Hey folks,

So I’m looking for a new steed to blast through the winter commuting period, hopefully to last a good few years. I know the pros/cons of steel vs carbon from a performance perspective, but I’m not particularly bothered about a heavier/flexier bike costing me 30 sec on a commute.

What I want to know is, what’s more environmentally/ethically responsible?

I’m interested as one of the main arguments against carbon always seems to be that it’s difficult to recycle (but not impossible) and uses pretty nasty resins, but how much worse is it compare to steel?

Does anyone have a rough idea of typical energy expenditure to manufacture a carbon frame vs steel frame?

I’d guess there’s not a huge difference in terms of how long you’d expect each to last as they both fatigue pretty well.

Cheers,
Dave

The world steel organisation (so possible a bit biased) says:

“On average, 1.8 tonnes of CO2 are emitted for every tonne of steel produced”

Whether that includes extra working, who knows. I’d imagine tubing to be higher because it involves a fair bit of working/processing. Economy of scale also helps mitigate the vast energy needed to smelt etc.

Carbon has a long supply chain and big carbon footprint, and produces harmful substances as by-products.

Both will suffer from emissions from huge shipping distances.

How likely is a steel frame to be made using recycled material?

It would be interesting if someone could cobble together a comparison table for full life cycle carbon footprint, environmental impact, etc, etc for either option…

Ultimately you will find every product you buy has a significant environmental impact, how you use it and how quickly you replace/discard it will dictate how significant that really is more than it’s initial method of manufacture IMO…

Buy a second hand frame 🙂

There’s an interview with Max Commencal where he says they don’t do carbon anymore because it’s ethically unsound. I seem to remember he had quite a list of reasons why. It’s on PB, I think.

at the end of it’s life are you going to send your carbon bike to be be recycled or are you going to throw it in the skip.

That is assuming you have not sold it to someone else who will then probably skip it at the end of it’s life.

As someone who works in composites I shouldnt say this but metal. I’d actually not be surprised if an aluminium bike is better than a steel one due to lower processing temps and easier machining.

But on the other hand a bike you keep for longer will have a lower impact…

Carbon fibre won’t be great for the envionment, or probably last as long as steel.

But if you really value the thics that much, buy something UK made in reynolds steel, it’ll be the only combination not shipped halfway round the world! But spending the extra £900 or so it would cost would buy a lot of trees.

Bamboo of course

I’ve been thinking of building a wooden fat bike. You can get bamboo kits if you want to go that route too.

In fact cant you just walk!

Buy a second hand frame

This, get a steel one and it will last a lifetime if looked after/repaired when needed,so that surely has to be the best option if you’re bothered about that sort of stuff.

Bamboo of course

Grown locally or shipped to the UK? and bonded with?…. Epoxy resins perhaps?

Bamboo ain’t that environmentally friendly, I still fancy making one some day though…

http://bamboobicycleclub.org/

Where do Reynolds get their steel? And where does the blast furnace get their ore? And its fuel?

Interesting points. I’d like to think that I’d recycle both of them. But it seems that recycled steel is much more useful than recycled carbon. But I guess it’s pretty energy intensive to turn back to a useable product.

@warpcow, I saw that interview, that’s kind of what got me interested. It’s difficult to know how much of that was a genuine reason for not going carbon, and how much of it is an ‘excuse’ for not having the capital to invest in a carbon frame.

It’d be awesome to get some a lifecycle analysis between steel/ally/titanium/carbon, covering manufacturing, expected life and end of life disposal.

Any lifecycle specialists out there?

But if you really value the thics that much, buy something UK made in reynolds steel, it’ll be the only combination not shipped halfway round the world!

Except of course none of the steel is actually sourced from the UK and only some of the tubes are made here.

So it’s entirely possible that the steel is sourced from the US, made into tubes in the UK, is shipped to Taiwan to be made into a bike and then brought back over to the UK where you buy it.

It’s “extended use” really isn’t it, better than re-manufacturing/recycling there’s always repair and re-use those are the most environmentally friendly options, but just not as new/shiny…

It’s worth noting that damaged Carbon frames (very badly damaged ones too) can be repaired of course, arguably more easily than a steel frame…

As has been pointed out, the real answer is getting a second hand frame regardless of the material given the environmental impact of shipping and manufacturing in the first place.

Otherwise, IMO you’re just trying to greenwash your choice which is fine but don’t try to pretend otherwise.

I’m happy to buy second hand (and probably will, last 2 bikes have been), but there’s still the question; is a second hand steel frame significantly better than second hand carbon frame?

Not trying to justify buying carbon over steel, just wanted to try and get a quantifiable answer if possible?

It’s like trying to get an answer on Prius’ green credentials – It all depends what you want to consider, which figures you taken and which side you want the answer to fall out in favour of.. 🙂

cookeaa – Member

How likely is a steel frame to be made using recycled material?

extremely.

scrap steel is an excellent feed-stock for a steel furnace – even for the exotic/niche vacuum re-melted stuff.

