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Help Me Choose A Headlight
Prisoner at War wrote:
Not sure how I'd prevent their being blinded, anyway: I couldn't predict it, could I? But I'm sure the two HIDs I'm considering have some kind of optics which should mitigate such circumstances. They better, anyway, for $600!!! In reality, the optics on the higher end bicycle lights are excellent. It's not a wild unfocused beam such as on the old 2 D cell battery headlights of the olden days. The quartz-halogen lights are typically using MR lamps, which are very good optics with matched, mirrored reflectors. Most bicycle and motorcycle HID lamps also use MR11 and MR16 type lamps, as it's become the super-standard for high-end lighting. One of the big advantages of the MR system is that the bulb is aligned precisely with the reflector at the factory. One problem with the lamps where you replace the actual bulb is that you have to align the bulb by trial and error (not even possible on the cheap lamps with threaded bulbs, and a hassle on the higher end lamps with a bulb that can be rotated for proper alignment). Look at HID lamps on vehicles. If aimed properly, the low beams don't blind you. Contrast this with some of the crappy daytime running light implementations that use the high beams at half-brightness, and blind you even though the lights are not really all that bright. So which one do you recommend? Looks like the NiteRider is a winner. Funny how I can't really find reviews of these guys online. I've seen only one "real" (i.e., useful, with a good photo) review of the Light & Motion product, but none yet for the NiteRider (which is newer, though). Anyway, a good reminder, your post. I almost never feel the need for a light, but all club rides require them (except the anarchist Time's Up! rides -- hooray!), and, in keeping with my nature, if I get something I'd like to get the best. ^_^ (Yes yes I know "the best" is a semantically ambiguous term....) (Yes yes, I know, " You really have to look at them to evaluate them. Do any have a metal mounting bracket to the bike? How rugged is the wiring and the switches? How much will battery replacement cost? How much is a replacement lamp? Most of these systems use the MR11 Welch Allyn HID lamp, which costs close to $90, and you definitely want to have a spare. There will soon be a flood (no pun intended) of lower-cost replacement HID lamps coming in from Asia, you can already see them on the manufacturer's web sites. |
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#62
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Help Me Choose A Headlight
On May 7, 12:41 pm, SMS wrote:
Prisoner at War wrote: Not sure how I'd prevent their being blinded, anyway: I couldn't predict it, could I? But I'm sure the two HIDs I'm considering have some kind of optics which should mitigate such circumstances. They better, anyway, for $600!!! In reality, the optics on the higher end bicycle lights are excellent. It's not a wild unfocused beam such as on the old 2 D cell battery headlights of the olden days. The quartz-halogen lights are typically using MR lamps, which are very good optics with matched, mirrored reflectors. The optics of MR lamps are excellent for their primary intended use: track lighting, to properly display paintings on walls, or to give supplemental or decorative lighting inside houses and buildings. For those applications, you want a soft, even, radially symmetrical beam pattern. The optics required for road use are entirely different. Park your car in front of a wall and examine the shape of the headlight beams on the wall. Rather than a radially symmetrical beam, you have a precisely tailored beam shape. The most notable feature is the horizontal cut-off plane, with bright light below that plane (to land on the road) and dimmer light above that plane (to prevent blinding of other road users). There are legal requirements - at least, in many countries - governing the shape of the beam. Most bicycle and motorcycle HID lamps also use MR11 and MR16 type lamps, as it's become the super-standard for high-end lighting. AFAIK, motorcycles are subject to the same legal beam requirements as other motor vehicles. Certainly, my BMW has a beam shape that's tailored as precisely as my car's lights. I seriously doubt any radially symmetrical HID lamps are used as original equipment on motorcycles, but I'm willing to look at properly cited evidence to the contrary. Now it's true that aftermarket light sets have no road-tailored optics. Those are the ones installed by irresponsible hot-rodders, the ones that blind oncoming traffic. One of the big advantages of the MR system is that the bulb is aligned precisely with the reflector at the factory. One problem with the lamps where you replace the actual bulb is that you have to align the bulb by trial and error (not even possible on the cheap lamps with threaded bulbs, and a hassle on the higher end lamps with a bulb that can be rotated for proper alignment). Statements like that make me wonder about SMS's experience with lights! Bike generator headlights use flange-mount bulbs. The flange-to- filament distance is precisely controlled. When replacing a bulb, the flange sits against a precisely placed shoulder. The shoulder has a protrusion, and the flange has a matching notch, so the bulb fits only in it's precise orientation. No trial and error is necessary. In fact, it's not even possible! You really have to look at them to evaluate them. Do any have a metal mounting bracket to the bike? How rugged is the wiring and the switches? How much will battery replacement cost? How much is a replacement lamp? Most of these systems use the MR11 Welch Allyn HID lamp, which costs close to $90, and you definitely want to have a spare. IOW, add $90 onto the already exorbitant cost of the HID set you're considering. Through all this, I think it's good to remember that motorcycles travel legally up to 75 mph. Their headlights are designed for such speeds. Using that light output for a bicycle is as inappropriate as using motorcycle wheels on a bicycle. - Frank Krygowski |
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