Thursday, November 13, 2014

Feeling Bamboozled?

What's the deal with bamboo bikes?
by Keith Couture


      Bamboo, not just the preferred snack of Panda bears, has long been used to build structures, scaffolding, water transport systems, flooring material, kitchen utensils, boats, not to mention its use as a decoration, or even in cuisine alongside water chestnuts. It didn't take long for someone to conceive of a bicycle made from bamboo, too. The list of boasts about this wonder-material grows:

“Bamboo is lighter than aluminum!” Some say.

“Bamboo has a higher tensile strength than steel!” Claim others.

“It's sustainable to grow! And can also grow up to one meter a day!”

“It can be grown locally!” Another perk.

      But, what really is the deal behind bamboo? Is it all it claims to be? I intend to dispel the myths, dissect the claims, and provide an objective analysis of this auspicious bicycle material.

THE WEIGHT:

      A bicycle's weight is a major concern for a lot of consumers. In fact, for many it is the factor in deciding a bicycle's quality. Could bamboo really be the super-material that gives millions a race-weight bike at a fraction of the cost?
      
     Bamboo is a porous, hollow material, which intrinsically cuts down on weight. The frame builder Calfee Design (http://calfeedesign.com/products/bamboo/) based out of California has bamboo frames that weigh anywhere between 1.8 kg to 2.6 kg (around 4 – 5.7 lbs.). Another frame builder called Cognitive Cycle Bamboo Bikes has frames from 2.4 to 2.6 kg also (about 5.3 – 5.7 pounds). A relatively new bamboo bike builder called Greenstar Bikes (http://greenstarbikes.com/) makes single speed bikes which weighs in at 22 lbs for the complete bicycle.

 The Greenstar Eco-Force 1 weighs around 22 lbs
      
     For comparison, an aluminum racing frame could weigh as little as 2.2 lbs (for an exceptionally light and expensive bike), more realistically around the 3 to 4 lb range, sometimes even including the fork. An aluminum bicycle from a department store, however, could weigh as much as 38 lbs, so material sometimes has nothing to do with it. 
     
     A steel bike can be made to be just as light or heavier, as well. A steel racing bike from the 80's for instance would probably weigh around the 19 lb mark for the complete bike, with a relative frame weight of roughly 4 lbs. Of course, a common chromoly steel bicycle, vintage or new, would likely come in at around 6 lbs for the frame, while the complete build could weigh anywhere between 24 and 30 lbs. A titanium bike or a carbon fiber bike... well, we're not even going to go there. Those materials can be used to build frames that are easily under 2 lbs. Of course there is some variety in the weight of them as well, it depends on the quality of the carbon fiber or titanium, and likewise for any material, be it steel, aluminum, or bamboo.

     The point is, there is a great variety in bicycle weights for any material, and bamboo doesn't have a significant edge over any other. In fact, the standard deviations of each of these materials' weights are likely to be very similar. Furthermore, the components chosen for any given frame and what kind of a build is being done have a great deal of impact on frame weight as well (a single speed will likely be much lighter than a bike with thirty gears and big, knobby tires). So, is bamboo lighter than any other material? It's impossible to measure with all the variables out there. All the major materials are capable of creating bicycles of roughly equivalent weights.

THE STRENGTH:

      Bicycle tubing strength has a lot to do with weight actually. If you're using an intrinsically stronger material you can shave more and more off of the inside of a bicycle frame's tubes, therefore lowering the weight. Some bamboo bike manufacturers boast that their bamboo has a higher tensile strength than steel. I was skeptical, so I really looked into material strengths. The wikipedia page on ultimate tensile strength was instrumental for this analysis. 
     Ultimate tensile strength is the maximum amount of force a material can withstand (in the case of tensile strength, stretching force) before breaking. Turns out there are a lot of different types of steel with a wide variety of ultimate tensile strengths. Bamboo has an ultimate tensile strength of around 350-500 Mpa (Mega Pascals, the unit used to calculate this type of force). It's possible after the bamboo has been treated with an epoxy or resin its tensile strength increases, but considering the ultimate tensile strength of epoxy adhesive is only 30 Mpa, I doubt it's that much stronger. To compare, structural ASTM A36 steel has an ultimate tensile strength of 400-550 Mpa. Ah-ha!