My hunch is that steel frame with reasonable tube thickness as it will last so long. Steel should also never end up in land fill

Carbon might be in the game but Except for some FS stuff and the 456 most carbon is designed to be really light. Which can’t help durability

This looks helpful

http://www.welshcomposites.co.uk/downloads/environmental%20webinar.pdf

If its correct it looks like its steel

CF only gets a look in if its lowering energy use e.g. lighter cars

but there’s still the question; is a second hand steel frame significantly better than second hand carbon frame?

No, in both cases the things been manufactured, shipped and used already, the lion’s share of it’s polluting is now done, by purchasing it 2nd hand and wringing as much use out of it as you can you help “amortize” that environmental debt across more years of use.

Nobody really seems to know which has the higher upfront environmental impact TBH…

And this

could be a bit biased but it doesn’t sound marginally better for steel

http://www.smartplanet.com/blog/intelligent-energy/steel-industry-carbon-fiber-an-environmental-culprit/

Any lifecycle specialists out there?

I’ve had to do a few. Off the top of my head steel stuff tends to be about 6-10kg CO2 per kg of product, plastics usualy 3-5kg/kg (refineries are much more heat integrated than blast furnaces, then processing plastics is at much lower temperatures than metals).

So carbon may actualy be less CO2 (but can’t be recycled as easily).

But as both have to be shipped from tiawan, and both are bulky/low density products I’d guess theres a higher embeded carbon cost in the transport alone than those balpark figures.

Case made. There’s no absolute figure out there that everyone will agree on. Buy either, use for a long time instead of driving and you’ll be way ahead on footprint. Do second hand and you’re even better. Better yet, save a frame from the tip! 🙂

@cookeaa, there’s still the end-of-life disposal and expected lifetime to take into account. It’ll be interesting to see in 10 years how many carbon 456’s there are kicking around compared to how many steel inbreds/456s.

Thanks for the links @ampthill, seems like steels the out and out winner for human powered bikes then! That second article is interesting too, definitely makes sense to tax the entire lifecycle rather than just usage emissions. So by introducing legislation to reduce carbon emissions, we’ve somehow found a way to increase them, wahey!

Life cycle analysis would be the whole life and not just your ownership so the recycling aspect really comes into play as does the components you choose to put on the bike. Also if you want some real context look at your ecological footprint and see if some small gains in CO2 are completely outweighed by other lifestyle choices either in or outside your control. I talk to supposedly ethical people all the time who don’t seem to consider how it all links together. After 20 years in this field I’m as depressed as that polar bear that’s being bandied around at the moment.

If you’re after a ‘steed’ then I’d recommend a horse.

Go for a Woodelo bike frame made from Irish Ash, I think. Not cheap though.

You just need to buy a frame that’s never going to make landfill. A ‘forever bike’. I suggest something really expensive and titanium – And justify it to yourself on environmental grounds.

Steal is real.

Carbon is…dunno teally. Plastic ? 🙂

Yeah, your frame should be like the best type of music – metal.

[video]https://www.youtube.com/watch?v=yfB7vF7nCdA[/video]

Also to be considered are the working conditions of the 3rd world factory the frame is made in. Carbon dust very carcinogenic?

as alexei sayle pointed out in the new statesmen, the best way to save the planet is to kill yourself 😯 http://www.newstatesman.com/global-issues/2013/07/alexei-sayle-what-makes-us-human-we-need-realise-best-things-life-are-not-thin so on that cheery thought
carbon fibre is not currently recycled allot because the resin used contaminates the recycled product (like mixed steel in a skip), carbon itself is the basis of life on earth so can be used many times if you can extract it out, it’s exactly the same when recycling steel. carbon fibre has grown into the material of choice for it’s strength to weight ratio – and when you use it applications like these http://www.toray.com/ir/pdf/lib/lib_a136.pdf
then you need less energy to run the car or plane overall.
studies suggest that carbon fibre is slightly better for that reason, although I haven’t found a conclusive answer.

adsh – Member
Also to be considered are the working conditions of the 3rd world factory the frame is made in. Carbon dust very carcinogenic?

Probably similar to the 3rd world iron/steel works.

Further to muddy9mtb:

[video]http://www.youtube.com/watch?v=bXEddCLW3SM?[/video]

Just wondering why aluminium hasn’t come into the discussion? It probably has a similar impact to steel, but so many bikes are alu.

faustus – Member
Just wondering why aluminium hasn’t come into the discussion? It probably has a similar impact to steel, but so many bikes are alu.

We all know aluminium is harsher than steel or carbon

Googling “alu steel environmental impact” brings up a lot of stuff from the auto industry that seems to suggest that steel would be preferable for bikes. Gist of it would be that alu production has more environmental impact than steel, but makes up for it with improved fuel-consumption for cars. Now we just need to know the environmental impact of cyclists’ cake consumption.

I didn’t know alu was worse than steel or carbon, but thought it worth looking at as so many bikes are made of it…