A blog friend over at PedalWORKS posted a graphic that shows traveling by bike to be the most efficient mode of transportation – of course, this is until you have to deliver a half-dozen bundles (10 per bundle) of 12′ framing studs to your boys in the field, but I digress. Taking that graph as truth, something struck my fancy: I’d be willing to bet that, even though I’m incredibly good-looking and intelligent, I’m not too efficient on a bike because I ride too fast. This little quandary led to a few vastly more interesting points… Remember these when your local politician starts talking about taxing bikes.
Interestingly, estimates on a cyclists actual “miles per gallon” equivalent vary. If you go by HowStuffWorks‘ numbers, (15 mph, 175 pound individual, 30 pound bike) you get 912 mpg. Another site I checked out did the math and came up with just shy of 1,450 mpg (15 mph, 210 pound individual, no bike weight given).
Where this gets interesting is that I only travel at 15 mph if I have a 20 mph headwind. On an easy, windless day I’m upwards of 18-18.5 mph while I’m over 20 when I’m actually working. The problem becomes wind resistance. The faster you go, the harder you have to work because it takes more energy to push through the wind. Going back to that second individual who came up with 1,450 mpg, he figured an average of 90 watts… I’m upwards of 220 watts (20 mph, 170 pounds, 17 pound bike, no wind, no grade 735 k/cal per hour). The calorie content equivalent of a gallon of gas 31,000 k/cal… 31,000 / 735** x 20 = 843 mpg. By that same calculation, by the way, I’d be closer to 1,313 mpg at 15 mph (354** k/cal per hour). You could also do this equation another way, by figuring out the calories per mile, then dividing 31,000 by that number and you get the same thing. In any event, I think 1,450 is too high and 912 is too low but let’s face it, when you’re six times more efficient than an electric car*** – at the low end, does it really matter?
Finally, because politicians suck and are, in large part, dumber than the public*, let’s look at the really cool thing about cycling: Cyclists feed trees when they ride their bikes. The EPA (bureaucrats, a group of people whose sole purpose is to make your life suck more) notwithstanding, let me be very clear: cyclists, much to the chagrin of politicians, do not pollute the atmosphere by riding a bike to get from point A to point B. Let’s look at that graph from that post I mentioned earlier:
So we can fairly say that cycling is just shy of three times more efficient than walking in terms of caloric requirement but it gets better. Walking is also vastly slower so more respiration is required to get from, say your door step to the corner store two miles down the road. In other words, walkers “pollute” (read that “breathe”) more than cyclists. Think about it for just a minute: A cyclist, at 15 mph, can make that trip in eight minutes. A walker, at a 16 minute mile pace, would take four times longer to cover that distance. I take six breaths per minute resting. Riding at 15 mph and walking 16 minutes per mile would be just about the same effort (not much) so figure that would go up to 10 per minute… It would take me 80 breaths to ride to the market but 320 if I walked it. Do the math folks, four times the CO2 to walk rather than ride.
In other words, my dear politicians, the only other way to create less CO2 is to sit on one’s couch. The real question you’ll have to answer is why do you promote obesity when it’s an epidemic? Why do you promote death and disease, worse yet, why do you promote diabetes for your constituents?
I know, I’m a samurai. It’s my nature.
* I wrote that politicians are stupid. Most are not, at all. Most are exceptionally intelligent but they come up with incredibly stupid reasons to justify what they want to do. Take raising your taxes, or taxing bikes: Politicians have claimed that cyclists should be taxed because their increased respiration is “pollution” according to the EPA. It’s plant food, dude, not pollution. Also, going by the increased respiration argument, I’ve shown reasonably that walkers should be taxed at a rate four times that of cyclists. In other words, the position is ignorant from the start. Politicians clearly spend too much time with lobbyists and spinsters. That’s all I’m saying.
** I used the Bike Calculator to come up with my calories per hour. Those numbers were always quite close to (a little under) my stats tracking software. That software takes everything into account. Weight, wind, pace, wheel size, tire thickness, grade…even where on the bars I place my hands (bar top, hoods or drops) – I went with hoods even though I spend most of my time in the drops nowadays.
*** Based on the BMW i3, the most fuel efficient production vehicle ever, of all vehicles tested.
I had the strangest thing happen on my ride Tuesday night… I’m riding along and all of a sudden I hear this odd noise at the front of the bike when I’m out of the saddle, climbing a hill. It sounded like something was rubbing, or maybe like a bearing was going bad. In addition, I noticed a slight warble in the wheel (and by slight, I mean maybe a 2 or 3 mm). I checked the brake clearance by lifting the front end and spinning the wheel while I was out on the road and even though there was a warble, the wheel wasn’t rubbing on the brake pads and there was no noise with the pressure taken off of the front end – I had to look elsewhere.
I rode on and other than the noise when I was out of the saddle, the bike performed fine. When I got home the investigation began. First, I knew I had to true the wheel so I started there. I turned the bike upside down and cranked down the brakes using the barrel adjuster to determine the spot to start. Much to my surprise, one spoke had worked itself loose – and by loose, I mean loose. There was a fair amount of play in that spoke. Tightening the spoke fixed everything.
In the last three years or so, I’ve put more than 12,000 miles on my bikes and have never had a spoke loosen up on me like that so it was a quite a surprise to simply be able to put a 3/4’s of a turn on a spoke and eliminate two problems. Point is, bike maintenance is pretty simple and logical – as long as you understand the logic… and that’s kind of the trick, isn’t it?
UPDATE: Kecia, a good blog friend, added in the comments section that she had a friend crash because of a loose spoke. She brings up an interesting point that I really didn’t get into in my post but definitely weighed on my decision to keep riding rather than investigate immediately: I was on my 5200 which rolls on Rolf Vector Comp wheels. They are a deep-V, thick walled aluminum rim and are known for being among the most structurally sound aluminum wheels ever put on a bicycle. I reasonably believed that I’d be okay if I kept riding. Now, had I had this problem on my Venge which rolls on Vuelta Corsa SLR rims – a full pound lighter than the Rolf’s, I’d have stopped and looked at the spokes on the side of the road.