How Green Was My Bicycle?
We bicyclists like to tout our enviro-cred in these days of climate change concern, and there’s no doubt that converting auto trips to bicycle trips does a lot of good. But what about our waste stream? How are we doing when it comes to stuff heading for the landfill?
That’s where we have to start thinking about materials and design, and maybe tell bicycle manufacturers to start thinking about it, too.
Let’s start with the most essential piece of the bicycle: the frame. In the field of waste reduction, the priorities are:
1) Repair – can the frame be repaired if scratched, dented, bent, or broken?
2) Reuse – can the frame tubes be cut apart to be used for something else?
3) Recycle – can the material in the frame be recycled into raw materials for something else (or another frame)?
Cross section of a carbon fiber bicycle frame tube.
Carbon Fiber falls short for all three strategies. Repairing a carbon fiber frame often requires more expertise and time than the frame is actually worth; if it can be repaired at all. Reusing carbon fiber tubes similarly requires the same advanced skills and technology to use them for some other function. Recycling it into its component parts may be feasible in the future, but the environmental and energy ramifications of that are unknown.
Titanium is somewhat better. It’s such a strong metal that it takes a serious crash to damage it. If it is damaged, the frame can be repaired, though it takes a more skilled and knowledgeable craftsman. The same would be said for reuse of the tubing. Like aluminum, titanium can be fully recycled.
Aluminum frames generally cannot be repaired if the metal has been bent. Anyone who has played with an aluminum can knows that just a few bends will make the metal snap. Reuse of the tubing is fairly easy, and we all know aluminum is easily recycled (it actually requires less energy to recycle aluminum than to refine it from ore).
Steel frames are easy to repair with basic equipment and metalworking skills, and equally easy to reuse. And more steel is actually recycled than aluminum.
So next time you’re in the market for a bicycle, ask yourself how important it is to save a few ounces off your bike compared to how much you’ll eventually be sending to the landfill.
For an excellent read on how our waste stream needs to change, pick up Cradle to Cradle, by William McDonough and Michael Braungart. It will change the way you look at the world.
Tags: aluminum, bicycles, business, carbon fiber, environment, frames, recycling, steel, titanium
27. April 2009 at 11:13 pm :
You fail to identify the reason Carbon Fiber frames are the most green house gas friendly of all. It is because carbon fiber is a carbon sink! Once assembled into solid carbon fiber strands, carbon is locked into that state until burned.
Frankly, if you want to reduce your carbon footprint to the smallest it could possibly be, don’t exercise. All that high metabolism stuff releases carbon dioxide (The primary greenhouse gas we are worried about.) at very high rates. Not having a bicycle frame produced at all in the first place will be most environmentally safe choice!
To minimize your negative impact on the planet even more, disconnect your home from the electrical grid and sit as still as possible and try not to breathe.
28. April 2009 at 8:05 am :
The amount of carbon in carbon fiber is inconsequential compared to the amount produced by motor vehicles and power plants. Better that excess CO2 go back into the soil so plants can use it.
Carbon dioxide that humans and animals exhale is part of the natural carbon cycle which is driven by the annual solar input. We exhale it and plants absorb it. It’s worked that way since the first animals came on the scene more than a billion years ago.
The CO2 that we exhale was pulled out of the atmosphere by the plants we grew for food over the past few months, while the CO2 coming out of our tailpipes and smokestacks was absorbed by plants over hundreds of millions of years and stored under ground. We are releasing all that CO2 over a geological blink of an eye; a few centuries.
It’s true that households generate more CO2 than transportation does, but that doesn’t mean we shouldn’t also cut our transportation outputs. Transportation accounts for about a third of greenhouse gas emissions.
28. April 2009 at 8:24 am :
Not sure if the process has changed by building CF frames involves some very nasty chemicals.
I much prefer the ancient steel frames (and the more modern ones) I accumulate bicycles. People give them to me, I find them in the trash, in the ditches along the roads, etc. Ones that can be rehabbed are, ones that cannot are dismantled and sorted for recycling. I even have a deal with the local tire dealer to toss my scrap tires on his pile to be ground up for whatever they grind tires up for these days. Based on total carbon foot print including production steel probably the most friendly.
