I can't help but feel like this is thinking way too far ahead. It feels to me that society has to get people into riding bicycles as an option before even thinking about refining the processes around building bicycles. A big factor of lifecycle (heh) assessment is the amount of usage you get out of a given produced object before it becomes necessary to replace. Making the option to ride the bike easier, more accessible, more inviting is how you make bicycles more sustainable.

re: carbon fiber cargo bike emissions
Clearly there needs to be more studies because this feels like very narrow view of cargo bikes especially when the market for consumer cargo bikes is largely occupied by Urban Arrow (aluminum), Riese & Muller (aluminum), Larry vs Harry (Aluminum), and many more that construct cargo bikes out of aluminum or steel. Just looking at some commercial models of cargo bike it seems like for the most part those are made from aluminum as well. I believe that Urban Arrow offers models for businesses.

edit:formatting

i found the AI generated tldr that you originally posted to be a bit confusing, but the article itself was very interesting. Here is my summary of the major points:

1. from a production standpoint, steel bikes have a smaller carbon footprint than aluminum or carbon frame bikes.
2. conventional bikes use fewer consumables over their usable life than electric bikes.
3. among electric bikes, cargo bikes use the most resources to run and maintain.

to simplify this from a long-time bicycle commuters perspective: steel is real 😁

From a purely anecdotal standpoint, I do have a thirty year old steel bike that I still use to cruise around, but I do have a much newer bike for exercise and long distance. I’ve had my steel bike tuned up a couple of times over the years and all the bike shop people say it’ll basically last forever since there’s no plastic on it, which is great.

But I do agree with another poster here in saying we have to get people to know that cycles even exist first. And beyond just regular people city planners and those with the means for change. I’d love to cycle and get groceries where I live, for example, but the infrastructure is poor and dangerous, so I just drive.

I'm not really convinced that lifecycle carbon emissions are the right measurement for most people in the US (and maybe other developed countries, idk). A car is already a given for most people and is a possible option for every trip you take so the best bike is the bike that replaces the most car trips.

A steel frame bike might release less lifetime ghg than an aluminum frame cargo ebike but it doesn't take that long for the ebike to catch up if the limitations of the steel frame means choosing the car more often.

napkin math:

(ebike_mfg_ghg - steel_mfg_ghg)/(car_ghg_per_mi - ebike_ghg_per_mi) https://www.wolframalpha.com/input?i=%28320kg-35kg%29%2F%28400g%2Fmi-%2841kg%2F15000km%29%29

An aluminum ebike only has to replace 720 miles of car trips that the steel frame wouldn't to cancel out it's additional manufacturing emissions. In my experience that really not a crazy number when ebikes:

• expand your radius of effective trips
• reduce the time it takes to make trips
• expands the number of destinations (don't want to be too sweaty or tired)
• can safely carry much more (grocery or shopping trips)

In the long term with changes to infrastructure or density (or if you already live in NYC or similar) then I think lifetime emissions of bikes starts to become a more effective measure to watch.

Feels like it's less cut and dry than this article suggests....

It's weird to me to assume the lifespan of a steel frame vs aluminum when only looking at a perfectly maintained bike. A poorly maintained steel frame rusts out way faster than a poorly maintained aluminum one (does the oxide ever get past the very outer layer?), and I'm not sure anyone bothers recycling the steel bike frame but they do recycle the aluminum one. Also, we're just looking at manufacturing, but wouldn't a lighter aluminum bike require fewer calories to move and therefore cause less carbon emissions from the rider over the lifespan as well? Never mind they mention transportation emissions of old vs new but what about new vs new? Would a local aluminum frame be better than a Chinese steel one, especially if considering the other points I've raised above?

I guess the point I'm trying to make is maybe now isn't the time to really be looking at this. Maybe get more people biking, any bike, and if it becomes a major enough form of transportation then we can worry about transitioning people from better to best.

So you just can a bike after ~12k miles? That's insane.

I guess on average they get damaged from neglect/theft/crashed. But that seems so insane to me.

Interesting read.

I've always wondered about the environmental footprint of regular vs ebikes after switching to the latter a couple of years ago.

I think in my case, one point in favour of the ebike is that it has replaced more car trips? Outside of the winter months, around 80% of my trips around the city are now by ebike compared to perhaps 60% before with the traditional?

Novice bike mechanic here, but a lifelong bike commuter/green collar grunt. I've worked in two bike shops so far, the first being a high-end recreation based shop with an uber-wealthy clientele that bought top-of-the-line carbon machines that they would ride into the fucking ground within a season or two, and the second caters to commuters, lifestylers, and where there is an outdoorsy lean, more x-bike or Crust style stuff. Sure, nothing under capitalism is free from sin, but it still seems to me if you want to go after cycling for being unsustainable, you need to go after the tastes of the wealthy that treat them like toys to shred as opposed to most transport and utility cyclists who, for the most part, are trying to squeeze every mile they can out of their components.

Super interesting!

I believe that until capitalism makes it sustainable, the corporation will not make it sustainable.

15,000 km and only one chain replacement?

Buy a good steel touring or crossfit bike, and it'll outlive you (unless you get hit by a car)

In combination with old bikes, we have e-bike conversion kits. You can get a kit from companies like Cytronex or Bafang with a motor, battery, and battery management system that all attach to the frame and are wired up with a control knob on the handlebars, making a very inexpensive custom ebike. If the system fails for whatever reason and you can't fix it, you can just take everything off and it becomes a normal lightweight bicycle again, but the modularity of it makes it much more fixable and tunable than most bikes that are electric from the factory.

This was a good read!

+1, love steel bikes. My touring bike from 15 years ago is still in good shape, and it's made of steel. Certainly not from the 80s but a good steel bike will last.

One comment on the shared bikes... I live downtown in a major city. Bike theft is pretty common. A private bike probably is better than a shared bike, but I wonder if that still holds true if the private bike has to be replaced far too soon because it got up and walked away on you 🫠