“What can go wrong, will go wrong, usually at the most inopportune moment.” Like when it’s dark and raining, for instance. Murphy was a wild-eyed optimist.Posted by Hurricane Hattie to CycleDog at 4:32 PM
Hurricane Hattie has left a new comment on your post "Road1...continued":
From your Sep. 10, 2006 blog:
"Finally, I heard from several students who've read CycleDog. In fact, one said she was persuaded to try bicycle commuting by some of these posts. I have mixed feelings about influencing people. "I suspect you mean me. I've been meaning to respond ever since I read this. I read your blog regularly and compose lots of rants, rebuttals and raves as I go down the road. They just never seem to make it to (virtual) paper.
Rants, raves, and rebuttals always seem to come easily when I'm in the saddle, too. The hard part is remembering the best parts to write down later. This is especially true when I've hit on something that strikes me as hilarious, yet when I arrive at home, I can't remember what it was! Maybe that's another manifestation of middle age. You may rest easy on my account. For one thing I was close to commuting on my bicycle before I ran across your blog and would have done it anyway. You can be sure I did it more safely for having read your blog. Another reason you needn't be concerned is that unless it's extremely cold if I'm not riding my bicycle I'm riding my motorcycle - a Kawasaki ZZR 600. I've been riding a motorcycle as my primary transportation since I was about 15 and I'm several times that now.
One point I've tried to make recently is that a good cyclist, or a good motorcyclist, for that matter, needs to know everything that a motorist would know: rules of the road and best, safe practices, among them. But we need an additional set of skills in order to ride safely in motor traffic. That's the whole purpose of motorcycle skills clinics, and it's the stated purpose of BikeEd.
Back in the days when dinosaurs roamed the Earth - the 1970's - I rode a Yamaha RD250. It's very possible that I now weigh more than that motorcycle! I'd love to have another one, but then I'd probably avoid riding my bicycle. And I need the exercise far more than I need a motor bike.
After reading your blog I realized I've ridden a bicycle most of my life and knew nothing about it. I learned enough from your blog to keep me reasonably safe when I started commuting. However, the Road1 class was a godsend! It was such a wonderful class and I learned so much! It was just what I needed. I have since run into a couple of people (literally in one case) on bicycles that would benefit from a Road1 class and volunteered to pay for it if they would go. I hope they take me up on it.I have found a solution for dealing with people who honk at me. I wave and pretend they know me and were just saying "Hi." I used to let my temper get the best of me and make rude jesters but realized one day I really might know them. Although recently when a lady made a left turn in front of me I chased her down in the Wal-Mart parking lot and had a little talk with her. She seemed to really think bicycles were always supposed to yield to cars. But we got that straightened out.
I'm finally writing because I need help. I will be riding in the dark soon, one of my shifts starts earlier, and I need lights. I've looked around online and there is a vast array of cycle lights available, some of which could be very painful to the wallet. I managed to assemble my winter riding clothes very inexpensively thanks to your blog on winter clothing. Could you write something on lighting? I would appreciate it tremendously.
There's nothing I love more than a plaintive cry for help! But before you read through my take on bicycle lighting systems, just be aware that I've included several links to more authoritative sources, Sheldon Brown, Steven Scharff, and Peter White, at the end of this post. They cover this subject in more detail, and they're better informed than I am.
First, a caveat. I've tried several different light systems, including small, handle-bar mounted units powered by AA or C batteries, cheap bottle-shaped generators, and one expensive (though now obsolete) dual beam unit. All have advantages and drawbacks. The dual beam headlight was the only one I'd trust if I were bombing down a steep hill at 30 or 40 miles an hour. It threw enought light that motorists sometimes thought there was a slow-moving motorcycle on the road!
The battery powered units don't throw as much light, but they're adequate for modestly paced night rides. Currently, I'm commuting behind a Cateye HL-EL300 and a Cateye HL-EL140. The HL-EL300 provides most of the light, while the HL-EL140 operates as a back-up. I'm a firm believer in system redundancy! I don't claim these are the best lights on the market. They were available at Tom's when I needed them. But they do have some nice touches for commuter lights. Both are easily removed at the end of a ride, and the HL-EL140 doubles as a helmet light. It has a versatile mounting bracket and it has a flashing mode.
Generator lights are divided into two groups: very good, very expensive ones, and cheap junk. Shimano and SON make high-end generator hubs that I find very appealing. But just like the HID units, cost puts me off. Cheap bottle generators are little more than kid's toys. Avoid them. The expensive units include some sort of voltage regulator. The cheap ones do not. I had a cheap unit on a commuter bike once upon a time. I was bombing down a hill, going faster and faster as the light got brighter and brighter, until - poof! - it was gone and I was going very fast in the dark.
