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Comment by midoridensha | Hacker News Reader

There's a few reasons some people prefer steel. 1) You can weld it pretty easily, if your frame cracks. I guess this is nice if you're bikepacking through Nepal or something, but I don't really see the practicality for normal people. 2) It's cheap (well, not any more). 3) It's more flexible than aluminum, so some people prefer the way it rides.

These days, I'd say #3 is the only really valid reason for most people. Steel bikes are generally heavier than aluminum however, but it is possible to get them close if you use a high-grade cromoly steel, but then that removes most of the cost advantage.

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#1 matters if you want to own and ride a bike for a few decades, which used to be a relatively common thing.

I've seen no evidence that aluminum bikes don't last a few decades. Frame failure is not a common failure mode in bicycles.

I've had two frames fail with fatigue cracks at ~ 10k miles or less. One steel (at the chainstay bridge weld) and one aluminum (at the seat tube/bottom bracket weld).

Not only can you weld steel, it also is more forgiving in the failure mode. Steel bends and the damage to the frame is better visible (and could be corrected, if you prefer so) while aluminum frames can develop hidden defects and catastrophically fail.

#4: steel bikes have a lower carbon footprint than aluminium bikes.

In like........any measurable way? I'm not being funny, I'm honestly curious.

The lowtech magazine published this number¹:

> Scientists have calculated the lifetime carbon emissions of a steel bike at 35 kg CO2, compared to 212 kg CO2 for an aluminum bicycle.

[1] https://www.lowtechmagazine.com/2023/02/can-we-make-bicycles...

That's super interesting - it's a lot more than I would have thought it is. Metal is metal, right? Didn't think the difference would be so large.

I'm not sure on all the particulars, but metals are not the same: some require more energy to work with or to refine than others.

Steel (IIRC) needs a lot more energy to melt than aluminum, however I think aluminum requires more energy to extract from ore. Also, IIRC, aluminum needs more energy to weld just because it conducts electricity so much better, even though it has a lower melting point.

Contrary to iron, silver or gold, aluminium has to be chemically extracted. The mineral you extract aluminium from is bauxite. This chemical process was mastered so recently that the Washington Monument is tipped with it just to show off. Even then the tip is so small that you can barely see it with your own eyes, but you can see it in Spiderman :)

https://thescienceof.org/spider-man-washington-monument/ https://www.youtube.com/watch?v=lPVzP2Jfdgs

Yeah, I think Napolean used to show off his wealth by using aluminum silverware at his fancy dinner parties.

Frames made of wood do exist, their footprint is probably even lower.

They tend to use a lot of toxic resins though. Same for bamboo made bikes.

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