|Looking into the reflector: LEDs point down, not out, part of the engineering of a sharp top beam cutoff|
A prefatory note on one of the motivations for this post: I read the review of the B&M Luxos U Dynohub-powered light in the Winter 2013 edition of "Bicycle Quarterly," and felt like writing a rebuttal to its conclusions.
Brief rebuttal: Philips SafeRide battery-powered LED Bike Light (LBL) currently selling for $79.99 on a popular e-commerce site***. This single sentence answers the majority of anti-battery light assertions/rants in the BQ article.
Longer rebuttal: for city riding and commuting, you would be hard-pressed to find a better or more suitable light than the Philips LBL and furthermore, you don't need to spend $900+* on a dynohub lighting system around the B&M Luxos in order to achieve excellent lighting for your bicycle riding for those applications. To be clear and transparent, in contrast with the BQ article, the LBL as it comes out of the box may not be the right solution for a more demanding application like long-distance randonneuring across remote mountainous regions at night. But the distinction should be made that most city riding and commuting is a quite different application with different and in many ways less demanding requirements than long distance solo randonneuring**. If that's your sport or passion, a $900+ dynohub lighting system/wheel probably fits right into the rest of your bicycle system. Also, for both applications, beam shape does matter. Other than those two conclusions, I disagree with most of the sweeping, generalized statements made in the BQ article about bike lighting. A fair comparison between the Luxos and the LBL for city riding and commuting would reach very different conclusions, I expect. (see W.Scholten links below for superior, excellent, detailed reviews and beamshots)
|My LBL being fully charged (but not running, which doesn't work) off a portable 11Ah Li-poly supply @2.4A and 5v|
My Perspective on bike lights (criteria for success): A bicycle headlight should be bright enough to illuminate the road ahead and to the sides, with a beam pattern that efficiently throws light where it's needed, and not where it's useless and/or annoying, should enable drivers of oncoming as well as side-entering vehicles to see the light and to accurately gauge distance and to read "cyclist", and should have a power source and overall reliable construction which does not leave the cyclist inconveniently without a working headlight.
As if those requirements are not demanding enough, I also add on that it should be as economical as possible given current lighting (high power LED) and power source (rechargeable batteries or dynamo) technologies, and, should fit into a loosely coupled overall bike system design (more on that below). Additionally, it should either be easily mountable and removable, or alternatively, so securely mounted and/or ugly, that either way the probability of theft while parked at the bike rack in Phoenix, AZ, a city with a high level of theft of bicycles and parts, is low. The best light stolen is equivalent to the worst light mounted. Finally, the light should satisfy these requirements in the context of city riding and commuting, as those are my main applications.
|Side view of the Philips LBL. It's not small, but in my opinion not overly large for its purpose|
The Philips SafeRide LED Bike light nails all of these criteria for me, in a commuting application. On another hand, a $900+ dynohub+wheel+B&M Luxos leave-on-the-bike system is not for me, primarily due to cost vs. benefit for my application, and also because I do not feel secure leaving it at the bike rack in a medium to high crime big city where cable locks are cut off so frequently that using one at the bike rack makes theft within the year automatic. For a very thorough series of review and comparisons with competing lights, please go have look at W.Scholten's articles below. This reviewer is without parallel as far as I have encountered, and rates the Philips LBL very high in comparison with other current lights, specifically, a notable void in the BQ article:
W.Scholten Main lighting review page
W.Scholten: Amount of light on the road from a circular (most battery) headlights
W.Scholten: Philips LED bike light (LBL), battery powered, with cutoff
W.Scholten: Comparison with possible competitors to the LBL, including dyno lights
W.Scholten: Busch & Mueller: Luxos B & Luxos U dynamo headlamps
There's also interesting stuff on the Candlepower Forums thread about it, but the quality varies there.
Here are a few salient observations about why I like this light so much for commuting and city riding, based on two months of usage. The 4AA NiMH batteries supplied with the light are easy to charge, and in typical commuting for me, running in "eco" mode and not in bright, have me recharging about once a week. The blue lights tell me when I need to recharge, and I just plug it in when they tell me too. The light itself is bright, but with the strong top cutoff, only throws where it needs to, and not into space or into the eyes of motorists or other cyclists. In this respect, I'm a convert to the necessity of a strong top cutoff beam for bicycles. Also, when the time comes, 4AA NiMH batteries are economical to purchase, and easy for the end user to replace. On the other hand, as I mentioned in the photo caption above, they recharge nicely off a portable power pack, but the light doesn't operate while plugged in, so you can't easily run it off an external pack, as far as I (and others who have tried) can tell. That's too bad, since the 2.4A @ 5v coming out of my $40 Lipoly pack above should easily be able to power it, which would serve as a backup and reassurance for running out of juice somewhere inconvenient.
When I unpacked the light initially, I charged the 4AA batteries in my LaCrosse BC-700, which charges cells separately, at 200ma for a charge-discharge-charge cycle to try to get all the cells to a roughly equal charge. Out of the box, there was indeed one cell at a much lower charge state than the other three, which is typical in my experience. I will probably repeat this equalization process once in a while, since 4-cell AA packs always seem to get out of sync eventually when charged together as a pack. Otherwise, though, I am just plugging the light into a USB charger and so far, having good results with that.