     So, if some really strong bamboo at 500 Mpa went toe-to-toe with some of that steel that managed to top out at 400 Mpa, then yes, bamboo is stronger than steel. However, what are bicycles commonly made out of? These days, chromoly or perhaps during the peak of American and Japanese road bikes in the 80's a different mixture such as manganese-molybdenum. In either case, the UTS of these types of steel are between 700-900 Mpa, well over bamboo. Some steel bicycles are made from steel with strengths up to 2050 Mpa!
6061 Aluminum comes in at 325 Mpa, slightly under bamboo. Obviously aluminum is commonly used in bicycles, so these are strengths which make it perfectly safe to use as a frame material. Bamboo bicycle manufacturers are likely using the few exceptions when their material is stronger than steel to help market their product. Nothing wrong with that! It is vague enough to not be fiction.

THE SUSTAINABILITY:

      One of the reasons bamboo has surged forward as a viable material to build bikes with is because of its suspected sustainability. Nowadays, stamp something with a sticker that says “sustainably harvested,” or “eco-friendly,” or “humanely produced” and it'll sell. Bamboo has those stickers written all over it. It has always been true that the mining industry is one that tends to exploit and abuse the laborers who produce the raw materials for metals (be they steel, aluminum, or otherwise). Some bamboo manufacturers tout the hardiness of bamboo and its ability to be grown in various climates, but the majority of this bamboo is nevertheless harvested from Thailand, Vietnam, and the rest of southeast Asia where it is abundant. There's nothing wrong with that of course. It's likely that the coal that goes into making steel for bikes comes from the same place, and the workers there are likely experiencing much worse conditions. Bamboo definitely seems to have the advantage in regard to the humanitarian aspect of production. What about the environmental impact?


A more traditional looking bamboo bicycle (photo by Flavio Deslandes)
     
     Again, mining coal and other metals is terribly destructive to the planet. Growing bicycles sounds like the kind of idyllic fantasy that you'd come across after landing on a square in Candyland. However, if that bamboo is coming from across the ocean, there's the carbon footprint of that transportation to consider. Not to mention, bamboo does have to undergo a process of treatment which involves using epoxy to join tubes and lugs together (be they aluminum, hemp, steel, carbon fiber, or titanium). The majority of industrial epoxy is derived from petroleum. As a result, the process of making a bamboo bicycle still depends on mining and drilling. There are a growing number of epoxies that are plant based, however. Calfee Designs explains that they use hemp binding along with an eco-resin to construct their bikes, which seems like a step up. However, they also finish the frames off with a satin polyurethane, so there seems to be no escaping the use of petroleum products.

THE VERDICT:

      Bamboo bicycles are clearly the next great thing in bike-building that we should all pay attention to. As with any material, it can be done well, made lightweight, strong, and dependable. It can also be used, just like any other material to build a bike that is a cheap, single speed with knock-off components to keep the price down. It all depends on what goes into the bike. My advice would be the same advice I'd give to any bicycle shopper; do your research, make sure it's comfortable for you, make sure you like how it looks, make sure you can afford it, and you will end up with a fine bicycle. I think even if bamboo doesn't surpass the other materials used in framebuilding, it is at least equivalent in its capabilities. We can safely add it to the pantheon of bicycle framebuilding methods.

     More generally speaking, I think the fact that bamboo bicycles are popular at all is an encouraging trend in and of itself. That we would look to this material for bikes suggests, to me, that we as consumers are becoming more aware of the commodity chain that links us to the people that make our things—bikes or otherwise. The more knowledge we have of how these wonderful machines are produced, the more connected we will be to the people that make them possible, and the more connected we are to those people, the more we have a stake in their well-being, which is extremely important if we want to keep the wheels of the world rolling.

