October 2, 2007

From the Archives: Commuting Lights

2011.11.20:  Update:
It's simply remarkable the amount of advancement that has occurred in the field of LED emitters and battery technology.  While some of the items in the post below are still accurate, this definitely needs revisiting and will be fully updated with a new post soon.
For now, hopefully this will give you a chuckle or two - but the entire discussion on generator hubs and "see with" vs. "be seen" is still very valid in practice, as well as the importance of passive, retro-reflective materials.


It’s been several years since my last update to the lighting section, and many – MANY – changes have occurred, while other things have stayed the same.
There is a dizzying array of lighting systems available for the front of your bicycle – but most importantly they can be simply divided into two groups:

Lights to BE SEEN with, or, lights to SEE with.

To quell the argument, it’s necessary here to state the obvious: most lights bright enough to see the road with will also afford enough ambient scatter to allow motorists you see you as well. Lights to BE SEEN with, however, are not strong enough to light the road ahead of you in pitch dark, but provide you with an extra margin of safety in low-light conditions. These lights are often small, LED loaded, and have long run-times – very similar in design and scope to a tail-light, only with a white LED or lens. Many commuters choose to use one of these REGARDLESS of whether or not they have a primary headlight, simply because of the way some lights TO SEE THE ROAD WITH are designed: if your primary headlamp has a narrow “spot” beam, and doesn’t radiate excess light or is pointed down to light the path ahead, it’s possible that the strongest portion of your beam is just enough off axis to be practically invisible to approaching motorists – especially from the sides. Having a to BE-SEEN light mounted on the bars and pointed straight ahead will keep you covered from a visibility standpoint, while your primary light helps you see where you are going.

Primary headlights can be sub-divided into three categories at this point in time: re-chargeable halogen systems, generator systems and self-contained LED systems – or some hybrid of these.

Re-chargeable halogen systems have been around for a while, and are hard to beat; with their higher-output lamps and increasingly compact battery designs, these are the champions of the commute, it seems. They are initially in-expensive compared to a generator system that requires a front wheel purchase, and are easy to integrate to any bicycle. While the older lead-acid “water-bottle” battery models are cheap and still available, Nickel Metal-Hydride and Lithium Ion battery packs are almost the new standard nowadays, and long run-time batteries no longer take up very much space. Paired with efficient Metal Halide light-capsule models, or High Intensity Discharge (HID) lights, the run times increase even more, and you are afforded highly visible and effective lighting that surpasses many automotive systems. Even still, some of these models offer LED modules built-in that allow low-light visibility without sacrificing run-time on the main light. All of this comes at increasing price-points, of course, but the choices are only limited by how much you care to spend, and all systems are tough, water-resistant, and well suited for commutes in any condition.

Generator Systems have been around the longest of any effective lighting system (early wet-cell systems were inadequate), almost as long as the bicycle itself. Tire driven generators have been lighting the way for cyclists long before sealed-lead acid battery technology allowed early halogen systems to emerge, or even the dry-cell halogen or “flashlight” style handlebar-mounted lights. Generator systems have enjoyed a lot of evolution only in the past few years, with the advent of better magnet assemblies, more efficient light bulbs and LED utilization, and cleaner integration. While tire-driven systems are still available (bottle-style generators), the forefront of generator lighting for bicycles lies with the hub generator. By building the generator itself into the hub assembly of a standard front bicycle wheel, the systems instantly became more efficient, less complex to set up, and maintenance-free – all things that should pique the interest of a bicycle commuter. The only drawback that generator systems have is the power limitations: while high-powered halogen systems rely on stored energy and can run as bright as needed with no impact to the ride, the generator system must ultimately be powered by a human – and pushing a bicycle is hard enough on its own. Still, hub generator manufacturers have achieved a level of perfection, and the best systems have so little resistance as to be undetectable. Further efficiency has been thusly designed into the lights that these hubs power. Running at 6 volts and a nominal output of 3 watts doesn’t provide a ton of juice, but with well-designed optics and efficient bulbs and LED arrays, the light these systems put on the road can challenge some cheaper halogen battery systems! Three watts doesn’t sound like much, but my current generator system puts more USABLE light on the road than my old 10 watt halogen system does, and I never have to replace or re-charge the battery. Therein lies the ultimate selling-point of the generator system: no batteries, ever. Halogen systems, while powerful, have on distinct disadvantage in that you have to plug them in every night and be aware of your reserves. If a late-night errand takes you out of the way, or a trip to the pub finds you home after dark when you already commuted to work in the dark that morning, halogen systems might leave you in the dark. While run-times are increasing to upwards of 5-10 hours, those not willing to spend the extra money for that kind of capacity may have to be careful. Generator systems offer you power whenever you need it, and you never have to plug anything in. Coming from the standpoint that all halogen systems EVENTUALLY will need a new cell-pack in their lifetime, at cost to the user, eventually the scale of value will tip in the direction of the generator system. If you are a dedicated commuter, enjoy night rides, and don’t want your cycling dictated to you by a battery meter, then a generator system is something you should consider – and they ALWAYS, eventually, pay for themselves.

