as far as I know outside of walking and biking. One thing that has not been mentioned is getting excersise is also a general society benefit outside of the strict carbon footprint thing and pollution. Im not sure if public transit could beat it although in my city there is an electric train that does not use batteries so I suppose that might and they are electrifying some busses but the weight makes me wonder if it still could given how light the e-bike is. I keep hoping in the US they will do that tax incentive they abandoned. One thing not related to the article is they tax incentivize electric cars but not bikes but many people simply can't do an electric car because they can't plug it in while an e-bike could be brought in the apartment although usually the batter is removable to charge at your desk or whatever.

[–] [email protected] 2 points 7 months ago (1 children)

Diet is a huge component of most people's footprint. If you start biking 12 hours more a week (how much I would need to if I wanted to switch from my ebike to my acoustic for commuting*), you are going to eat a lot more. If a significant amount of those calories is coming from the standard beef you'd get at a US supermarket, its no surprise you'd be better off using a coal-charged ebike at similar speeds**. So much fossil fuels go into producing that. Tomatoes are worse than chicken apparently though.

*I'm not in good enough to bike at work in under 1.25 hours multiple days in a row and still be in good enough condition to do my job, especially if there are headwinds.

[–] [email protected] 3 points 7 months ago (1 children)

That is just patently false. You will eat slightly more. The majority of everyones calories goes toward keeping your heart beating and existing. It takes an extreme amount of working out to shift that needle and two hours of cycling won't do that. If you have access to a public gym with the equipment that can track calorie burn go see how much it takes to burn 100 calories. Body builders with extreme workouts can double their calorie intake but that is way more than some extra hours cycling. This is why when I did the napkin math I found the standing desk with relaxing over lunch will burn more calories than sitting and walking vigorously during my lunch.

[–] [email protected] 2 points 7 months ago* (last edited 7 months ago) (2 children)

According to my HR monitor, I typically burn about 750-1000 calories/hr when doing cardio exercise for 1 hour. Like, a 3 hour session, I might burn 2400 calories. My basal metabolism when sitting and standing is about 120 calories/hr.

Even with an electric bike, I sometimes burn like 500 calories/hr. During actual bike rides, its more like 700 calories each way.

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (2 children)

Dude man. I think your monitor is off. Burning 1000 extra calories a day is killer. Also intense cardio is way more of a workout than commuting cycling which is more on the level of a brisk walk if that. EDITED - I have been thinking about it and you may be. I will tell you that the typical person will not usual do more than an hour of cardio so you likely may do a killer workout and those are people who work out. Riding a bike on a per mile basis will brun less than a leasurely walk but will burn more on a per time basis. My wife with her ski machine thing burns 100 calories in 20 minutes and that would be with excertion way beyond commute cycling. Likely a person using an e-bike compared to sitting in a climate controled electric car will burn more calories additionally than what they burn on an e-bike compared to a non electric bike just do to temperature, sitting more actively and upright, and exposure to the elements.

[–] [email protected] 4 points 7 months ago* (last edited 7 months ago)

I've used two different brand chest strap monitors (actually, 3, but one was in college spin class many years ago and I don't have any of the data for that, but I used to average zone-4 heart rates with peaks over 210 bps basically every class, so it gives some comparison). With my current one, it seems responsive to everything from sedentary activity to intense cardio. That said, my average heart rate during exercise is above 150 (my most recent 1hr session, my HR rarely dropped below 160bps after the warmup), so the linear relationship between calories and HR no longer holds. So I agree I should take it with a grain of salt, but at least this calculator says at my weight I should be burning over 900 calories if my HR is 150 for 1 hour of exercise. My RHR is like 50, so its not like my HR is just always high either. Still HR-> calories still isn't an exact conversion. A power meter or an O2 exhalation lab would give better info.

Anyways, I agree intense cardio workouts are a lot more than cycling, which was mentioned in my above comment (I only burn about 700 calories/hr commuting vs 750-1000 getting exercise).

The numbers I get from my HR apps are also lower than online calculators for equivalent workouts: they estimate my commute should be 900-1200 calories for my weight and pace (I'm 200lbs/90kgs), not 700 calories. I get to ride on lots of trails, so if not many people are out walking, I don't have as much slowing down/speeding up as someone commuting by roads, and its on a carbon road bike, so that might contribute.

Also, given the length of the commute, I'm not going to go slower than normal recreational bike rides: I just try to avoid doing all-out sprints on the way to work and then the ride on the way home I regularly did all-out sprints during some segments. And even if I went at a more casual pace, the total calories actually wouldn't change that much (maybe 10-15%?). It would of course spread the remaining calories over more time, so the burn rate would be lower.

Burning 1000 extra calories a day is killer.

Which is why I stopped acoustic biking to work and switched to ebike. I would be tired during my shift even after just biking one way. I don't know if I ever biked to work two days in a row: I don't think I could have done my job if I tried that.

[–] [email protected] 1 points 7 months ago (1 children)

Do you even talk about the same units? Sometimes kilocalories get colloquially called calories, but there is a difference of factor 1000.

Here in Germany Coca Cola has on their nutrition list 180kJ or 42kcal per 100ml. That’s 42000 calories for a fifth of a small bottle coke (500ml).

0.5kcal really isn’t much.

[–] [email protected] 1 points 7 months ago

yeah that could be it. Im really not sure when it comes to what these devices throw out. I think its the came calories as what a candybar like lists or that like the average person consume 2000 of them per day for my numbers.

[–] [email protected] 1 points 7 months ago (1 children)

Reading through some sites, 0.5kcal/h seems to be average that when biking leisurely on a normal bike.

700cal/h would mean that you could cycle for 300h with 500ml of coca cola.

[–] [email protected] 1 points 7 months ago

USA uses cal and kcal interchangeably because being confusing with units is our specialty. Guess I should say "Cal" instead of "cal", but no one but chemists care about the difference here. My mistr.