Aaron
28. April 2009 at 9:57 am :
Good points 2whls3spds. I only addressed the outputs/”end-of-life” side of the problem. The manufacturing process is just as important.
I also should have mentioned bamboo frames. ;^)
I highly recommend the book “Cradle to Cradle” for an eye-opening look at waste and how we might restructure our design, manufacturing and building systems.
28. April 2009 at 10:04 am :
Carbon fiber is one of those “monstrous hybrids” the Cradle to Cradle authors deplore. When you combine organic elements with inorganic elements you often create materials that don’t break down and can cause serious problems to living systems. CF isn’t nearly as bad as say, dioxin, but it’s still a hybrid, and the authors argue that organic nutrients and “technological nutrients” need to be kept separate.
29. April 2009 at 9:31 am :
I hadn’t thought about bamboo, but have seen the end results. They build beautiful bikes, but from what I have heard and seen they are relatively fragile and can be easily destroyed in a crash that a steel frame would probably shrug off. Also IIRC steel is the most recycled material in the world.
Aaron
17. May 2009 at 8:25 pm :
Titanium is not as great as it is marketed to be. The universal acclaim that it has is that (if the bike is properly fitted) it is the most comfortable and enjoyable ride of all the frame materials.
There are scores of reports about titanium seatposts bending and being irreperable and of stems bending. It seems the biggest problems are the welds on titanium frames and if you don’t have a lifetime guarantee from a manufacturer of titanium, you might be in trouble trying to reweld the frame.
17. May 2009 at 11:34 pm :
And many titanium manufacturers have weight limit recommendations (my remembrance is around 230 to 260lbs) for their frames.
28. May 2009 at 10:25 am :
As I’m fond of saying ’steel is real’. Another cycling buddy of mine also liked to say that if they wanted to lighten their bicycle frame by a few pounds they’d just lose some weight themselves. Lots cheaper and probably healthier in the long run.
Now when it comes to drive train components…I can see the desire for lighter materials.
28. May 2009 at 11:02 am :
The most important place to shave weight is of course in the wheels; that’s where the rotating weight is, and the farther from the hub you shed the grams the better — spokes, rims, tubes, tires. But the seconds saved get canceled out pretty quickly if you’re spending too much time at the side of the road repairing broken spokes or flat tires.
John Schubert wrote somewhere that his fastest rides have been on his heaviest bike. (But then John has quite a few extra on him; bike weight is probably completely irrelevant for him.)
28. May 2009 at 5:21 pm :
I agree on the body weight vs. bike weight argument. It is important to advance bike and bike weight technology, but in the end if you’re doing anything (to include training) besides actual training your body weight is of great importance and why should people worry about the weight of good lights versus puny lights when actual body weight is more significant and changeable.
1. June 2009 at 6:18 am :
[...] Bicycling is Better How Green Was My Bicycle Posted by root 15 minutes ago (http://mighkwilson.com) Apr 27 2009 cross section of a carbon fiber bicycle frame tube fail to identify the reason carbon fiber frames are the most green house gas friendly of all leave a comment 2008 bicycling is better is powered by wordpress Discuss | Bury | News | Bicycling is Better How Green Was My Bicycle [...]
1. June 2009 at 7:29 am :
[...] Bicycling is Better How Green Was My Bicycle Posted by root 18 minutes ago (http://mighkwilson.com) Apr 27 2009 cross section of a carbon fiber bicycle frame tube fail to identify the reason carbon fiber frames are the most green house gas friendly of all leave a comment 2008 bicycling is better is powered by wordpress Discuss | Bury | News | Bicycling is Better How Green Was My Bicycle [...]
22. June 2009 at 10:46 pm :
[...] written about how much I love bikes . And walking is even easier on the earth than cycling. No one has to mine molybdenum, titanium, aluminum, or smelt steel for you to hit the pavement. [...]
7. September 2009 at 5:27 am :
Very interesting read. i still love to read bicycle articles even though i cannot ride anymore following my accident. thats why now i spend most my time now promoting bicycle safety. Thanks for the great post.
18. March 2010 at 6:31 am :
very informative! thanks!