There are also dynamo powered LED lights which only provide light while riding the bike, and about a minute afterwards (I assume from an internal capacitor). They are not detachable but why would that be necessary? From what I can tell they also don't require regular replacement.

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Aurornis 2 hours ago | parent | next [-]

A reliable dynamo hub setup can be very cool for the right situation, but the up front investment to rebuild your wheel around a dynamo hub is expensive. The power output is also on the low side compared to the light output you can get from the battery units.

Not having to charge anything or worry about batteries running out in the dark is a real benefit.

It's all on the very opposite end of the cost spectrum than the cheap bike light in this post though

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mopsi an hour ago | parent [-]

The old-school dynamos cost 10-20 bucks: https://axabikesecurity.com/product/axa-8201-right/

They're just generic AC motors held against the rim, as simple and cheap as it gets. Nowadays I'd add a basic voltage regulation circuitry to get a stable 5V DC out of it.

	▲	Aurornis 37 minutes ago \| parent [-]
		That's why I said "reliable" in my post. You'll spend more time futzing with one of or dealing with weather-related failures that you would have saved more time charging a pile of batteries before every ride.

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kccqzy 3 hours ago | parent | prev [-]

These are fine for bike commuters, and I’ve had them before. But they are in general not fine for recreational bicyclists; these people would gladly pay a hundred dollars for a new tire to shave off three watts and are not about to add any unnecessary human-powered accessories.

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bootlooped 2 hours ago | parent [-]

An exception is bikepackers, who may prize reliability and runtime over brightness and weight. But then the dynamo we're talking about is $200-$400 and that's not including the light.

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implements 2 hours ago | parent | next [-]

Though you can get Shimano Dynohubs pretty cheaply:

https://www.sjscycles.co.uk/hubs-front/shimano-nexus-dhc3000...

Dynohub history rabbit hole for those interested:

https://www.sheldonbrown.com/dynohubs.html

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cubefox 2 hours ago | parent | prev [-]

> An exception is bikepackers, who may prize reliability and runtime over brightness and weight. But then the dynamo we're talking about is $200-$400 and that's not including the light.

No, it's about a tenth of that, light included.

	▲	analog31 36 minutes ago \| parent \| next [-]
		Amazon has the Shimano dynohub for $125. Then you have to build a wheel. You might be able to re-use your rim if it's got 36 holes. I explored dynohubs in the past, but LEDs and LiPo batteries have really narrowed the gap. In my garage, I've got a super long USB cable that we all use for charging our lights. I've used cheap lights from AliExpress, and they are actually quite durable.
	▲	AAAAaccountAAAA 32 minutes ago \| parent \| prev [-]
		Nonsense. At $20 you'll be very hard-pressed to get even a cheap dynohub alone, and that's before the wheelbuild and the light. And bikepackers aren't going to be satisfied with ultra-low-end wheels, anyway.