From: MARTYGOODMAN@delphi.com (Marty Goodman MD KC6YKC)
Sender: owner-bikecurrent@cyclery.com
To: bikecurrent@cycling.org,

This last week I and Zach Kaplan did night riding with a prototype of a new technology in bicycle lights: the CatEye "Stadium" metal halide lamp. This is my final report and summary of that experience. Zach Kaplan rode with me on some of these tests, and he will comment too. I am a casual recreational road rider, who rides occasional century rides. Zach is a dedicated cyclist who commutes exclusively by bicycle, and has set course records in rides and time trials in numerous places. Zach often must ride at night, and often in places where there's almost no street lighting, for he lives in a relatively rural part of West Marin, in the San Francisco Bay area. Both I and Zach enjoy riding at night, and are especially intrigued by lighting systems for bicycles. Both I and Zach have in the past ridden with many different popular lighting systems on their bicycles at various times, and written pieces about bicycle lighting on numerous occasions. I am also an electronics tinkerer who has extensively modified a number of his own lighting systems.

The prototype CatEye Stadium lamp we tested consisted of a lighting head similar in size to a Night Rider Cyclops, which could be clipped in and out from a mounting on the handlebars. From the head came a 3 foot cord permanantly attached to a water bottle. Inside that waterbottle were both the electronics for driving the lamp and the 12 volt NiCd battery for powering it.

The lighting head was, we were told, the same as that which will be in the production version. The cord from that head, and the packaging of the electronics for the lamp in with the same waterbottle that held the battery pack were all "prototype", and there will be a different arrangement on the commercial production version. I have been told that there will be an "electronics package" permanantly attached to the lamp via a short cord, and that a plain battery (in a water bottle) will attach via another cord to that electronics package.

The lamp and the electronics will be permanantly joined because of the need for voltages of from 100 to 6000 running between them.

The overall size and weight of this lighting system is comparable to the existing NiteRider and Night Sun and Turbo Cat and Vista Light VL5xx systems.

I normally ride with a 6 watt / 10 watt CatEye dual beam NC200 system AND a NiteRider 15 watt cyclops light. I added the CatEye Stadium lamp to this system, to allow quick comparison while riding between parts or all of my system and the CatEye Stadium lamp.

The Stadium put out visibly much more light than all 31 watts of my existing three halogen-bulb system. Equally if not more significantly, the sides of the road were illuminated quite brightly by the CatEye Stadium, where even with all three of my lamps lit, illumination to the sides of the road was minimal. CatEye states that it designed the reflector for the Stadium for a narrow 10 degree beam. But what I experienced in using the Stadium was a bright area in a ten degree beam ahead of the bike, PLUS a 30 degree or more wide area illuminated less brightly, but still far more brightly than with any of my other lamps. QUALITATIVELY far more brightly.

It's hard to express how different the experience of riding with this CatEye Stadium is from that of riding at night with any other bicycle lamp. With all my other lamps, I feel like I'm riding into a narrow tunnel of safe visibility. With the CatEye Stadium, night riding becomes more like riding during the day, with objects on the side of the road clearly visible both close to the bike and quite a ways ahead. On a stretch of road unlit by street lamps, as we cruised at 25 mph, a cat darted out from the side of the road, in front of our bikes. We could clearly see the cat begin to move when it was as much as ten feet to the side of the paved road, and about 50 feet ahead of us. This enabled us to have plenty of time to make allowances for it. With conventional lighting systems, this part of the road would have been too dark to see the cat.

Zach was familiar in general with metal halide lamp techology, which has been around since 1962. Prior to our ride, he was hesitant about making time to see the Stadium (which I had for just that one last night before having to return the prototype to CatEye). He felt that, at $400, it was so expensive that he was not likely to be going out and buying one, so he did not feel that motivated to bother to check this prototype out. However, he did join me for the ride. Within ten minutes of seeing the CatEye Stadium he went from not being interested in buying one to becoming certain that he would buy one as soon as it was available. THAT's how dramatically different this lamp is. In Zach's case, his motivation was that he commutes exclusively by bicycle, and often at night and on unlit roads, and the massively greater and wider light beam from the Stadium would both increase his overall safety during commutes AND allow him very safely ride much faster than he could with his current lighting system (a NiteRider Commuter).

The CatEye Stadium has the distictive bluish white color of metal halide bulbs. This is a psychologically a "cold" color, compared to the much more psychologically "warm" color of halogen lamps, with their yellowish-white output. However, the slight bias to the blue of the halide arc lamp seems to better pick up flaws in dark pavement.

We compared the CatEye Stadium light to a single one of my automobile's halogen headlamps. The Stadium was visibly brighter, and illuminated a wider area, than my headlamp on low beam. My headlamp on high beam was brighter than the Stadium. This is what I would expect, given that the Stadium is rated to put out light equivalent to an 80 watt halogen lamp, and with my car's headlamps the normal beam is about 50 watts, and the bright beam is about 100 watts.

There is no question in my mind that metal halide bicycle lights will eventually completley replace all current high end bicycle night lights. This is NOT an incremental improvement in bicycle lighting. It's a dramatic leap. For now, CatEye is the only company to offer this technology.

Who Will Buy this Light?:

$400 is a lot to spend on a lighting system. It's half the cost of a decent road or mountain bike! Not every night rider will be rushing out to buy one, I know. Competitive and agressive night mountain bike riders will probably constitute the largest group of the first batch of riders to buy CatEye Stadium lamps. For these folks, the massive extra overall light in general, and the stunning extreme angle side illumination in particular, will translate to considerably increased possible speed on twisty single track runs. Very serious road bike commuters, like Zach, will also be among those buying CatEye Stadium lamps, provided their commute will fit within the 1 1/2 hour run time of the Stadium lamp, or that they are comfortable carrying a second charged up water bottle battery for longer run times.

