Bike Lights: How Bright is Bright Enough?
Thinking back on my shop days, I’m still filled with surprise on how often I had to recite the first noble truth of outward illumination to customers. It goes something like this: there are two kinds of lighting setups in the world, ones that let you be seen and those that allow you to see. And not surprisingly, given that we were always discussing a noble truth of retail and not the spirit, the prices between the two paths always varied greatly. At times, introducing words like “lumen” to the average customer’s vernacular made me feel like I was introducing them to the concepts of hydrogen. And for those whose minds still lived in the power rating of “candlepower,” I might as well have been describing up quarks and gluons. But let’s be honest, light exists with some duality. You flip the switch, and you can read this article. Simple. Yet, at the same time, its speed is unsurpassed in the universe. So it shouldn’t be surprising that the manufacturers who’re harnessing this power tend to have a difficult time striking the balance between marketing lingo and the science behind their products. In other words, it’s okay if you’ve never used lumen in a sentence; I have, and I’m here to help.
This leads us to the discussion at hand. The common misconception is that the larger the attached integer, the brighter the light. On the surface, there’s truth in this. However, no one wants to be in a pace line with a 1200 lumen light blasting them from behind. However, if you’re a late night trail rider, this power is ideal. The real power in, well, determining your power is context. Determining your usage is the lynch pin in determining your output, light position, and setting requirements. So, let’s take a look inward and see what kind of rider you are, and accordingly, what you really need.
The “Oh-sh*t, I Forgot Rosemary For My Casserole” User
You fall into the “be seen” category, and you’ll need front and rear lights that attach easily, announce your presence to motorists, and just as importantly, have hassle-free removal for when you pop into the store. For you, the ominous-sounding “hipster cysts” will suffice, given that you’ll be venturing into the dark only on rare occasions. In the accessories department, you’re better off flexing your dollars on carbon Arundel bottle cages—a wise choice.
The After Dark Base Miles User
In the winter months, you feel chained to your desk from sun up to sun down. However, to you, the indoor trainer is about as appealing as doing jumping Jacks in a sauna. In this scenario, seeing where you’re pointed is just as important as being seen, so you’ll need something in the range of 200 to 500 lumen.
400-lumen Test, Photo Courtesy of Light & Motion
For reference, the average car’s headlight has an output of around 200-lumen, but its beam is far wider than that of a typical bike light. Keep in mind, though, that the integer on the label is usually a light’s maximum setting, which fittingly uses the maximum amount of battery life. As a result, the lifespan on a maximum setting is considerably shorter, which means that you’ll spend a majority of your time on the Medium settings. If your routes are assisted with street lamps, cutting your output in half will be fine. But if you’re situated in a more rural environment, you’ll want to gravitate towards the 500-lumen and up category.
In terms of mounting, the handlebar will be ideal for you. After all, a helmet mount means that your point of projection will be higher, which will agitate nearly every motorist on the road. Aside from irritation, riding with cars on the road dictates that you’re looking around 50 feet ahead, so having a fixed point of projection is actually ideal.
The Lonely Mile User
Touching on the rural setting from above, your roads are choppy, your descents are twisty, and the probability of crossing paths with a deer is pretty high. A handlebar mount will still suffice, but you need to be cranking up your output closer to the 1200-lumen mark. Simply put, you can’t afford any surprises.
800-lumen Test, Photo Courtesy of Light & Motion
At the maximum setting, your lumen output will rival a car’s high beams, only without projecting at the same vertical extreme. Also, keeping in mind the shorter life of max settings, you’ll be left with a solid, high-lumen beam for long training rides. And depending on how beat up your roads are, you might want to take a few notes from the next section.
The Trails Are Empty at Night User
Like the Lonely Mile User, you’ll want to focus on 1200-lumen and above lights. Where you differ, though, is that you should be running two lights—one helmet mount and one bar mount. The principles of the bar mount are the same (forward projection), but trails aren’t roads.
Helmet mount trail projection
With trees, switchbacks, and inconsistent surfaces, mountain riding dictates that your visual focus is far closer to the bike than it is on the road. So, you need a light that supports your line of sight. However, your line of sight isn’t always what’s ahead of you, which is why the two-light-setup is ideal for trail riding.
The Endurance Racer
Again, you’ll want to stick with the double light arrangement, but your power needs to gravitate towards the “all that you can get” category—Light & Motion makes a 2000-lumen light that I would suggest to you and only you. You’ll also want to invest in some backup battery packs and spare mounts. And when you’re using a light of this power, be diligent in optimizing your various output settings, as overheating can sometimes occur.
2000-lumen Test, Photo Courtesy of Light & Motion
Well, there you have it. Bigger isn’t always better, and you’ve learned this without memorizing any formulas or graphs. Use some common sense out there, and don’t forget those taillights.
Trail Photos: Ian Matteson