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. ]]> http://mighkwilson.com/2009/04/how-green-was-my-bicycle/feed/ 17