Self-Contained LED lights are the latest technological advancement in bicycle lighting, and the future is apparent. Many older-style lighting options, like halogen systems with larger batteries, have their days numbered when these wonders began showing n the market. With the advent of 1-watt, 3-watt and 5-watt LEDs, the user can have a fantastic amount of light from a very small package – and the only concern is heat dissipation and battery life – which is nearly ALWAYS longer than an equivalent halogen system. Even with external battery packs, these systems are compact and powerful, and are easy to move from bike to bike with minimal hassle. With initial systems receiving complaints and reviews that would have them more aptly-placed in the “to be seen by” category, the latest models have improve optics and better circuitry to allow more light to reach the road. The inherent problem with LEDs is the fact they are not a “point-source” generator of light. Unlike a filament in a bulb, which is very easy to build a reflector/refractor array around, LEDs light needs to be handled differently in order to create a usable beam of light that can safely light the way for a cyclist. This is why they have not yet shown up in automotive applications – and it’s highly possible that the technological proving ground for the LEDs’ automotive debut still lies with bicycle lighting – so it’s an exciting time for these products! One distinct plus that LED lights have as a byproduct of their un-focused nature is they do provide a good bit of diffuse light to mark your presence in traffic to surrounding cars – while they may not be as efficient as the halogen and generator systems with regards to light distribution, they make up for it by eliminating the need to an additional “to be seen with” light on your handlebars. Continually improving and changing, these are the cutting edge and are always worth considering – but similar to the home computer market, you will likely be obsoleted at the beginning of each new cycling season as new product continues to hit the market each month. With long run-times, compact housings and good-enough lighting, LED systems are fast becoming the purchase of choice for many commuters.


Even if you never ride at night, a tail-light is a good purchase for ANY bicycle commuter, nay – ANY bicyclist, period.
Brighter is better - flashing functions make you visible in the worst of conditions. You may be out on a particularly cloudy day, or on your way home late in the season when dusk comes faster than normal -- you need to be seen! There are no less than a hundred different types and styles of bicycle tail-lights available, in a myriad of price ranges. This is, like the LED headlight, a market that changes every other week – and what you have available to choose from may well be dictated by what your local bicycle shop carries. It’s impossible for even the larger cycle-supply websites to carry ALL of them. With the options available today, the long run-times, and the styles and sizes from which to choose, the only choice you should make is to simply GET ONE. If it’s bright, runs long, and fits your bicycle and personal preferences, it’s a good buy! Be safe – be seen!