For future consideration in a blog post, and relevant to this one: mounting height as well as the aiming of a headlight, bicycle or otherwise, has direct and significant effects on many of its important lighting characteristics, yet very little instruction is typically provided on how best to mount or aim them. For lights designed to have a sharp cutoff on the top, it seems that the top of their beam should be aligned with the horizon to provide maximum lightning benefit while also taking advantage of the cutoff characteristics. And once you get that height and aim dialed in, does the supplied mount maintain it? This is one more possible knock against removable lights compared to permanantly mounted ones, since every mount I've used so far, including this one, moves when you put the light on or take it off, requiring re-aiming every time.
|Examples of badly aimed unscientific beam shots to give some idea of eco vs. high (eco)|
|(High). Beam should be aimed higher than this. On a dark street, bright easily illuminates 60 yards ahead.|
Another characteristic I appreciate is that the light body is constructed solidly of metal, and everything fits together firmly, with little or no rattling for me. So far the switch remains consistent and reliable. The light stays put once mounted, although the mount does move when you install or remove the light.
What did I mean by "loosely coupled bike system," above? An example of a tightly coupled bicycle system would be one with an electric assist, large battery storage, and regenerative charging from all relevant moving and stopping interfaces: brakes, pedaling while going downhill, generation while rolling downhill itself, and potentially even seatpost motion, handlebar motion, and a regenerative suspension. The point about such a system relevant to this post: one faulty, difficult to find component could easily render the whole bicycle unridable, and depending on which component fails, very expensive to repair. Tight coupling in any system yields pervasive impacts from single point failures. In addition, replacing or upgrading one component requires compatibility, along with consideration of all other tightly coupled components so that the repaired or upgraded whole will still work as intended.
This is most commonly addressed by requiring that replacements or upgrades are done strictly with proprietary, compatible replacements. An example of a tightly coupled lighting system is one in which the operation of the lighting system depends on the rotation of the wheel, and the rotation of the wheel is affected by the operation of the lighting system. An increase in resistance in one, a corroded connection in the wiring for example, will cause an increase in resistance in the other (rolling resistance with light turned on, for example). A failure in one, for example a shredded tire in the middle of the night in the middle of nowhere, will cause immediate or in some cases slightly delayed failure of the other. So, just to be clear, the Philips LBL and other battery-powered lights with self-contained power sources are loosely coupled, since you can put them on and take them off without affecting much if anything else on the bike, except possibly other things already mounted in the handlebar area.
I could go on about this, but I also wanted to show you a much older example of an attempt to shape the beam of a bicycle headlight: the Specialized PreView XE from a couple of decades ago. It operates on 4AA also, but requires 6v to operate and overdrive the 4.7V xenon lamp, so NiMH are hit or miss, and don't work very well with their nominal 1.2v per cell. Back when I used it, I relied on "high capacity" NiCads, which still started off with a lower voltage than 4 alkalines, but which seemed to last longer before the red indicator LED triggered.
|Older, shaped beam bike light|
|Unscientific ceiling beam shot of the old Specialized PreView XE incandescent light (squelched and weird and not really this white)|
|Unscientific (not exposure equalized) ceiling beam shot of the LBL, illustrating the artifacts others have mentioned|
This is a light made for bicycles which has the advantages of engineering by an experienced automobile light company. Many users have likened it to a car or motorcycle beam, and I agree. By putting light where you need it, and not where you don't, it both uses it's available lumens to greatest advantage, making it seem as bright as much more powerful symmetric round lights, and also minimizes the dazzle into the eyes of other road users (when aimed properly). With such a sharp cutoff, I wonder if those artifacts actually serve the purpose of increasing visibility of the light by drivers. Do they look like crab legs to anyone else? Though I always carry a backup light (and tube, and tools..), this has become my primary for night and early-morning commutes. I haven't been flashed once by oncoming drivers while using it, or gotten any negative feedback from other cyclists or pedestrians, which is indeed a contrast with the kind of comments I get when using one of my bright and symmetrical, round beam battery lights. After experiencing, I have to agree that's a good thing.
*B&M Luxos U $235 + SON 28 hub $300, new wheel of similar quality as lighting system built around hub $350 and up total cost: close to $900.
I purchased this light with my own funds and received no consideration for writing this. Please see my disclaimer if you have any other questions, and for more information.
**One may consider bicycle commuting as a version of long distance solo randonneuring, which just happens to have very regular and lengthy rest stops. Rest assured there's no penalty for recharging your bike light during these rest stops while commutanneuring.
***this amazing price may representing something like the North American closeout or End of Life pricing for the first version of the light which has a blue LED charge gauge on the top. I write that as if I actually understand or know what the differences are between the versions of the light, or whether they are in some official sense to be referred to as Generation 1 or 2, or version 1 or 2, or how the ball joint mount or high power timer electronics actually figure into the naming, but in spite of dedicated searching and reading, I could find no clear listing of what's what with what version or generation or whatever. It's clear that as time passes, Philips is making changes to this light. Also, I like the one I got.