No year-round commuter bike is complete without lights, and no commuter bike is more of a car replacement than one outfitted with an always-available, dynamo-powered lighting system. In the past, we’ve owned bikes with dynamo systems, but in recent years we’ve relied mostly on battery-powered LED (light-emitting diode) lights and rechargeable batteries. This is mostly due to the fact that we have so many bikes coming and going that it makes sense to use removable lights, but it’s also because we’ve been waiting for dynamo-powered LED lights to mature. With our new commuter build project this year, the time was right to invest in a new dynamo system.
Dynamo lighting systems include a headlight, a tail light, a generator, and the wiring to tie it all together.
Power sources used in dynamo lighting systems include hub generators and sidewall generators. Hub generators are built into the front hub and use the rotation of the hub to generate electricity. Sidewall generators mount on the frame and use a roller that presses against the tire to generate electricity. Hub dynamos are much more popular than sidewall dynamos, at least here in the U.S.
The quality of dynamo-powered headlights and tail lights has improved dramatically over the past few years, mostly due to the advent of high-efficiency LED light emitters. In the past, low-output halogen lights were the norm, but the greater efficiency of LEDs has taken dynamo systems from “barely good enough” to “far more than sufficient”.
While dynamo lighting systems offer a number of advantages, they’re not without their drawbacks:
Always available, instant-on lighting
Run on human-powered green energy
Permanently attached to bike (difficult to steal)
Limited to use on one bike
Wiring and set-up can be tricky
The Supernova E3 Pro is a latest-generation LED headlight driven by a CREE XPG R5 LED. The emitter is housed in a rugged casing machined from 6061 aluminum alloy. Total output is 370 lumens, with a 5 minute standlight built in.
The E3 Pro is available with one of three mounting systems: the “Lefty” mount for disc brakes; the “Multimount” for V-brakes (or calipers with the addition of the optional adapter); or a handlebar mount. By removing the mounting arm from the Multimount model, the light body can also be mounted on a standard 6mm rando-type mount as shown in the accompanying photos.
The E3 Pro is available with either a Euro-style, asymmetrical “Terraflux” lens, or a more conventional, symmetrical “Iris” lens. The Terraflux model produces 305 lumens in a controlled beam that directs most of the light toward the road surface. The Iris model produces 370 lumens in a round beam that disperses the light more evenly above and below the light source. We opted for the Iris model.
The E3 Tail Light has a trio of 5mm LEDs set in a housing that, like the headlight, is machined from 6061 alloy. The housing is designed to fit 50mm Euro-style tail light rack mounts such as those supplied on Tubus racks. The LEDs are powered by a wire connected to the headlight, which also provides current for the 10 minute stand light.
The E3 headlight and tail light are supplied with long wires with bare ends that have to be cut to length and fitted with the included connectors. Supernova also sells optional quick release connectors to facilitate easy removal of the lights (see photo below).
Wiring a tail light can be a tricky. Some custom builders and at least one mainstream manufacturer route tail light wires through the frame. When a dynamo tail light is added aftermarket, the wire should be carefully routed along cable paths and attached to the frame at strategic locations with small zip ties. In the case of our project bike, the wire was routed along the rear shift cable, then up along the main vertical strut on the rear rack.
The E3 Pro headlight is noticeably brighter than the battery lights we’ve been using the past couple of years, including the Planet Bike Blaze 2W, Fenix LD20, and Princeton Tec EOS. It fully lights up even the darkest roads and I feel it’s as bright as any headlight needs to be for commuting. The round Iris beam is not as focused as the Terraflux beam, which may be a disadvantage in the city where there’s lots of ambient light, but it more effectively illuminates shoulders and around curves on dark roads in rural areas.
The E3 tail light is not as bright as the Planet Bike Superflash tail light we’ve been using the past few years. The question is whether it’s bright enough to be safe. The answer is somewhat subjective, but I’ve ridden behind the little E3 and it certainly seems bright enough to me. Be aware that it’s not recommended to mix Supernova headlights and tail lights with other brands of dynamo-powered lights, so if you prefer a more eye-catching rear light, I’d opt for a battery-powered flasher such as those from Planet Bike or Portland Design Works.
Shimano Alfine Dynamo Hub
Most modern dynamo hubs work pretty well. Like other hubs, high end dynamo hubs will tend to last longer, roll smoother, and weigh less than their less expensive counterparts. The Alfine is a high-performance dynamo hub from Shimano built with Ultegra-level parts. It runs with relatively low drag (I can’t feel it at all), and it will power any 6-volt headlight and tail light without issue.
As you can see in the photos and discern by reading the specs, the E3 lights are beautifully constructed. The machined housings and other fittings are quite robust. The CREE LED emitters provide more than enough light for commuting and should outlast almost any bicycle. I’ve yet to test the system in the rain, but so far it’s been flawless (I’ll follow-up this winter with a wet weather report). I’d forgotten what a pleasure it is to have instant-on, always available lighting without the need for batteries; the only problem now is that I have to start saving pennies to set-up our other bikes with similar systems!
E3 Pro Headlight
- Maximum Brightness: 370 Lumens
- Stand Light: 5 Minutes
- Lens Type: Iris (symmetrical)
- Emitter: CREE XPG R5 LED
- Dimensions: 65mm x 45mm
- Material: 6061 Aluminum
- Weight: 130 grams
- Price: $205
E3 Tail Light
- Stand Light: 10 Minutes
- Emitters: 3 x 5mm Red LEDs
- Dimensions: 60mm x 11mm x 15mm
- Material: 6061 Aluminum
- Weight: 20 grams
- Price: $60
Shimano Alfine Dynamo Hub
- Width: 100mm OL
- Spokes: 32
- Brake Mount: CenterLock
- Price: $120 (plus the cost of a wheel build)