The EYC N PLUS From Busch and Muller with a custom mount.

Now that we are well into daylight savings time, it’s probably a good time to talk about lights. Or more specifically, dynamo lights. Regardless of your specific goals on the bike, if you’re riding year round you are probably pushing daylight at times. If you’re anything like me you have at least one someone at home who worries about you. Or maybe you’re reading this and thinking about someone who does ride at dusk or later this time of year.  Maybe they are commuting to work by bike. Or perhaps, they are just trying to squeeze a workout in between the day’s responsibilities.

If this sounds familiar, pay attention.

The EYC N PLUS From Busch and Muller with another custom mount.

If you (or that cyclist you love) is not using a dynamo powered light, you're simply doing it wrong. I was once like you. Using battery-powered or rechargeable lights, but one day I saw the true light and embraced the righteous power of the self-powered light.

Kidding aside, you really should consider this as an option and here is why:

Dynamo lights are powered by a specially designed front hub/wheel.  As the wheel turns it generates an electrical current. Through the miracle of science, this electrical current is harnessed to power a light (or a USB charging device). First and foremost, this means never worrying about recharging that headlight or replacing batteries. Heck, if you’re like me you don’t even worry about turning the light switch on or off. When you start rolling the light automatically turns on. Day or night, when you start to ride, that light is going to automatically turn on. Like daytime running lights on a car, this is nice for obvious reasons.

Always having a light on (or ready to turn on) no matter the light conditions is certainly a pretty awesome thing. However, it’s not the only advantage dynamo lights have over rechargeable lights.

German engineering. Often synonymous with quality and ingenuity, it holds true here. The German STVZO standard could benefit from its own long-winded blog but here’s the quick and dirty version. The majority of non-STVZO bike lights produce a cone-shaped beam. While this is pretty great for off-road riding where you want as much light as possible directly in front of you, it has some drawbacks for road or bike path riding. A cone-shaped beam (especially a powerful one) often results in putting light right in the eyes of oncoming motorists or other cyclists.

The IQ-X from Busch and Muller at 100 LUX

Think about low beams and high beams on your car. Unless you’re a bit of a sociopath you probably use your low beams most of the time. Why? Because we know from experience that encountering an oncoming driver using their high beams makes is hard to see the road or possible obstacles.  STVZO lights work the same way. Rather than a cone-shaped beam, the light is refracted into a more rectangular shaped beam. First and foremost this beam has a “cut off” at the top. This where it’s going to get confusing for a second. The STVZO standard is measured in “LUX”, not “Lumens” (I’ll get into this more at the end). Lux and Lumens are NOT the same thing1. Regardless of max beam power, a STVZO light can’t produce more than 2 LUX at the top of the beam. This is measured 3.4 degrees above the brightest point of the beam and what it means is that when properly setup a STVZO light, much like an automobile light, puts the majority of the light on the road ahead and not up in the eyes of oncoming traffic. This means the light is safer for everyone2.  

The EYC N PLUS  from Busch and Muller at 100 LUX

The other advantage of dynamo lights is that they don’t flash. It has been suggested for some time that a bright flashing light can confuse oncoming road users. Not only is it harder for our eyes and brains to determine the distance to a flashing light compared to a steady one, but it’s been found that a steady beam is more likely to be recognized as an oncoming vehicle rather than something else. Ideally, if you are riding in traffic, you want motorists to assume you are another vehicle and be able to gauge how far away you are and how fast you are approaching. Those bright strobing lights actually work against this. Crazy!

The other nice thing is that you’re not blinding other cyclists or pedestrians. I speak from experience riding on the bike path at night here, if you’re blasting a 2000 lumen strobe, you’re being a jerk. Sad but true.

Lastly, STVZO lights put more light where you actually need it. The beam is typically refracted into zones with varying brightness based on what you need to see mosts. This is hard to accurately explain or photograph, but you’re welcome to come by and spin around after dark on one of our dynamo equipped bikes to see what I mean.

Anyway… I’m starting to ramble. Let’s get back on track.

So, dynamo lights are functionally superior in every measurable way for road and path riding. What are the drawbacks?  To be honest, none. While it is true that the dynamo hub does suck up a bit of the energy you are producing (and thusly making your bike slightly less efficient) it’s not much.  If you’re cruising along 20mph and you have your light on the hub is sucking up about 7 watts of your power3. Switched off? About 1.5-2 watts.  So not much. Should you leave a dynamo light on and shining on a bike if you’re doing a road race, triathlon or fast group ride? Well… probably not. Should you leave a dynamo hub on for literally any other form of riding? Yep.  I’ll take the extra visibility over a tiny bit of efficiency any day.

Last but not least, what’s the price? A reasonable question with a reasonable answer. Adding a dynamo light system to your bike doesn’t have to break the bank. A whole wheel and light system can be under $300 and even balling out of control on the lightest and lowest drag hub and a super fancy light won’t push things much over $500.

The bottom line is that unless you retreat into the garage to do some Zwifting when the days get short, you should be seriously considering a dynamo light system this year.

Here are some examples of stock dynamo builds we offer. Click Me!

1. Lux vs Lumens.  This is where things get funky.  Most single beam “American style” lights are measured in Lumens.  This is the “total quantity of visible light emitted by a source”.  This is usually taken from where the light from the LED or bulb passes through the lens on the light.  It’s a good way to measure simple cone-shaped beams.  A 1000 lumen light makes a cone-shaped beam that is 10x brighter than a 100 lumen light of the same construction.  Simple.  LUX which is how STVZO lights are rated and is quite different.  LUX is the amount of light reflected from an object at a fixed distance. The numbers associated with this measurement are “lower” but don’t correlate to the higher numbers of Lumens.  Confused yet? Me too.  The takeaway is that STVZO lights can be broken down by their LUX rating to give you a basic idea of what lights are brighter.  100 LUX > 40 LUX.  But it’s important to understand that lights that have a higher LUX rating generally have a more sophisticated refractor and lens which not only means more light but MORE light where you want it.  More info can be found on Peter White’s Website  or on Wikipedia 
2. More info about STVZO lights can be found Here 
3. Cyclingabout.com published a great article about dynamo drag Here