tonka.toy

How Eco friendly is an aluminium bike?

I ride about 16 miles a day that would otherwise be done by London Underground.

Economically I can pay of my new bike in about 6 months (not counting the endless upgrades) but how many times do a I need to ride to work in order to outway the environmental cost of production of the bike in the first place?

pj7

Ask this same question in the "Living Car Free" forum and I'll bet you'll get more information on this than you could have ever imagined.

Cyrus

Might as well kill yourself. It's the ultimate eco friendly way.

But seriously; 1...just 1 time.

braingel

Buy a used bike.

ax0n

Just ride and enjoy it. As long as you keep those pedals moving, it will eventually more than balance out. Life is way too short to worry about such trivial matters.

lyeinyoureye

The differences between an Al and steel bike are likely negligible. As was mentioned before, buy used. A better question would be, which uses more energy, biking, or public transit... Which depends on how fast you ride, what you eat, and how efficient public transit is.

ax0n

See, now you did it.

cerewa

Making a bike isn't the most eco-friendly thing, but it's worth it. Public transit is by no means 100% sustainable, and doesn't give you the health benefits of cycling. I suspect there are a lot of indirect environmental costs that come from the extra health care you'll need if you're inactive. And non-bicycle exercise equipment also uses resources.

lyeinyoureye

Like locusts... Locusts!

Bizikleto

The question is not whether alu or steel bikes are or not eco friendly, but whether there is any other means of transportation that is more eco friendly than an alu or steel bike. I'm not an expert on bicycle manufacturing and production, but I think that all in all, alu and steel bike production could be very similar environmentallywise.

tonka.toy

just musing about how long to ride it before I can buy another without feeling guily!

bbunk

How long do you have to ride the subway to offset the environmental impact of making the subway cars? How many bikes can be made from one subway car?

newbojeff

To some degree, isn't the train going to run anyway?

fordfasterr

if they installed pedals on the train, then the passengers would have to pedal it through the tunnels... etc... that would help out quite a bit !

mcoons

Theoretically, Steel can be repaired much more easily than Aluminium, so as far as useful life, that is something to take into consideration. Also, you are more likely to find a used frame of steel than one of aluminum.

I agree with a lot of what has been said. In some instances, it is similar to buying a car, as you can get more bike by buying used, and replacing a few pieces - wheels, chain, grip tape. Sometimes it might be more expensive, but sometimes it just takes a bit of patience.

I bought a Surly Cross Check used from a guy on Craig's list, added fenders, my own pedals, a brooks seat, and a custom rack, and it cost about the same as a new Cross Check, but I have an eclectic bike that I customized to my needs.

bigpedaler

the nice part about the env. cost of a bike is that is almost all paid up the moment you get on it. with something motorized, the cost is just BEGINNING....

CommuterRun

Maybe only once. Depends on how fast you get hooked on it.

lyeinyoureye

Quite a few bikes! The problem is that per passenger, the energy use of high speed rail is so much better than cycling (humans aren't very efficient, and their food definitely isn't) that any gain in fewer capital costs is likely wiped out by increased operation costs. For example, the ICE (InterCityExpress) supposedly uses 29wh/seat*km at 200kph, and the Transrapid 22wh/seat*km at the same speed. The average cyclist uses about half that energy at an eighth of that speed. But... unlike the train, which uses fossil fuels or electricity generated from fossil fuels, wind, nuclear, hydro, etc... directly, the cyclists' fuel, food, requires more energy to get to the cyclist than the cyclist can get from it.

On the high side, meat for instance, every unit of energy on the cyclists plate may require 50 units of fossil fuel energy. On the low side would be something like potatoes, bananas, or cheap bread, each unit of energy may require something like 3 units of fossil fuel energy. And on average it's supposedly around 10 units of fossil fuel energy for every unit of food energy. Assuming the absolute minimum, the cyclist uses about the same amount of energy the train does, but travels 175kph slower. On average, a cyclist probably travels 175kph slower and uses ~three times more fossil fuel energy doing so.

An electric bicycle is equivalent to a high speed rail in terms of consumption, but has the same disadvantage in terms of speed. Otoh, it can be easily powered by a single solar panel, so it may be the way to go in terms of energy efficiency.

Now, assuming a passenger train ca weighs 50,000kg, and is made of nothing but Aluminum, it would require ~10,000,000Mj to make from virgin materials. Since the average cyclist uses 2Mj/mile at ~25kph more than the train at ~200kph, the train would need to go 5 million km compared to the cyclist for the energy cost of the two to be equal. Of course, this is making the assumption that the train costs as much as possible, and that it requires no repairs, and actually weighs 50,000kg, all of which are probably wrong. I'm guessing the train would pay off it's initial investment compared to cycling at ~2 million km, because the production cost is probably a little more than half of a pure Al object, but repairs tack on energy.

