Comment by dobladov
10 months ago
I can't state how convenient hub dynamos are, no noise, no maintenance, unlikely to be robbed without stealing the whole bike, it just works, perfect for a city bike.
10 months ago
I can't state how convenient hub dynamos are, no noise, no maintenance, unlikely to be robbed without stealing the whole bike, it just works, perfect for a city bike.
I get why people like them, but they make way less sense when you work out the capacity of an equivalent weight (not to mention cost) of lithium cells.
It's easy to get to about 90Wh, which will run a dynamo-powered light for 30 hours on max (most dynamos seem to be rated 3W).
There are definitely cases where it makes sense, and not having to keep batteries charged is nice, it's just easy to miss how good batteries are these days.
Not having to take the light off the bike and charge it and then forget to take it back to the bike, not to mention forgetting charging it and finding out when it's dark, is completely worth having a dynamo.
I live in Tokyo, and only drive in the city center. 90% of me having a light is the legal requirement of having so, I virtually never need it since the streets I usually ride are well-lit. The remainder 10% is that I like the solid feel of the bike overall and felt sad for the integrated light not to work TBH.
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In my experience engaging a dynamo is worth one switch of the gear on a 7 gear cassette. I accept the tradeoff of having to pocket the light.
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A spare battery in your saddle-pack solves most of those problems.
If you're worried about being without light, a (typical) dynamo system is more complicated and exposed than a battery system, so will be more prone to failure.
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It's not about weight, it's about having the light work when you need it.
Ensuring the battery is not empty at the time you want to ride it and it is night is not always convenient
I'm talking about commute, not sports, here.
They make a ton of sense when you’re riding long distance and when you don’t have access to a charger.
If you like hub dynamos, give hub gears a try. My electric bike has nexus 7 hub gears. It's fantastic. There's essentially no maintenance.
Exactly my setup, a nexus hub with 8 speeds, the bike has been outside under rain and occasional snow, and it's completely reliable for my daily work commute.
How are they for drag when you're not using the light?
My only misgiving is: Which bike to put it on?
> Which bike to put it on?
As mentioned, a city bike, I don't think a dynamo hub would be a practical choice for a racing bike or mountain bike, nor fit all riders.
The drag is not an issue for a bike that I use to commute to work and go shopping, the convenience out weights by far the drag, and if the worry was weight and drag there are other parts that contribute much more like the carry bags, pannier rack, mudguards that again, are convenient.
Another positive factor not mentioned would be environmental, no need to create waste with batteries.
I would imagine it's minimal. I'll never forget a demo I played with at a Science museum as a kid. A dynamo with a crank you can turn, and set of switches that allow you to turn on one, two, or three incandescent bulbs. The crank turns freely without load, and is increasingly more difficult to turn as load is added.