Originally Posted by
Tourist in MSN
When you say "modern dynamo", they have not changed much in over a decade.
This article is one of many I read before I built up my first dynohub wheel over a decade ago. There is a graph with drag with lights on and off.
https://www.cyclinguk.org/sites/defa...ub-dynamos.pdf
I can't feel any drag when I am riding with lights on, so I usually just leave them on in daytime unless I am charging up batteries instead.
I mainly bought my first dynohub for bike touring to use for battery charging. On my last two tours, I was fully self sufficient on electric power from my hub. But my phone is typically off. I am very careful on my GPS to keep the backlight off or at a minimum. When charging batteries, my lights are off. I often use a AAA powered flasher in the rear during daytime.
If I am off the bike, lift my front wheel and give it a spin by hand, it will slow down much quicker if the light is on compared to off, so I know there is drag, but it is quite minor. That said, if you are a racer, you might not get on the podium if you had your lights on.
You did not say why you are interested in a dynohub. If it is for lighting, they are great. A very good recent article on that is here:
https://bikepacking.com/plan/dynamo-...harging-guide/
If you are interested, I described how I wired up my rando bike here:
Wiring up a dyno powered lighting system with USB charger
For battery charging, I used to use the Sinewave Revolution, but I switched last year to the Cycle2Charge V3 USB charger, it puts out a bit more power, but a downside is that if stops putting out any power below about 6.5 or 7 mph.
Thank you for very useful information.
I’m not a racer so no issues about the podium. Finishing what I plan for a specific day is good enough.
By modern, I meant whatever is currently considered the best. If this technology is a decade old, that only means that the mechanism is already near perfect or someone would have surely improved it. Of course, in the context of bicycles, progress and time have a different kind of relationship… it’s not like electronics, batteries, LEDs.
I will definitely have a couple of battery operated blinking lights for front and rear in addition to the main light running off the generator. I will look into the most efficient LED emitter to mate with dynamo. I am hoping that the light part of the setup has been updated during the last decade. If not, older LEDs were not as efficient as the newer versions. If needed, I would swap the emitter and the driver. We shall see… another winter project, they keep adding up.
Once again, thank you.