Anyone know actual typical manufacturing carbon dioxide emitted for Ally , steel, carbon bikes?

Internet has pointed me at these but they blend it in with lifecycle cost not just manufacturing:

https://www.bikeradar.com/features/long-reads/cycling-environmental-impact/

Cites 250kg for a specialized allez frame which seems huge.

https://www.ecf.com/groups/cycle-more-often-2-cool-down-planet-quantifying-co2-savings-cycling

Seems to indicate 960kg for a fully built up Dutch commuter bike.

Lots of businesses now going carbon neutral and reporting on their footprint. Wonder what data manufacturers have on how much is produced by each bike. Don’t know if singletrack themselves have ever done an article on this or not, strikes me as would be a good one.

This is as much as I could see on treks website – use of green energy but no mention of the carbon story

https://www.trekbikes.com/us/en_US/company/sustainability/

Likewise some good supply chain initiatives from the big S but not much if anything on carbon :

https://www.specialized.com/gb/en/sustainability

With only some my own ‘common sense’ applied 😉 my guess would be that carbon is probably lower on the scale as it doesn’t need such huge quantities of energy to extract and create the raw materials.

Would be interested in new aluminium vs recycled as there would be pretty minimal energy (comparatively) to form a frame from recovered allie. That’s probably the least impactful option environmentally.

That’s all just guesswork though.

carbon fibre relies on the polymers from refining oil, the high temp and pressure autoclaves for curing use massive ammounts of energy the manufacturing itself generates a lot of non recycleable waste and the final product is a nightmare and landfil.

Would be interested in new aluminium vs recycled as there would be pretty minimal energy (comparatively) to form a frame from recovered allie. That’s probably the least impactful option environmentally.

When I worked in the aluminium industry in the 90’s the ‘back of the fag packet’ ratio was that a drinks can made from recycled aluminium took 5% of the energy that one made from ‘fresh’ aluminium did. Although this does hide the sheer carbon ‘cost’ in the first place.

Which is why in any manufacturing process using aluminium the waste is fully recovered & recycled.