0:00 Intro
0:47 Rechargeable Lights: Overview
1:10 Dynamo Lights: Overview
1:45 Advantages of Rechargeable Lights
2:40 Disadvantages of Rechargeable Lights
3:43 Advantages of Dynamo Lights
4:48 Disadvantages of Dynamo Lights
7:03 What's Right for You?

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LINKS

Suggested battery-powered lights for urban riding (affiliate): https://amzn.to/3mM8FYD
A bottle dynamo that isn't terrible: Bottle dynamo: https://www.bike-components.de/en/Axa...

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Bicycle lighting makes an outsized difference in your riding experience. Rechargeable and dynamo-powered lights are both good options in some cases, but what exactly are the trade-offs?

Rechargeable (battery-powered) lights are affordable and extremely convenient. They simply clip on, so they'll fit any bike with zero modifications. You can even swap them between bikes in seconds. They also offer full, instant power and usually several beam settings.

But actually keeping track of charge status can be a headache. And the fact that they need to be easily moveable means they don't have the best optics. You'll tend to get a round beam with a super bright center, rapidly dimming edges, and pretty bad glare to oncoming riders.

Dynamo-powered lights, on the other hand, run from a small generator (dynamo) inside a special front hub. This means they can run as long as the bike is rolling—and actually for a couple minutes after, thanks to a capacitor that stores a little extra electricity. And since dynamo-powered headlights are screwed in place, not moved around, they have terrific optics that resemble a squared-off floodlight (like a car headlight) when properly mounted.

But a dynamo set-up isn't cheap. It only raises the price of a new bike marginally—say, a couple hundred dollars—but it will run several hundreds as an aftermarket upgrade. It also creates a tiny bit of drag as you ride, although it's never been enough to actually bother me.

Both types will do the job.

If you ride mostly for transportation, and can find a dynamo-equipped model off the rack (within your budget), then you won't regret it! There's a reason they're basically standard on European city bikes.

But if you ride mostly for sport/fitness, or you can't justify the cost of a dynamo upgrade, then battery-powered lights are a cheap and convenient option that will serve you well.