Archive for November, 2009

After researching and writing the article on alternative materials, I knew I needed to write an article dedicated to bamboo.  According to the Book of Bamboo by David Farelly people have been making bicycles from bamboo since at least the late 19th century. Its a natural material for a bicycles since it grows in strong tubes that are relatively straight. It also happens to be lightweight, very strong, and in abundance in many parts of the world. Bamboo takes as little as 3 years to mature for use, and can grow almost anywhere. To make bicycle tubing from raw bamboo you don’t need to do that much. Harvest, cure, and cut to size. All other bicycle tubing material requires some kind of production that involves many more steps than what bamboo requires. The point I’m trying to make is that bamboo could be the most sustainable material to make a bicycle from. There is no mining involved to obtain the raw material, almost no energy is used to produce the tubing, and when grown responsibly bamboo is a source that just keeps on giving!

I’d like to show you some examples of bamboo bicycles that are currently being made. I’ll start off with Craig Calfee. Take a look what Calfee has done with Bamboo. The properties of bamboo make it a competitive material for making high end racing bikes of this very style.

I took it upon myself to do a few simple calculations comparing steel to bamboo. For comparison I used a 4130 steel cross section having an outer diameter of 28.6mm and a wall thickness of 0.6mm. This is a common size for seat tubes and down tubes on road bikes. Using the yield strength of 4130 steel I determined the maximum load this section could bear before yielding in compression or tension. I then took that load and determined what area of bamboo would be strong enough to support it without breaking. 4130 steel has a Yield strength of 63,100 psi, and bamboo has a Ultimate strength of 8,700psi (Janssenn, 1991). The reason I used the yield strength of steel and the ultimate strength of bamboo is because failure is considered when steel yields and when bamboo cracks.

I then took the resulting section of bamboo and tested it against the steel section in bending. I imparted a maximum moment on a simple beam end to obtain the maximum deflection. The maximum moment was determined by the sections geometry, and strength. The maximum deflection was determined from the sections geometry, strength and modulus of elasticity (E). The E of 4130 steel is 30×10^6psi and the E of bamboo is 2.7×10^6psi (Janssenn, 1991).

From that simple structural analysis I determined that a bamboo tube with a length of 24″ having a diameter of 1.5″ (38.1mm) and a wall thickness of 0.15″ (3.8mm) will have the same strength in compression and tension as a 4130 steel tube of the same length and diameter of 28.6mm (1.12″) and wall thickness of o.6mm (0.02″). These two tubes also deflect the same amount when a maximum moment is put on one of the tube ends (see the bending diagram below).

Bending Diagram

Bending Diagram: Simple beam, End Moment

Now, having two tubes of similar axial strength and rigidness, I calculated the weight of each tube. For the density of 4130 steel I used 0.283 lb/cubic inch and for bamboo I used 0.014 lb/cubic inch (Jansenn, 1991). The weight of the steel tube comes out to be 0.56 punds while the weight of the bamboo comes out to be 0.21 pounds. This of course does not include the internodes of the bamboo. The steel tube is over twice the weight! No wonder folks build bikes from this stuff! The next set of calculations I’ll do is to compare how these tubes act in torsion as well as repetitive stress. If you want copies of the calculations I’ve done, just ask. I didn’t want to post them so as not to bore people. Now, how to connect these tubes to get a lightweight, stiff bicycle?

Calfee uses carbon fiber with resin to secure the joints of the bamboo. For the high end bamboo bicycle makers out there, this seems to be the method of choice. Here is a photo from Brano Meres Engineering:

Brano Meres Engineering

There are also folks out there constructing these bikes using natural fiber and resin at the joints such as Bamboo Bike Studio and Evolve Bicycles:

Bamboo Bicycle Studio

The other type of joint I’ve seen out there is by the newest builders to the bamboo scene, Panda Bicycles. The are making bamboo bikes from external steel lugs. Similar to how older steel road bikes (and many new ones too!) are made.

