Hub Dynamo Vs Bottle

Cycling at 10 20km h works out to be around 50 60.

Hub dynamo vs bottle. A hub dynamo is a small electrical generator built into the hub of a bicycle wheel that is usually used to power lights often the hub dynamo is not actually a dynamo which creates dc but a low power magneto that creates ac most modern hub dynamos are regulated to 3 watts at 6 volts although some will drive up to 6 watts at 12 volts. Old fashioned bottle dynamo and rear light with normal bulb dynamos aka generators are really looked down on by almost all americans and many brits as well. Given that touring and bikepacking is often conducted at speeds below 25kph 15mph the most powerful option 3w is necessary for charging usb devices and it s the best for low speed lighting too. There are three different power specifications for dynamo hubs.

Alexandra madison jul 3 11 at 0 17. To the uninitiated a dynamo sounds unappealing because it slows you down makes alot of noise slips in the wet wears out your tires and the lights aren t very bright and they go out. The charts above show the power created at the dynamo hub by different usb chargers. 2 4 w is allocated for the front light and 0 6 w for the rear.

Apparently it would also work with the hub dynamo from your experience it appears that the hub is a better option by a margin. Dynamo hubs are quite widely adopted in the bicycle touring bikepacking and ultra racing scenes. Modern led lights will draw more power than this about 7w from a hub dynamo at 30kph. This means that when the charger is making between 1 3 watts you can roughly double that figure to work out the drag in watts at the hub.

So for a 3w bulb light a bottle will make you put in an extra 7 5w of pedalling power and a hub will cost an extra 5w. Lights off drag from a good hub is about 0 5w at 20kph 1w at. A good hub dynamo is 60 efficient. The efficiency of a high quality dynamo hub at low power eg.

Just a few models of hub dynamo produce 6 v 2 4 w making them suitable for powering just the front light. Very nearly all currently available dynamos whether hub or bottle have the same output of 6 volts at 3 watts to power both front and back lights. With led light technology allowing for 1300 lumens or 100 lux light outputs usb charging for gadgets and lithium ion battery storage dynamo hubs feel like the right way to harvest energy. A decent bottle dynamo is 40 efficient.