Before discussing various lighting components, let's cover some basic physics. No math! I promise - sorta.
When we look at lighting systems, there's a bewildering variety of power measurements: watts, candlepower, lumens, candelas, and possibly more. In most cases, comparisons are difficult because while watts indicate input power, the rest are indications of output power. The input power to a device is easy to calculate. Power is equal to current in amps multiplied by voltage. It certainly seems simple. The problem comes in when we consider the efficiencies of different light producing devices. Incandescent lamps are very inefficient, converting input energy into both light and heat. Heat (or infrared radiation, if you prefer) is wasted energy since we can't see it. Light emitting diodes are far more efficient at converting input energy to light, and in fact, heat is a big disadvantage with these solid state devices. If they get hot, they die.
Obviously, an efficient device can either run longer on a given power pack, or it can provide more light over the same amount of time as a less efficient one. For cyclists, this means we can carry smaller,lighter battery packs.
Most bicycle headlights are either halogen lamps or light emitting diodes (LEDs). Halogens may have an edge when it comes to sheer power. They put out more light than a similar LED unit, but they do so at the expense of shorter run times. Remember, halogen lights waste a lot of energy as heat. Halogen lamps are usually replaceable, where LEDs are not. (I'm ignoring HID light units, partly because I know very little about them, and partly because they're stop-your-heart expensive, which is why I know little about them.)
Reflector design can have a great impact on relative brightness - what's apparent to the human eye. The now-defunct Bicycle Guide magazine did a piece on this many years ago. They set up various light systems in a parking garage and photographed the light patterns each unit produced. Some were very tightly focused beams best used for road cycling, while others were broad, diffuse patterns that mountain bikers would like. Producing a well-lit broad light requires a lot of power, but the narrow beams do not. It's all in the reflector assembly. (This is very apparent when looking at beam patterns for auxiliary lights for automobiles, driving lights, fog lights, and some other supplemental lights, for example.) To make it even more confusing, some have broad patterns in close to the headlight, but also produce a narrow beam that illuminates farther out. So a comparison of relative power outputs is meaningless without a comparison of the beam coverage.
Some LED units offer both flashing and steady modes, but the flashing modes may not meet legal requirements everywhere. In Oklahoma, for instance, flashing lights are limited to use on emergency and maintenance vehicles. Still, many cyclists use tail lights in flashing mode and I've never heard of anyone being stopped for it. The basic bicycle lighting requirement here is that you have a white front light, a red rear light, and a red rear reflector. I would strongly advise that you have an amber rear reflector too, one that meets DOT specifications, because it's visible over a greater distance than any red reflector. (Come to think of it, that just reminded me that my amber reflector went missing. Gotta fix that!)
If you go with rechargeable batteries, the choices are usually lead-acid, nicad, or nickel-metal hydride (NIMH). The differences come down to weight vs power output. Lead-acid batteries are relatively cheap, but they're very heavy. Nicads and NIMH batteries can produce equivalent power while weighing considerably less, but they're expensive. Again, it's a trade-off. (I once sat through an engineer's lecture regarding the internal differences between lead-acid and nicad batteries, including the chemical processes. Honestly, while he went on for about 3 hours, I stayed awake for only the first 20 minutes. I could never drone on and on like that, boring an entire roomful of people. And don't listen to my daughter. She lies.)
The most critical aspect of rechargeable batteries is the charger. As a charge builds up, the battery develops internal heat. Without going into a long discussion, heat ruins batteries, so the less heat build up, the better. But preventing that requires longer charging times. The manufacturer's solution is the 'smart charger'. It puts a high current into the battery for a short period of time, then switches to a lower current as the battery nears capacity, and some units even monitor the battery temperature while charging.
For anyone interested in home-brew lighting equipment, the rule-of-thumb is to limit input current to not more than 10% of the amp-hour capacity of the battery. So a 2000 mAH battery would be charged to capacity in 10hours at 200 milliamps, or 20 hours at 100 milliamps, etc. Low charging currents limit the heat, and by keeping them very low, you prolong battery life.
Steven Scharff's pages:http://www.nordicgroup.us/bikecoff/
Coffee - how could I resist?http://www.nordicgroup.us/hosted/
Index to all pageshttp://nordicgroup.us/s78/
Very useful links
Labels: bicycle, bicycle light, Cateye