Panda Bicycles

The tubing on the Panda bike is smaller than on the others, and clearly the joints are different. They hope to be a more economical bike than those other fancy ones. Right off the bat, Panda’s tubing is looking slightly thin to me, and I’d worry about stress spots forming along the edges of those lugs, but I think they are on to something. I think there on to making bamboo bikes for everyday people here in America and not just the high end market. Lets get a sustainable material in the mass market for new frames! Bamboo Bike Studio in New York is also on to this idea, except they offer a class for one weekend where you walk away with bicycle in hand for about $1000. Evolve Bicycles also has the right idea offering their pre-built bikes for $800.

Since bamboo grows everywhere, bamboo bikes can be made anywhere. There are organizations like Bamboo Bike Project who have dedicated their cause to showing certain groups in Africa how to make bicycles from their native grass, and now there are groups sprouting up in America showing Americans how they too can make bicycles from bamboo. What an exiting time!

I’ve started my own project revolving around bamboo. Looking at the joining methods currently used, I’m not completely satisfied. I don’t believe the joint needs to be as bulky as the fiber wrapped joints, and I think having steel external lugs on bamboo tubes may present problems in the long run. I’ll try building a frame with another method I’ve devised to see if it is viable. You’ll be able to keep track of the project here at The Sustainable Cyclist.

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I don’t subscribe to Bicycling magazine, so I don’t get to read the editors introductions all too often. It just so happens my grandmother-in-law likes to send me things about bicycles. In the mail today, I got the September issue of Bicycling magazine courtesy of her. Who knows how she got it, but that’s not the point. Loren Mooney, the editor-in-chief of this publication, wrote a letter to the readers entitled “It’s Easy Being Green”. She starts the piece by announcing this issue of Bicycling is the Green issue, even though there is nothing to indicate this on the cover and none of the content is different than usual. She then goes on to say that Bicycling magazine is “Green” every month. Why? well because cycling is green! Thus, her logic is that her magazine is “green” as well. This, ladies and gentlemen is GREENWASHING!!!!

I couldn’t find an online version of this prime example of greenwashing, so I scanned the magazine page.

It's easy being green

It's Easy Being Green by Loren Mooney

She goes on to say that cyclists are more environmentally friendly people. She backs this up with personal anecdotes. So, because Loren grows her own lettuce and buys organic milk, ALL cyclists are more environmentally friendly than the rest of the population. right! Also according to Loren a characteristic of being environmentally friendly is noticing those ugly bottles, cans, and trash on the side of the road as well as breathing, and appreciating fresh air. Gee wiz! according to Loren, all you have to do to be green is ride your bike, enjoy fresh air, and dislike garbage on the side of the road! This may even give you more ideas, like buying local and organic food products. So, after you go on your evening training ride dressed in spandex riding your titanium steed that was just upgraded to Dura-Ace last season, you can sit down to an organic dinner and a copy of Bicycling magazine and know that you’re helping the earth. And just in case your feeling a little guilty about buying a magazine printed on paper every month, Loren assures us that bicycling recently switched to paper stock that use’s “slightly less fiber” and ink that is “vegetable based“. Oh boy, so instead of switching to FSC certified and recycled sources, you decided to uses “slightly less fiber“. Apparently the reduction in the fiber is so small, she had to use the word slightly. I’m not impressed Bicycling magazine, and I hope your readers are smart enough to recognize this poor attempt at greenwashing.

What is greenwashing? Simply put greenwashing is a company’s attempt to jump on the eco-friendly/green/sustainable band wagon without actually doing anything except change their marketing. You can read more on wiki. They want people to think “wow, that Bicycling magazine sure is doing their part to save our fragile planet” when actually, they are doing absolutely nothing. In fact, I could argue that they are doing more to hurt the earth then if Loren never wrote that pathetic piece of marketing crap. How? by the very act of greenwashing! There are legitimate companies out there trying to do their part to be more sustainable and eco-friendly, but when a company partakes in greenwashing, the consumer has a tougher time determining what is a legit green product, and what is not. This pulls attention away from the companies that are actually trying to help our Earth. Companies who greenwash essentially muck things up and it pisses me off!

