Russell's Blog

When you're at the gym, do you ever watch all the spinning wheels and slowly reciprocating weights and think about what a waste it is that all of that effort isn't captured and put to work generating electricity? Isn't that a lot of energy?

My usual workout includes a ten mile bike ride, which I usually complete in about 45 minutes with heavy resistance. According to the machine at my gym, I burn about 500 calories, or 2.1 megajoules, in the process. I'm going to assume the machine means kilogram calories, which is what you see on food labels.

Evidently, I'm putting out a bit more than three quarters of a kilowatt. That's a bit more than one horsepower, which is 745.7 watts. This is a bit surprising -- that's not too far shy of what Wikipedia says you'd expect for the first six seconds of a cycle sprint (900 watts). A professional cyclist can hit about two kilowatts during a sprint. So, 775 watts sustained over 45 minutes is not too shabby.

If they had bothered to wire my exercise bike into the grid, LA Fitness would have obtained 581 watt-hours from my efforts. In Pasadena, we pay $0.15 per kilowatt-hour, so I managed to produce a little less than a dime's worth of electricity. If a hundred people did the same workout, which is roughly what I'd expect over the course of a day, we would together generate $8.72. The gym could save that much by switching off the TVs when no one is watching, or turning down the music a little. The electricity you can generate on an exercise bicycle isn't worth the wires that would carry it.

According to the Department of Energy, the average American household uses about 29.2 kilowatt-hours of electricity per day, so you'd have to pedal at the sprinter's pace of 1216 watts, all day, every day, just to keep up with your household use.

My 2.1 megajoules of peadaling is actually a lot of energy. What astonishes me is that even this rather large amount of energy is worth so little.

Update : My friend Chris points out that the bike at the gym is probably reporting some kind of estimate total power, including power dissipated as heat, that it extrapolates from the work you put into the mechanism. He suggests that around 20-25% of the calories you burn are available as work, so that means I am putting somewhere around 155 to 194 watts into the bike. This probably has an error of 50% or worse, since the bike is extrapolating the total power from the mechanical power, and then I'm extrapolating back to the mechanical power from the result. The actual electricity one could generate is more like $0.02 worth.

Yesterday afternoon, my little sister was hit by a car while riding her bicycle across the University of Oklahoma campus. She suffered lacerations and abrasions to her face, lost a couple of teeth, and a number other injuries. She also has a serious concussion. She is now experiencing memory loss, disorientation, extreme nausea, and huge amount of pain.

All of this is, in a sense, good news. She was very, very lucky, given that she was not wearing a helmet. The prognosis is that she will recover completely after some unknown amount of time. My mother flew out to Oklahoma on the first available flight, and she'll be staying with Anna at least throught next week.

She is an exceptionally smart girl, and she knows perfectly well how important helmets are. When we were little, I witnessed her flip her bike and pile-drive her head into the sharp point of the curb in front of our house. She was not hurt, but her helmet nearly split in half. We still have that helmet, even thought it is ruined. The seven inch long, two inch deep gash across the crown makes it perfectly clear that Anna would have died that day, had it not been for a geeky-looking early 1990s vintage Bell helmet. The very first serious email I ever wrote was to thank Bell Sports for saving my little sister.

Now is not the time to wonder why she wasn't wearing her helmet yesterday. Maybe she lost it, or maybe she figured she was only going to ride a short distance, or maybe she didn't expect any cars on campus. We may never find out, given that she doesn't remember the accident. For now, we're focusing on when we can take her out of the hospital, and how long it will take her to recover.

I am writing this here today to ask you, dear reader, to always wear the proper safety equipment. Concussions are not funny. Shit happens. Protect your noodle.

I am going to go ahead and shamelessly plug Bell helmets. Bell has been making helmets since 1954, and they invented the modern bicycle helmet in 1975. Bell saved my little sister once, so they've got my vote for life. Buy a helmet, and make sure it is on your head whenever you so much as handle a bicycle, in case you are overpowered by a sudden uncontrollable urge to peddle around. In fact, buy two, just in case you loose one, or for variety, or for the hell of it.

