This is the first time I have seen an attempt to compare an e-bike to pedaling! Well done and I think you did a great job with the article. However, I think the approach may be slightly off, thought the correction shouldn't change the overall conclusion. When you calculate the MPG eq of the e-bike, it looks like you are calculating energy efficiency of electricity which is already in usable form. A more fair comparison would be to compare "well to wheel" economy of the energy going into the e-bike to the energy in the food. I think this because the conversion of raw materials (food) for the pedaling case is being accounted for whereas for the e-bike, the conversion of raw material (coal or sunshine or wind or gas for turbines etc) is not being accounted for. In that respect, it isn't a fair comparison at all. If we were comparing efficiencies for on board storage rather than well to wheel, then we should compare onboard stored electricity as you have done to ATP counts (Adenosine triphosphate which is the energy storage molecule in the body). But, at a result of 1000+mpg eq to about 100 mpg eq, I am sure it wouldn't change your overall conclusion. Just some feedback to make sure we are comparing apples to apples rather than apples to ATP :D
Good point. My analysis isn't perfect, but it is in the ballpark and the MPGe calc does let allow a great comparison to electric cars (which was it's initial purpose). The embodied emissions of an eBike battery and motor are less than the embodied emissions of even a single aluminum bike frame so I left them out. To see what's truly possible now check out Mark Havran's solar eBike. He certainly pedals it, but it could go a long way each day on solar alone, and if he doubled the panel size it might be able to go as long as he could stand sitting in it.
Obviously, you wouldn't want to tow a big solar array, but for a commuter bike you could easily mount it on a structure and charge the batteries from it at work, or buy a pair of batteries and always have one charging at home (this would be extra emissions but the batteries would last longer this way and maybe you could use them for other purposes too, like Aventon's new eBike that runs on Worx power tool batteries). It'd be interesting to calculate the total embodied emissions of that and then see how many steaks you'd have to eat to equal it (or potatoes if you want to get a bigger number). I'll leave this as an exercise to the reader :)
Incredibly janky port of comments from my old WordPress site:
Judith Black
2021-05-23 at 12:16 am
Hi, do you know which is the lightest e-bike pout there. As an official old lady who has biked most of her life, would love to graduate to one of these, but would need to lift it for storage, and the old gray mare, she ain’t what she used to be. Thanks.
You can also find your own light weight bike and get a shop to convert it to electric. If you use a small battery and a small motor this can only add a few lbs of weight. Hope this helps!
This was extremely helpful. thank-you. Yes, there is a company in my neck of the woods, GoeOrbital, (MASS) that creates a wheel you can put on your traditional bike that is electrified.
Wow, an eBike conversion company that I hadn’t heard of? Thanks for sharing! Looking at their product it does seem like the easiest to install eBike conversion I’ve ever seen, but I have a few reservations about it.
First, and maybe most importantly for you is the weight. The 700C road bike sized version of their product weighs 21 lbs (https://electricbikeaction.com/amp/product-test-geoorbital-wheel/). Put it on a 30 lb bike and you’re over 50 lbs total with most of the weight in the front making the bike unbalanced. One good thing about their design is that most of their wheel weight is not actually spinning so it’ll have better performance than say the Copenhagen wheel, where all the weight is spinning around (this may be part of the reason why the Copenhagen wheel is no longer sold).
Next, I wonder how true (eg flat) their rim will stay over the years. Regular spoked tires get out of true all the time (you can observe this be spinning an old wheel and seeing how the rim looks wobbly as it passes the brake pad getting closer to it during part of the rotation and further away during the other part). With a spoked wheel a mechanic can return it to true by adjusting the tightness of the spokes (this is almost like tuning a guitar except you want all the spokes to play the same note). If the Geo gets out of true I think it’s just finished, but maybe their orbital engineering never goes out of true? The build videos they posted show the frame to be two thin pieces of folded metal bolted together, so I’m skeptical that it will stay true over the long run.
The final issue I see is the foam filled tires. I’ve long subscribed to the late great Sheldon Brown’s advice on airless tires (https://sheldonbrown.com/tires.html). “They are heavy, slow and give a harsh ride. They are also likely to cause wheel damage, due to their poor cushioning ability. A pneumatic tire uses all of the air in the whole tube as a shock absorber, while foam-type “airless” tires/tubes only use the air in the immediate area of impact. They also corner poorly.”
I can see why Geo had to use airless for their design (the motor would rip off an air nozzle) but they get all these disadvantages because of it. I’d recommend using this tire on a bike with a good front shock to make up for the lack of cushion from the tire, but the internet components of the GeoOrbital itself won’t get any cushioning from the shock, and I wonder how many potholes it will run over before they get broken.