Reflectors: standard equipment on all bikes as required by the CPSC – and often the FIRST thing riders remove upon arriving home with their new ride, they are the oft-forgotten PASSIVE LIGHTING system that no commuter-bike should be without. Taillights are effective for announcing your presence to approaching motorists from a distance, and getting attention (in flashing mode) when the weather turns foul, but headlights from cars can easily wash out the light from your taillight when they get closer to you – although they may likely STILL see you, there is a chance that you may blend into the background until they are right on top of you. In the fall especially, when the sun-angle is lower and it sets earlier in the afternoon, it’s important to make sure you also don’t disappear in the intense glare of the sunlight – this is very important when traveling towards the west in the later part of the day – drivers behind you are already battling with road-glare and a low sun – they WON’T be able to see you as a cyclist until it may be too late for them to react. Although bright colored clothing is a good idea, having a good quality and PROPERLY AIMED reflector is paramount. Many local municipalities require a reflector of some type on your bike, even if they seldom ticket for such things being absent. There are two good methods of getting some passive lighting on your bike, and both should be used for maximum safety.

1) Reflective tape:
There isn’t a more effective way to get some passive visibility than with reflective tape. It will stick anywhere on your frame, and captures and reflects light from a very wide angle. The ONLY drawback to this property is that the light reflected back to the motorist is not at a very high intensity. Still, it is better than nothing at all, and with proper placement can be very effective for object recognition – the drivers brains will fill in the blanks and connect the dots when presented with properly placed reflective material. You will be recognized as a bicycle fairly quickly. Some ideas for reflective tape placement include the sides of the top tube and down tube, back of the seat-stays, front of the fork blades, and the inside of the rims, the ends of the handlebars tape plugs (for road bikes with drop-bars), the backs of the pedals, the rear of fenders, and more. There are no marks-off for being TOO safe or visible. If you are planning on commuting with your ‘good’ bike – or if you just can’t fathom messing up the quality finish of your machine with adhesive tapes, try placing electrical tape on the frame first, and then apply the reflective tape to the electrical tape. Electrical tape stays in place nicely, but is very easy to remove and leaves no sticky residue. Use both white and red reflective tape properly. Make sure you aren’t confusing drivers by miss-use of colors – try to avoid using white on the rear of the bike unless it is ALSO used in conjunction with red, by following the same guidelines that the DOT and highway department recommend for equipment and over-the-road drivers: red is ALWAYS below white on the rear of the vehicle, and red is always BEHIND white on the SIDES of the vehicle: this denotes to approaching traffic which direction you are traveling, and the relation of the back to the front.
Reversing this could give the impression that you are traveling the wrong way on the wrong side of the road!
To avoid this calamity, it is always acceptable to use red only on the rear of the bike. Keep in mind that many seat packs, back packs, and rear trunk bags have WHITE reflective fabric on them – to ensure the best impression to the motorist, keep all of the red materials BELOW all of the white. The only exception would be reflective tape on the pedals or crank arms – since these items are in motion, they will clearly indicate that you are indeed a cyclist – color is not as important. I recommend white for this area, simply because it will be more visible from a distance – and in the case of double-sided pedals, where you never know which side will be pointing where, you don’t want to risk showing RED reflective material towards the front.

2) CSPC-Approved and SAE Retro-reflectors:
These are practically standard equipment on every bicycle sold in the United States these days, and often one of the first things the consumer removes. KEEP THEM, commuters! They capture more light than reflective tape, and are highly effective from a variety of angles. However, just like with LED taillights, they MUST be aimed properly to work. Where reflective tape works at extreme angles, and is therefore perfect for the angled tubes on your bike (stays), reflectors MUST be within a few degrees of perpendicular to the ground and aimed down the center-line of your bike for maximum effectiveness. A few degrees off, and they might as well not even be on the bike. Take extra time to ensure your reflectors are properly aimed!
Where CSPC-approved reflectors are designed for bicycles and are proportionally sized and designed to mount easily, they are not the BEST reflectors out there. Automotive reflectors with an SAE marking on them are larger, and reflect a LOT more light than the CSPC type. Although they are designed for cars, a little ingenuity and extra hardware will allow installation on a bicycle with no problem. Just make sure they are level, and you will be VERY visible from the rear. Most SAE reflectors are larger than true bicycle reflectors, but there are several different shapes and sizes available – when incorporated into a rear fender or rack, or somehow sewn onto a seat pack, they will blend nicely into the bicycle. Remember, though: safety first – style second!

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