That being said, there's no need for high speed rail to take you 5 miles down the road. Or for individuals to swear off motorized transportation and bike 50-200 miles. Unless they want to for the hell of it.

Yesh, but, might as well take advantage if you want to. Lack of use will only lead to a push to abandon mass transit, so that people have to bike or drive, with no middle ground like the US (for the most part).

Going back to the OP, worrying about Al or steel is splitting hairs. You'll save more by switching to LED lighting, insulating, and getting a lay down fridge than the difference between Al and steel bikes. Bike for your health, not for environmental concerns... Either one (bike or mass transit) is o.k. from that POV imo.

Bizikleto

Well, trains are there for moving people from one place to another. And the passengers they all eat! Then your statement would be like «humans take ~three times more fossil fuel energy by eating than rail trains by moving». The increase of food intake when the cyclist cycles compared to when they don't is negligible. So, taking aside the human-transportation factor (transporting eating humans makes the train's energy effectiveness plummet, and no eating human to be transported means no train), and taking into account that trains or planes have to be full of passengers ALL the time they move to be that effective, and considering that if we got to gather some 200 people to cycle together on a "cyclotrain", the cycling effectiveness would dramatically increase, it seems that transportation alone is more effective on the bike.

Because of enthropy, balance of energy and thermodynamical interaction, everything on Earth takes its toll of environmental burden: stones, flowers, our very breathing (let alone eating and moving). The question is that, come to the point we are at present, we should make what we can to make that burden the lightest possible.

CdCf

One can always argue that cycling requires food energy and that that food energy has a fossil energy cost that is much greater. But very few people eat so little and ride so much that they have to increase their food intake to be able to ride. Indeed, it wouldn't surprise me if most active cyclists eat less than many couch potatoes...

crtreedude 

You are probably right - the coach potatoes out there are really packing on the pounds so they are probably in the same consumsion levels as we are. The only difference is that when we die, we won't need an XXXX size casket, except perhaps if we are buried with our bikes.

lyeinyoureye

Well... You can start tossing on other social confounds if you like, but then you start having too many variables with unknown relationships and everything is futzed up. For instance, by bicycling a person will increase their lifespan by say ~10-20 years, and their energy consumption will increase, to the point where any gain by cycling instead of driving is wiped out. Otoh, we can say that cyclists are more likely to use less energy intensive devices.. But how much more likely? Personally, I've seen vegans eat some expensive isht, which is definitely not fossil fuel friendly food, so to speak. There are studies that investigate how many calories of fossil fuel energy go into food, but none that investigate whether cyclists actually use less energy, etc. The more variables, the more relationships, that probably haven't been investigated. That being said, eating is separate from cycling. I can eat precisely what I need, or I can overeat, but that doesn't change the fact that cycling has a significant fossil fuel penalty. Exercise is great, and if a person wants to exercise by biking ~10 miles a day instead of doing something else, sure, why not? But claiming that cycling is a viable form of transportation because it doesn't use fossil fuels, even if you do, is just silly. But, this is what a lot of car free advocates do... Nuts.

They don't have to completely full ALL the time to be effective. If a cyclist is using three times more fossil fuel energy by way of food, a train at a third capacity consistently is just as efficient, and still goes ~175kph faster. That being said, there are cycling arrangements that can be effective high speed transport, I've bounced them around the car free forums, but as you can see some car free members care more about image than efficiency...
Quite a few car free advocate/s don't care much for reasonable alternatives. They just want to spout off about how they're environmental saviors because they're car free.... etc. Even if their food source is based on significant fossil fuel inputs. This is also why I advocate electric bikes with wind/solar charging... After the devices pay back their fossil fuel energy inputs, they're essentially providing fossil fuel free energy, and on the velomobile scale, all one needs is a single panel.

Do you mean enthalpy or entropy? I think we have consistent cyclical ecological systems that change slowly over time for the most part. As of today we're taking huge chunks out of these loops, so they're going to start changing rapidly if they haven't already, which isn't exactly in our (as a species) best interests.

Yep yep. But very few people cycle that much in the first place. Don't you think that's a bit disingenuous? As I've said before, might as well exercise and do something constructive. But many car free advocates insist on nothing but bikes, which is silly, since we only need ~10 miles per day for exercise, and after that we're using a bike for transportation, which does have the huge fossil fuel penalty. Personally, when I was knocking down ~15-20 miles per day, I had to increase my caloric intake and eat healthier. YMMV, but it's not like everyone overeats so much that they can replace their car with a bicycle. There's some more in my first reply to Bizikleto.