The other problem with a foam filled tire is replacing it’s rubber tread. Sure you don’t have to worry about holes in the tire, but eventually the rubber itself will wear down to nothing and you’ll need a new tread. Unfortunately, since the tread here is glued to the foam and likely the rim as well it’ll mean you need a while new rim filled with foam and rubber. The only place you’ll be able to buy this specialty product will be GeoOrbital itself and who knows if they’ll still be around and making it when you need it. Hopefully they used a very thick rubber in the wheels they produced, but it’ll still need to be replaced eventually.
This is way too much to write about a product that doesn’t even seem to be sold anymore, but it was so unique that the engineer part of my brain really wanted to think about it. The simplest eBike conversion kit that I know of which is actually for sale is the Swytch kit. This whole kit weighs under 7 lbs, so it’ll add far less weight than the geo-orbital and it’s nearly as easy to install. I have heard of people have quality issues with some of the earlier kits they sold, but hopefully after producing many more they’ve worked those out.
For a higher quality motor/battery pairing you could also reach out to Grin Technologies. They don’t make things quite as easy as Swytch but their quality is better and you can end up with an even lighter eBike kit from them if you pick the right stuff. If you’re not an engineer though you might want to find a bike shop near you that will reach out to them for you. Their website does a great job of explaining more about eBike conversions and what to look for in a conversion though (https://ebikes.ca/getting-started/start-here.html).
Lordie, am I impressed by your knowledge and commitment to this technology. Yup, the weight is what put me off of it, but your explanation now flushes out yet more reasons that it would not have been a god choice. many thanks.
Glad it helps. Hopefully you get into a lighter weight eBike either by conversion with a truly light system or by buying one of the ones I messaged about. When you do please leave another comment here, as I’d love to hear about it!
This is the first time I have seen an attempt to compare an e-bike to pedaling! Well done and I think you did a great job with the article. However, I think the approach may be slightly off, thought the correction shouldn't change the overall conclusion. When you calculate the MPG eq of the e-bike, it looks like you are calculating energy efficiency of electricity which is already in usable form. A more fair comparison would be to compare "well to wheel" economy of the energy going into the e-bike to the energy in the food. I think this because the conversion of raw materials (food) for the pedaling case is being accounted for whereas for the e-bike, the conversion of raw material (coal or sunshine or wind or gas for turbines etc) is not being accounted for. In that respect, it isn't a fair comparison at all. If we were comparing efficiencies for on board storage rather than well to wheel, then we should compare onboard stored electricity as you have done to ATP counts (Adenosine triphosphate which is the energy storage molecule in the body). But, at a result of 1000+mpg eq to about 100 mpg eq, I am sure it wouldn't change your overall conclusion. Just some feedback to make sure we are comparing apples to apples rather than apples to ATP :D
Good point. My analysis isn't perfect, but it is in the ballpark and the MPGe calc does let allow a great comparison to electric cars (which was it's initial purpose). The embodied emissions of an eBike battery and motor are less than the embodied emissions of even a single aluminum bike frame so I left them out. To see what's truly possible now check out Mark Havran's solar eBike. He certainly pedals it, but it could go a long way each day on solar alone, and if he doubled the panel size it might be able to go as long as he could stand sitting in it.
Obviously, you wouldn't want to tow a big solar array, but for a commuter bike you could easily mount it on a structure and charge the batteries from it at work, or buy a pair of batteries and always have one charging at home (this would be extra emissions but the batteries would last longer this way and maybe you could use them for other purposes too, like Aventon's new eBike that runs on Worx power tool batteries). It'd be interesting to calculate the total embodied emissions of that and then see how many steaks you'd have to eat to equal it (or potatoes if you want to get a bigger number). I'll leave this as an exercise to the reader :)
https://www.youtube.com/watch?v=7RGBBNctWNA
Incredibly janky port of comments from my old WordPress site:
Judith Black
2021-05-23 at 12:16 am
Hi, do you know which is the lightest e-bike pout there. As an official old lady who has biked most of her life, would love to graduate to one of these, but would need to lift it for storage, and the old gray mare, she ain’t what she used to be. Thanks.
Profit Greenly (Post author)
2021-05-23 at 8:41 pm
Lots of great options for light eBikes. This link shows the absolute lightest out there, but they’re very pricey. https://electrek.co/2021/05/03/this-new-electric-bike-is-one-of-the-lightest-e-bikes-in-the-world/
Lemond is also making some beautiful 27 lb eBikes, but they’re also pricey
https://electrek.co/2020/09/22/greg-lemond-dutch-daily-urban-electric-bicycles/
On the cheaper side a $450 Swagtron EB5 is only 37 lbs
https://swagtron.com/product/recertified-swagtron-swagcycle-eb-5-lightweight-aluminum-folding-e-bike/
The Ride1up Roadster V2 is only 33 lbs for $1045
https://ride1up.com/product/roadster-v2/
You can also find your own light weight bike and get a shop to convert it to electric. If you use a small battery and a small motor this can only add a few lbs of weight. Hope this helps!