For more info on a few different bamboo bicycle manufacturers check out:



 

Monday, November 3, 2014

The Willingness to Wander

Exploring the connection between human empathy and bicycling

by Keith Couture


     When I first moved to Denver in 2011, I was unemployed, broke, a little despondent, had no friends (in fact, knew almost no one at all), and in my mid-20's, which as many of you may know, makes for a nice combo often called “Quarter-Life Crisis.” Unemployment is never an easy time, whether you're 20, 30, 60, whatever. Not having a solid social network or a reliable group of friends or family for support is similarly hard to deal with. When we face times in our lives like this, it can feel a bit like wandering aimlessly. However, as I discovered, unemployment has its benefits. So does wandering.

     When I was unemployed, one of the things I did—besides cry and surf craigslist for jobs—was ride my bicycle. In fact, I wandered. I was in a brand new city, and no matter what job I was going to pursue, I'd need to get to know its streets. I familiarized myself with the .pdf version of the Denver bike map and struck out on my own. At first I rode up and down the bike paths following them nearly to their ends, only turning back when I saw the horizon getting dark. Then I rode the major bike lanes, the arteries. I got to know the landmarks. I realized how important wandering is in an age of GPS and smart phones. We prevent ourselves from discovering when we take a predetermined route through a city.


                              A well-to-do neighborhood featuring old mansions along Denver's 7th Ave parkway

     I rode slowly past brick coffee shops, yoga studios with their wall-sized windows, brownstone apartment buildings with balconies full of potted tomatoes. I cycled at night and lingered to hear snippets of conversations from porches. I began to get a feel for each neighborhood. Was it a family vibe, where the dominant species was a white 30-something couple with two kids, a Subaru, and a Golden Retriever? Or was it a young neighborhood full of recent transplants, college kids, tattooed baristas, cramped studio apartments, cigarette and marijuana smoke, and divey music venues? Or was it an old neighborhood, full of families that had long said goodbye to children who'd moved out, where neighborliness was part of a noble honor code, the community was tight and held together by a shared history, gossip, and institutions like churches and restaurants; a neighborhood reluctantly waiting for the inevitable gentrification?

     It turns out Denver has all these and more, for better or for worse, and I was able to tap into the hotline for this urban organism's past, present, and future, just by wandering around on my bicycle. The second benefit of my wanderings was that I learned the streets forward and backward. I began to be able to recite the street names from East to West and back between Broadway and Colorado Boulevard. In so doing, I realized an incredibly empowering fact: one need not rely solely on bike lanes.

      As a strong bicycle advocate (and advocate for more advanced bicycle-specific infrastructure), it may seem contradictory of me to downplay the importance of bike lanes. As it turns out, there appears to be a large amount of statistical correlation that suggests bike to motorist accidents increase when bike lanes are newly installed on a street. There is a pretty understandable reason for this. 

     Motorists go about their daily lives mostly unaware of the plight of a bicycler, and when a motorist suddenly finds that the road they take (and maybe have taken for several years) to work has a bike lane on the right hand side of it, their reaction might be nonplussed, but furthermore, no one, not the city, not anybody really, has taken the care to educate these people on how to safely navigate around bicyclers. On the other end, bicyclers who may have been hesitant about riding may be coaxed into a false sense of security because of this bright, new, freshly painted space just for them. You can see how the two don't make for a great outcome. A little education is all that is needed to help these groups of people understand the rights of way and privileges associated with new street infrastructure.

A neighborhood center in Denver's Congress Park, notice the common bike route symbol painted on the road denoting the much maligned "sharrows"
  

     However, this is not to say that bike lanes are bad. Far from it. It's merely that cities frequently use the top down approach to solve infrastructure demands, and many times, they miss the mark ever so slightly. The good news is, a person can bike on any street in the city (unless marked as prohibited such as on highways). Nowhere are you barred from riding. And it turns out that there are a lot of worthy streets to ride on that aren't highlighted in green on a city's bike map. These are the streets that can be discovered through wandering. With enough wandering, one might discover a road that is wide, has infrequent, residential traffic, and very few stop signs to boot. What a gold mine! A street like this is a bike lane that no one knows exists because it's not marked on any map. But now you know about it. Stash it in your mind and bring it out the next time you need to go somewhere that direction. These little discoveries, when accumulated, can help make one a much safer and more confident city bicycler. But the benefits of wandering go beyond even safety and efficiency considerations.