Bizikleto

Lyeinyoureye, I think I put too many words to explain a simple idea. Sorry about that. There it goes reworded:

According to your thesis, it is the resource-devouring food chain the cyclist lives on (and maybe clothing chain etc.) that makes the cyclist so poorly energy-efficient. Since train passengers live also on that same food chain, clothing chain, etc., it follows that the train's energy efficiency decreases in direct proportion to the number of passengers it carries. (Hence my insistence on that trains must carry people for their existence to be justified, and following your reasoning, that very need makes them so energy-ineffective.)

It follows that there are many factors linked to the way of life of the particular cyclist (mostly western or from an economically developed country) that can make their whole life (not just cycling) environmentally abusive (for example, as you mentioned, there can be one vegan that inflicts more damage to the environment by their wrong choice of products, than some other meat-eater). And this highly energy-dependent and fossil-fuel burning way of life will be so for cyclists and for train passensers alike! So let's not let ourselves be confused here.

Therefore, cycling itself is definitely an environmentally sound (if not the most so) alternative to short and medium-distance transportation.

Cheers.

lyeinyoureye

Not quite... Here's how the processes are different.
Train- Fossil fuels -> energy/materials -> train
Person-Fossil fuels -> energy/materials -> farm -> human/bike

The fossil fuels to energy/materials has an efficiency of around 40% on average. Then it's used directly in the train to move people. Or... It's used by a farm to make food, at ~10% efficiency (10:1 calorie of fossil fuel:calorie of food ratio), which is then used by a human to move themselves. The energy efficiency of the train has nothing to do with the people, unless they're actually powering the train by pedaling or something similar. Bicycles otoh, are powered by people, and the energy source of people, food, has a high fossil fuel overhead. There's also the matter of the thermodynamic efficiency of the train's engine, and a person's metabolism, but that's would be twice as much at most, so it's not pertinent to the point, which is that food production requires large fossil fuel inputs for most, and this makes human powered transportation less efficient. Unless you grow all your own food with no fossil fuels, then... you're fine.

The thing is, I need a certain amount of food to live, plus the amount I need for exercise, to extend my lifespan and increase my standard of living (according to some). I might as well get my exercise and do something productive at the same time. Instead of using a reciprocating saw to cut wood, I can chop it myself, and get exercise while saving some energy. Or I can wash my clothes by hand, Or... whatever. Up to the point where that exercise is beneficial for my health. I'm saying, everyone (in an o.k. situation) should exercise no matter what, so they might as well do something productive and exercise. But after they've gotten the exercise they need, any physical activity that requires more than the usual daily caloric intake is wasteful. So biking past ~10 miles per day, or cutting more than X amout of wood, or whatever I need takes on the food:fossil fuel penalty once I get past the amount of exercise I need and stop combining two daily activities into one. If you need to go down to the store 5 miles away, then biking is relatively environmentally sound. If you want to go to another town 20 miles away, it's not compared to other alternatives. And it's definitely not compared to something like a velomobile with electric assist/solar panel.

That being said. Quibbling about this stuff isn't exactly picking low hanging fruit when it comes down to environmental issues, and it's irritating when every yokel that rides a bike claims they're an environmental savior. If you're concerned about yourself, ride a bike because it's great exercise. If you're concerned about your wallet, ride a bike because it's cheaper, sometimes. And if you're concerned about the environment, switch to LED lighting, low power computers/displays, insulation that's as good as it gets, line dry your clothing, etc... And, ride a bike instead of driving short distances. If you're really concerned about your impact, go build an electric velomobile. If these little things can go ~80mph on ~400W of human power on flat ground, with the help of a small electric motor, a larger, more comfortable version could do just as well. Besides, getting speeding tickets in 55mph+ zones on a bike is just to cool...

froze

You want something you can do that is eco-friendly...WALK BAREFOOT!

I don't care how you guys spin your crap, but anything just by the nature of the manufacturing process alone IS NOT eco-friendly! The only mode of transportation other then walking and by animals that comes close is probably a bicycle made of bamboo with beech wood rims...but you would still have the manufacturing process involved with all the other parts on the bike. The high speed train thing is just insane; the amount of pollution from manufacturing the train and rails and all the infrastructure is mind boggling.

And the reason you have to walk bare foot for? Because unless you buy all natural footwear you would probably walk around in a pair of high tech tennis shoes that again have the manufacturing process as well as the problem of once they wore out they don't rot away in land fills very quickly.