Bicycling magazine really could do a green issue. They could interview community bicycle shops that work tirelessly to get used bicycles back on the road. They could promote steel bicycles over carbon fiber. They could eliminate their advertisements and articles promoting titanium. They could eliminate car advertisements in the magazine. They could feature articles on Bamboo bicycles and the people who build them. They could print their magazine on 100% post-consumer recycled paper. They could showcase the clothing companies using wool instead of synthetics. They could focus on bicycle commuting over bicycle racing. These things are just a minimal start. I can think of hundreds of things they could do for a green issue!

I’m angry! I’m angry because Loren and Bicycling wrote this piece as a strategic marking move and nothing more. It distorts the view on companies that really do care about the earth and strive to make sure it’s habitable for generations to come. This is just another example of the bicycle industry being way behind.  Just because you ride a bike does not make you “green”. It takes a lot of hard work to live your life in a sustainable way. It is not “easy“. Riding a bike instead of a car for transportation is one way of being more sustainable, but if you drive your car to work everyday and only ride your bike in the evenings and weekends, you’ve done more harm to the earth than if you never bought a bike in the first place. Why? Because in order for you to be a “green” bicycle owner, you have to use it instead of your car, otherwise, your doing more harm than good by purchasing a non-sustainable bike product. Bicycling magazine owes it’s entire community an apology for trying to mislead them.

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If you travel the online world of cycling its hard not to come across Competitive Cyclist. They are the keepers of all things “high end”. This includes repair work as well. As I’ve eluded to before, a common perception among aficionados of the high end, is that if it’s a couple seasons old, its time for some new stuff. I’m not sure where they get this idea. Hmmmm, lets see, it couldn’t be that the major companies in the component industry come out with new products every single year and need their marketing departments to get consumers to buy the new product and ditch their perfectly working older model for the sake of performance? could it? In order to stay competitive with each other, these companies believe they need a new product every year, and they need to convince us that the stuff we already have needs to be upgraded. That way, we buy it, they make a profit, and their sale numbers are better than the competitions. When Campagnolo came out with 11 speed Super Record, I was reminded of that MadTV skit about razors. Now, of course, Shimano has electronic shifting. What’s next? I’m all for innovation, but not for making stuff just for the sake of making stuff.

Here is a bit of evidence that marketing goes a long way to make sure planned obsolescence stays part of their game. Listen to what Andy says about his old group! Its quite clear from this video that the folks over at CC could care less about the sustainability of their products. All they seem to care about is selling top shelf bikes and bits in as large a quantity as possible. You still riding that Ultegra groupo from 2004? Whats wrong with you?

In case you couldn’t hear him, this is what he said: “…and since my Dura-Ace 78oo was a few years old, it was the perfect time for me to shop for new components…”

So, if your components are a few years old, you better hop right on over to CC and pick up yourself some brand new components that will be ready for ditching in just a few years time! What a deal!

I’m ashamed this sort of marketing goes on in the cycling industry. Why not sell a product that is ethically sourced, will last forever, is completely serviceable, performs well, and is as innovative as I need it to be. I would pay a little more for that!!!! To boost sales, the companies could invest in lobbying in order to pass laws that make our streets more cycling friendly. They could also invest in advocacy programs and community bike shops that strive to get folks riding bikes. This would mean more people riding bikes, thus more customers for them to sell their goods too. As of now, they focus their attention on the top shelf riders, and count on all the other riders to keep upgrading, because maybe, just maybe, that 11th cog will get you that Cat 1 status you’ve been dreaming about.

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Another team doing it right! Here is quote from head coach Hugh Moran:

“So my thinking went something like this: if the bicycle is the ultimate ecological vehicle, then couldn’t the cycling team be the perfect promotional vehicle for the college’s “green” initiatives and its partners in the effort?”
Good idea Hugh! Things like this make us at The Sustainable Cyclist a bit more hopeful. You can read about the team at usacycling.org.

Go Mars Hill!

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