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Bamboo Bike A Reality
markjugg writes "The American Bamboo Society has a page describing a working bamboo bike. This is a strong step towards making bicycling more sustainable, expecially in contrast to aluminum, one of the most resource demanding materials that exist."
I am a bike-geek as well as a Lunix-Geek:
The bike is a single-speed. That means it does not need gears, breaks or even a ratcheted freewheel (on the back wheel)... the pedals are connected directly to the rear wheel by the chain. If you want to slow down you use your legs.
Single-speeds are favourites of city-couriers, where there is a great advantage to have a light-simple bike. There is less to break (XTR gear systems are known to wear out after a few weeks of couriering).
As for Aluminum - dont get me started on that nasty harsh material. There has been a disturbing trend for wannabee bikers to adopt the freakiest lightest materials at the expense of all other properties.
For me, steel still has the edge over all these fancy materials. A steel frame will last for years of hard riding, and still feel as plush as the day it was first ridden.
He's prolly referring to raw aluminum. Extracting it consumes way too much electricity. Of course, recycling aluminum takes very little.
"I might have made a tactical error in not going to a physician for 20 years." -- Warren Zevon
My Structural engineer friend told me that Bamboo is better than steel if used properly and since it just grows like grass it's basically free.
A bamboo bycicle would be neat but, as a natural product you aren't going to get uniform material to work with so every bike would probably be completeley different to an other. You wouldn't be able to mass produce these things.
Doing a little googling I found this report about using bamboo instead of steel in reinforced concrete.
any way that's my bit out of the way.
A
Particularly in the orient, but in other places as well when times were either hard or when metals were subject to civilian restriction, such as during WWII. Wooden bikes have also been used at times.
They don't work very well. Bamboo is strong, but it's also very flexible. This is also the reason that molded plastic bikes ( as opposed to fiber reineforced plastic bikes) have never worked. If a plastic is ridid enough to make a good bike frame it's also to brittle.
Aluminum is energy intensive to originally produce, but the cheapest and easiest metal to recycle. It also doesn't rust away to unusable oxide, making aluminum the most green of the metals in the long run.
In any case you'll still find most bikes made of steel, because iron is common, easy to smelt, easy to turn into high quality steel, easy to recycle, cheap, and, while not necessarily the highest performing material for a bike frame in any particular measurment, it is, nonetheless, in the top 90 percentile in every attribute needed to make a good bike frame.
What's more, you need very little steel to make a bike whose usable lifespan may be measured in decades. I have two ridable children's trikes over 100 years old.
There's simply nothing about bamboo bikes that make them more sustainable than a steel bike, and they're nowhere near as good.
KFG
I think the bamboo bike is really cool from a cost perspective, but it's not really any more renewable than an aluminum one, nor having a net advantageous resource budget despite the obvious, intuitive expectation that it would.
The matter system on this planet is closed loop.
While this is not entirely true, some 40,000 tons of space borne dust land on our planet and we may someday mine extra-planetary bodies, for arguments sake all the aluminum we're going to use is here now. If we continue to use it all the bauxite will be gone some day, and from then on, all aluminum will be recycled.
However, long before that day all aluminum will be recycled because it costs 20X as much to make aluminum from Bauxite as it does to remelt it from scrap. The aluminum industry uses all the scrap aluminum it can get because the final product is just as valuable as aluminum from ore, but the profit is very different.
So aluminium the matter is a renewable resource, just like the carbon in bamboo, except to reuse aluminum it need merely be remelted via heat (typically electrical power, though a solar furnace could be used), and the carbon in bamboo must be oxidized and reduced (typically by rotting or burning and then photosynthesis).
Most domestic aluminum production happens in the pacific northwest where the power is provided by dams, a renewable resource, but certainly much of it is provided by oxidizing hydrocarbons to produce CO2 and H2O, both end state products that require substantial energy to reduce to reduce back to something chemically useful. This return cycle of oxidized hydrocarbon energy production is managed by the biomass of the world, and is driven by solar power via photosynthesis at 0.2% net efficiency, just as bamboo production is.
The energy system on this planet is constant rate
All energy on this planet comes from the sun. The sun has provided a net energy surplus for a few million years, most of it stored in reduced hydrocarbons (about half in oil and half in methane hydrates, and a comparatively inconsequential amount in leftover fissile heavy atoms). The world's total carbon reserves (1.6E13 bbls oil equivalent) contain enough energy to provide current consumption (globally 1.2E14 Kwh/year) rates for 221 years. If the rest of the world catches up with US consumption rates all the reduced carbon in the world will only last 38 years.
So, sooner or later (within 200 years, longer if there's a big global war or other population reducing event, much shorter if growth continues) all our energy will come from solar power directly as we will have consumed the planets "life savings" of net reduced carbon.
Photosynthesis is 0.2% efficient. Photovoltaics are currently about 10% efficient (20X more) in commercial applications (7.5% efficient over the life of the device) and efficiencies of over 30% are achievable.
To meet next year's global energy demands (1.2E14 Kwh, not including firewood) would take only 6.5E7 M2 of commercially available solar panels for $1.3E10 at current retail. The world will spend $4.4E11 on oil alone next year. If we spent 5% extra on oil (global tax) we could fully fund global solar power within a year. Interestingly, to meet the US's entire current energy demands with solar electric, we would need to cover about half of our roads, at no net change in albumen.
Within 200 years, and probably within 50, all the energy used in the production of aluminum will be direct solar.
Bamboo vs. Aluminum just isn't that obvious
Bamboo is a very impressive material, basically a single orientation composite, which can be easily reinforced against torsion and it's comparatively low modulus can be compensated for with larger diameter tubes in a bicycle, but it is not obvious that it's a more efficient use of land to grow bamboo than to use solar power to recycle aluminum into new bicycles.
But we have a long way to go on energy use and recycling, and so bamboo is an o