If you are wondering how to make bicycling safer, you can do two things. Wear a helmet, and bicycle more :

The analysis undertaken in this study suggests that policies which lead to an increase in cycling will not increase the likelihood of cyclist crashes. From the work reported here, it seems the more cyclists there are on the roads the lower the risk that any individual cyclists will be involved in a collision. Road safety professionals concerned about reducing the likelihood of cycle crashes might consider measures that increase cycling.

On my way home from UCLA today, I decided to see how fast I ride my bike from Westwood and to the terminus of the Metro Purple Line on Wilshire and Western. Particularly, I was interested to see if I could get there quicker than the 720 bus. To make it fair, I waited until there was almost no traffic for the bus to get mired in. Rush hour now lasts well into the late evening, so traffic was heavy but not jammed at 9:00 PM.

I waited for a 720 bus to pull into the station, and then took off. It was pretty much a dead heat until the Starbucks at San Vincente, and I got a couple of lucky breaks from the walk signals. I beat the bus to Western by about four minutes, completing the trip in 43 minutes without breaking a sweat. Oh, and it's mostly an uphill ride with lots of pedestrians to which one must yield.

Since I am now commuting to UCLA from Pasadena, I've spent a lot of time wondering how to cut down of the time, expense and misery of commuting. Most of that pondering happened while trapped somewhere on the Ventura freeway, or the perhaps on driving aimlessly around Westwood looking for a parking spot.

To that end, I've started using the Metro as much as possible. The Metro Gold Line is fantastic, and gets me from Lake Street in Pasadena to Union Station downtown in about 20 minutes (less if I catch an express). The Purple Line gets me as far as Koreatown, and this is where things start to suck. From Wilshire and Western, it's about seven miles to UCLA. During business hours, the 720 bus takes about an hour and 45 minutes to traverse this miserable stretch of urban leprosy. The worst part is Beverley Hills, which I would gleefully bulldoze if given the chance.

It's maddening. The first 22 miles of the trip take about 30-45 minutes, depending on intervals between trains. The last six and a half take three times that.

While I was riding a 720 bus packed with more people than I attended high school with, it occurred to me that 6.5 miles in 105 minutes is a little slower than four miles per hour. I could probably beat that walking on my hands.

So, I bought some new tires for my bicycle, and gave it a try. Sure enough, I passed five or six 720 busses as they sat like flatulent beached whales in the morning rush hour traffic. With all the traffic lights, it's a slow ride, but it takes about 50-60 minutes, so I'm averaging between 6.5-7.8 miles per hour. In West Los Angeles, velocities this high are known to cause Cerenkov radiation. I could go a lot faster if drivers would actually look at the road instead of staring blankly into space while driving their Range Rovers in the bike lane, parking in the crosswalk or on driving on the sidewalk to get around busses (yes, really). It would be certain death for a cyclist if all of this mayhem weren't happening at the speed one can push a loaded dumpster up a hill.

There is just one problem, though. When you're not riding it, a bicycle is miserable thing to carry. You may as well be traveling with an Alexander Calder sculpture.

So, I bought a folding bicycle :

This is a Brompton M6R. It folds up really, really tiny, and has little wheels on the bottom to roll it like a suitcase when it's folded up.

Surprisingly, the small wheels don't seem to make much of a difference with stability. The only difference, really, is that it takes a lot less torque to turn the front wheel, even at speed. This makes it feel "twitchy" at first, but the sensation goes away after about twenty seconds of riding. The Bromptons also have really strong breaks. You have to be careful not to pitch yourself over the handlebars.

Compared to my road bike, the Brompton is almost alarmingly responsive. This makes it ideal for crowded situations -- it's easy to avoid unexpected obstacles, squeeze through narrow spaces, and stop suddenly. When it's folded up, it's nice to be able to walk down the train platform without goring people with the pedals or stabbing them with the quick release levers.

The Brompton has two main disadvantages. First, it's a little on the heavy side. I didn't shell out for the titanium version, so it weighs in at 23 pounds. This turns out not to matter very much, except when lugging it up long flights of stairs. The second disadvantage is that I must answer a never-ending stream of questions about it.

I will write a more detailed review of the bicycle itself in a few weeks.