Dynamo light reviews

I've found it hard to find English-language reviews of dynamo-powered bicycle lights — usually all I can get is the same copy-pasted marketing text. Here's my real-world experience with the models that I've tried — hopefully it can help you choose the right lights for your bike!

If you're new to dynamo lighting, the idea is simple: a little bit of the muscle power that you use to move your bicycle is converted into electricity to power your lighting system. This is great because your lights never run out of power, they're always bright, and they're usually permanently installed on your bike. In the past, generators often rubbed against one of the tires (feels like riding with the brake slightly on), but now they're often built into the hub of the front wheel (much less drag). Dynamo lights are common in Europe (especially Germany), but relatively rare in North America (though now that I know what to look for, I see them in Montreal often).

Rear lights

Busch & Muller Toplight Line-Plus

The best rear light I've tried. It somehow keeps a charge between rides, and at the slightest power input, it immediately jumps to full brightness and a few minutes of standlight (the 'standlight' is the feature that keeps the light on when you stop moving the bike). It's big and bright. It has a switch to immediately turn it off when parking. I wish I could figure out a lower-profile wiring option because the spade connectors hang off the light (below my rack) and get jostled and bent occasionally (the photo below is right after one broke actually).

Busch & Muller Secula Plus

My favourite mud-guard mounted light. Standlight stays on for 4-5 minutes, light is quite bright. Cables come off the bottom at a bit of a weird angle (pointing to either side of the bike). I've tried the seat-post mounted version and it's much less secure than the mudguard mount (it wiggles a bit).

Busch & Muller Secuzed

This light is like the Secula, but with better seat-post mounting, the ability to mount it nicely on the mudguard, and (in both configurations) to run the wires through the mount so that they're not getting in the way or exposing the connectors much. It's brighter than the Secula. It has one major disadvantage though: the standlight time is ridiculous! After riding for a few minutes, I timed the light staying on at nearly full brightness for 30 minutes! If you like to park your bike discretely, this is not the light for you.

Busch & Muller Toplight Flat Plus

Feels like a much cheaper version of the Line Plus, but it does the job. The lighting is less bright and even (the light uses a single red LED between the two reflectors), and the standlight is more normal (requires riding for a few minutes to fully charge), but also noticeably less bright than when you're moving.

Front lights

Busch & Muller Lumotec IQ Cyo

A very nice light, the best front light I've tried. It's bright and has a good pattern that's wide enough to see into turns. I've used the 60 and 80 lux versions, and recommend going for the brightest one if you can. 60 lux is just bright enough that I feel good navigating an unlit street where I need to watch for potholes.

There are many variants of this light! The 'R' (reflector) versions have an integrated reflected on the front of the light (left, below). The "T" versions have two very bright LEDs under the main lens (on both models below). When the light is set to Auto mode, these light up during the day to help you be seen (like daytime running lights on a car). At night, they become the standlight. This is nice because they cast the light over a much wider area than the main light (which focuses on the road ahead of you), so when you're parked, it's easy to see around you (e.g. to find the latch for your shed).

Union / Marwi UN-4276 Spark 50

Beam feels a bit more square than the Cyo. This is a decently bright light with a good pattern. The standlight is noticeably weaker than the Cyo.

Spanninga Axendo 40

The 'auto' mode will keep the light on when it's quite bright outside. I like the integrated reflector. It's an affordable light that does the job. Personally, it's right at the boundary of "be seen" and "see" -- it's not quite bright enough for me to navigate potholes on an unlit street.

AXA Echo15

I've found this on some cheap Decathlon bikes. It's a good reflector that's bright enough for you to be seen on the road. Not useful for finding your way in the dark.