Criticisms: (1) Run Time.
CatEye chose to use a 21 watt bulb with a 2.8 or so amp hour NiCd battery pack. The result is a system with a run time of about 1 1/2 hours. This is somewhat limited. To some extent this problem will be addressed in the production version by the ablity to carry a second battery bottle, to double the run time. Tinkerers may want to make up their own 4.0, 4.4, or 5.0 amp hour NiCd battery packs. But that means carrying more weight. If I were making a metal halide lamp for my own riding purposes, I'd have made one with a 10 watt power consumption, to allow getting more time out of a given weight of battery pack at the expense of having somewhat less light (but still more light than most if not all previous lighting systems). For a ten watt metal halide arc lamp should put out light equivalent to a 40 watt halogen bulb. This would be better for the kind of longer night road riding I do.
Unfortunately, metal halide arc lamp technology is such that the 21 watts is currently the very smallest size bulb available. CatEye is, I am told, quite well aware of how nice it would be to have a 10 watt metal halide arc lamp system, and is doing what it can to encourage production of the type of bulb that would make this possible. However, we're not likely to see such a system for a year or two, for such bulbs are yet to even be designed by any of the arc lamp bulb makers.

(2) Battery Charger.
One would have thought that a system employing state of the art electronics for powering a miniature metal halide bulb would also have state of the art electronics for charging its NiCd battery pack. Not so. This thing uses the simplest possible NiCd charger: An unregulated DC supply, with current limited by a series resistor. This nicely charges up a drained battery over night, but if left attached after being charged the battery gets warm. The battery will without doubt suffer injury if left connected for days and days. This charging system is no worse than any of the other chargers for NiCd batteries that come with standard Night Sun, Night Rider, or other high end systems. However, it would have been nice if CatEye had paid as much attention to providing a quality "smart" charger circuit for battery charging as they had to their sophisticated metal halide bulb electronics. That would then allow charging the battery in a few hours, AND allow leaving it hooked to the charger indefinitely without harm to the battery, AND allow the battery to be kept at full charge (instead of self-discharging while disconneted... a real problem with NiCd batteries). I do understand CatEye's failure here, tho: Even tho integrated circuits such as the MAX 713 and Benchmarq / MAX / Unitrode 2003 chips are now avialable to do "smart" battery charging, building up a circuit to charge 2 to 5 amp hour batteries quickly is expensive. It would have added $50 to $100 to the retail price. And the Stadium lamp is already very expensive.

(3) Packaging.
I think it would have made more sense for CatEye to have packaged the electronics and the light bulb in the same housing, so as not to have a high voltage cable leaving the handlebar unit. I don't think riders are at any real risk with CatEye's exisiting arrangement, but their design seems to me awkward. Perhaps they were concerned about the light producting so much heat that the electronics would be compromized, tho my own tests of the system suggest that problem would not be insurmountable if one designed the package correctly.

(4) Price.
$400 is a LOT of money for a bicycle light. This alone will for a while make this a very low volume, speciality item. As I understand it CatEye had WANTED to be able to sell the thing for $300 retail, but ran into greater costs than expected in obtaining the metal halide bulb, among other things. However, although this light costs almost twice as much as current common high end systems, it is OVER four times better... and provides enormously greater safety. I suspect that after riding with someone who owns one, a lot of folks who initially said to themselves "That's a nice concept, but there's no way I can justify investing that much money in a bike light" will change to "This thing is WORTH it." That's exactly what happened to Zach Kaplan when he rode with me. Certainly when this lamp is on the market, anyone considering spending $250 for an incandescant bulb type of high end cycling system would be strongly advised to check this out. The extra $150 or so is not that much for the enormously greater safety and utility this lamp offers.

(5) Too Bright?
The CatEye Stadium light is literally blindingly bright. If angled injudiciously, it can really annoy approaching car drivers and pedestrians, in much the same way a badly angled car bright headlamp beam can be blindingly annoying. Zach and I had this fact underlined when we approached a large group of pedestrians on a bike path in Marin, who cringed and shielded their eyes as drew close. I called out "Greetings, Earthlings" as I rode by, but the fact is they really were somewhat annoyed by the intense beam from the Stadium lamp. Those who use it will have to be very conscientious about how they mount and angle this lamp. It would be nice if there were a means of dimming the lamp when one sees an on-coming car or pedestrian. As I understand it, this cannot be done electronically, so perhaps a mechanical iris or shade could be installed. It would not suprise me that if metal halide lamps become common on bicycles, legislation will be passed regulating how they may be used, much like existing legislation governing the positioning and power of lights on cars.

(6) Psychology and Esthetics.
Tho in some ways superior for lighting up road flaws, the cold blue-white light from the metal halide lamp is less psychologically pleasant than the light from a warm yellow-white halogen lamp. This does tend somewhat to alter the esthetics of night bicycling. The extremely wide area of illumination does make for much greater safety, but it also removes that sense of "silently rolling thru a tunnel of light thru the night". The night riding experience becomes more like riding during the day. Honestly! I know this sounds silly, but that effect is NOT all good. There are things about that sense of being wraped in darkness on a country road at night, seeing only the road ahead, that I kind of like. If one is riding very slowly, the added safety of the bright, wide beam CatEye is not really that much of a factor. I might well continue to have a lower power (6 watt or so) halogen bulb based system on my bike with the Stadium lamp, both to better husband battery power on long uphill climbs, and to provide the option of savoring that primative, firelight-like feel of the light of the "obsolete" halogen bulb.

---marty