Judith Black
2021-05-24 at 12:11 am
This was extremely helpful. thank-you. Yes, there is a company in my neck of the woods, GoeOrbital, (MASS) that creates a wheel you can put on your traditional bike that is electrified.
Profit Greenly (Post author)
2021-05-24 at 4:52 pm
Wow, an eBike conversion company that I hadn’t heard of? Thanks for sharing! Looking at their product it does seem like the easiest to install eBike conversion I’ve ever seen, but I have a few reservations about it.
First, and maybe most importantly for you is the weight. The 700C road bike sized version of their product weighs 21 lbs (https://electricbikeaction.com/amp/product-test-geoorbital-wheel/). Put it on a 30 lb bike and you’re over 50 lbs total with most of the weight in the front making the bike unbalanced. One good thing about their design is that most of their wheel weight is not actually spinning so it’ll have better performance than say the Copenhagen wheel, where all the weight is spinning around (this may be part of the reason why the Copenhagen wheel is no longer sold).
Next, I wonder how true (eg flat) their rim will stay over the years. Regular spoked tires get out of true all the time (you can observe this be spinning an old wheel and seeing how the rim looks wobbly as it passes the brake pad getting closer to it during part of the rotation and further away during the other part). With a spoked wheel a mechanic can return it to true by adjusting the tightness of the spokes (this is almost like tuning a guitar except you want all the spokes to play the same note). If the Geo gets out of true I think it’s just finished, but maybe their orbital engineering never goes out of true? The build videos they posted show the frame to be two thin pieces of folded metal bolted together, so I’m skeptical that it will stay true over the long run.
The final issue I see is the foam filled tires. I’ve long subscribed to the late great Sheldon Brown’s advice on airless tires (https://sheldonbrown.com/tires.html). “They are heavy, slow and give a harsh ride. They are also likely to cause wheel damage, due to their poor cushioning ability. A pneumatic tire uses all of the air in the whole tube as a shock absorber, while foam-type “airless” tires/tubes only use the air in the immediate area of impact. They also corner poorly.”
I can see why Geo had to use airless for their design (the motor would rip off an air nozzle) but they get all these disadvantages because of it. I’d recommend using this tire on a bike with a good front shock to make up for the lack of cushion from the tire, but the internet components of the GeoOrbital itself won’t get any cushioning from the shock, and I wonder how many potholes it will run over before they get broken.
The other problem with a foam filled tire is replacing it’s rubber tread. Sure you don’t have to worry about holes in the tire, but eventually the rubber itself will wear down to nothing and you’ll need a new tread. Unfortunately, since the tread here is glued to the foam and likely the rim as well it’ll mean you need a while new rim filled with foam and rubber. The only place you’ll be able to buy this specialty product will be GeoOrbital itself and who knows if they’ll still be around and making it when you need it. Hopefully they used a very thick rubber in the wheels they produced, but it’ll still need to be replaced eventually.
This is way too much to write about a product that doesn’t even seem to be sold anymore, but it was so unique that the engineer part of my brain really wanted to think about it. The simplest eBike conversion kit that I know of which is actually for sale is the Swytch kit. This whole kit weighs under 7 lbs, so it’ll add far less weight than the geo-orbital and it’s nearly as easy to install. I have heard of people have quality issues with some of the earlier kits they sold, but hopefully after producing many more they’ve worked those out.
For a higher quality motor/battery pairing you could also reach out to Grin Technologies. They don’t make things quite as easy as Swytch but their quality is better and you can end up with an even lighter eBike kit from them if you pick the right stuff. If you’re not an engineer though you might want to find a bike shop near you that will reach out to them for you. Their website does a great job of explaining more about eBike conversions and what to look for in a conversion though (https://ebikes.ca/getting-started/start-here.html).
Judith Black
2021-05-24 at 9:49 pm
Lordie, am I impressed by your knowledge and commitment to this technology. Yup, the weight is what put me off of it, but your explanation now flushes out yet more reasons that it would not have been a god choice. many thanks.
Profit Greenly (Post author)
2021-05-27 at 6:28 pm
Glad it helps. Hopefully you get into a lighter weight eBike either by conversion with a truly light system or by buying one of the ones I messaged about. When you do please leave another comment here, as I’d love to hear about it!
Incredibly janky port of comments from my old WordPress site:
Market News
2020-08-15 at 2:56 am
Hi! Would you mind if I share your blog with my facebook
group? There’s a lot of folks that I think would really appreciate your content.
Please let me know. Thank you
Profit Greenly (Post author)
2020-10-11 at 5:30 am
Sorry for the incredibly slow reply. Yes, please do share this blog. The whole reason I write it is to get this info out there for people!