      If I'm to go somewhere new and need to plot a route, Googlemaps might tell me one way, or the city's bike map might suggest one way. However, if I've wandered enough, I might have a counter-suggestion. Sometimes Google is just wrong. Sometimes the city is just wrong—at least regarding what might be a good street to ride on. Or maybe they aren't wrong, but maybe you feel like a different type of scenery than a bike trail next to a creek. To ride through a neighborhood is to take part in that neighborhood's operation, and to strengthen what makes a neighborhood a neighborhood. That is, humans being human in the same place together.

     Cars are intrinsically anti-social. They are incredible pieces of machinery and engineering that unfortunately cut individuals off from their peers and the rest of the world. Sealed inside an airtight glass, fiberglass, and metal container, sounds, smells, and tastes are prevented from reaching the user. Where once a human was perceived as being a human, upon stepping into a car, they take on the persona of a car and lose their neighborliness. Horns have become the voice and sole method of communicating for this human person, who now, suddenly, can say only one thing: a loud, abrasive sound that can convey too many different ideas at once: urgency, emergency, but also anger, exhortation, and unbelievably 'hello!' Of course, the listener needs a great deal of context to understand which is being conveyed.

      Bicycles, on the other hand, leave the human a human. Unless traveling at high speeds (which, be honest, basically makes you into a car), a bicycler has the ability to interact with an environment the same way a pedestrian does. One can wave at friends (or acquaintances, or strangers), say “hello,” “good morning,” “no, you first,” or pause to talk about the weather, or the news, or the plans for the weekend. Sometimes this communication is necessary to safely and comfortably share the road (and the neighborhood) with others, sometimes it is idle chit-chat, but it is also necessary for humans to do because they lead to other important human qualities like smiling, laughing, feeling good, and having meaningful conversations. Being on a bicycle just brings out the human in us all.

In a city where people also walk and bike, humans inside cars are the most cut-off from the rest of their community-members
      

     And now a story. This is a very short story, but it illustrates how bicycling strengthens empathy and neighborliness. A woman was riding her bicycle in Denver last winter. It was a day that had received a significant amount of snow, ten inches or more from early morning to late afternoon. The woman was riding home from work and was approaching a busy intersection where the light was green. Cars gave her a wide birth to pass her as they hurried through the intersection but something caught her eye a half-block down the cross-street. It was a man in a wheelchair who had toppled into a snowdrift. She inferred that this man's wheelchair must have slipped on the ice and fell off of the sidewalk and into the snow. He was clearly trying to right himself but, now out of his chair, he was struggling and flailing. She immediately pulled to the curb, dismounted her bike and walked to the man, whom she asked if he needed assistance. He replied in the affirmative and she pulled his chair onto the sidewalk, pulled him out of the snow, brushed him off, and sat him down again. He expressed his gratitude, she said he was very welcome and asked if he could get to where he was going. He said yes, and they both went on their ways.

     If you or I were in a car about to go through that intersection, would we have seen this fellow toppled in the snow? Maybe. We might have been going too fast to notice him, much less notice that he was in need of a neighbor to wander by. Let's say we did see this person in the snow. Would we have stopped? Hmmmm. In rush-hour traffic on the way home, in the winter, with cars lined up behind us, anxiously waiting to get home—do we put the blinkers on and stop everyone behind us to get out? Maybe. But as we vacillate on the issue, now we're already several blocks away, do we loop around to find a place to park? It seems like too much work to us, and someone else will help that guy anyway. Maybe those of us with the very strongest of moral compasses do stop and invoke the anger of fellow motorists, but the point is, cars set up boundaries that block our natural human empathy which, when unfettered, doesn't hesitate to stop and help another person.

      That woman on her bicycle may not have been wandering aimlessly—she was going home after all—but in a way, riding a bicycle is always wandering. Wandering is open-ended, open to whatever possibility may arise, open to the sights, sounds, and feelings that the city delivers to us. Bicycling, like wandering, leaves us more open to whatever we may discover. We may learn the city's streets. We may learn which ones are good for riding on that aren't actually marked as bike lanes. We may learn the best routes from A to B. But we also may learn much more, about ourselves, our community, and the people that create it.