How did you evaluate this? When you turn the axle with your hand, it feels terrible. When you suspend the bike and spin the wheel, it seems only slightly draggy. When you ride the bike with over 100 lbs of inertia, the drag is imperceptible.

As another alternative does anyone have experience running these modern dynamo light systems on dc batteries? I'm looking at the iq cyo premium and toplight line-plus.

That question came up recently. Someone pointed out why it might not work, but I'll be darned if I can remember the explanation.

My understanding is that dynamo hubs actually generate a/c, so you can't run them directly off of dc current.

Sometimes they make a dc current model for electric bikes.

But there's no real reason to do that as nowadays they also sell battery versions. The Ixon Iq Space is B&M's version:
https://www.bikeforums.net/commuting...l#post19820037

The Lupine SL A4 is a brighter light with a cutoff and an external battery pack:
https://www.bikeforums.net/19855873-post12.html

There are brighter bicycle headlights for DC available than for AC.
Like B&M IQ-X E (150lx), Supernova M99 series (150-380lx) and Lupine SL (150lx).

[Quoting the company websites] DC lights now, are for electric bikes ... they wire to the battery that makes the motor power the bike..

& No On/Off switch on the bottle dynamo versions of Lights




:innocent:





....

DC lights are usable on every DC power source with the right voltage. So besides pedelecs there are also battery packs as an option.

Internet gotcha? DC is DC [Edison promoted DC, Tesla was working with AC]

I made one 30 years ago for halogen headlight bulbs. & incandescent tail light 5 D Ni Cad rechargeable batteries (1.2v x 5 =6v)

.. but nobody in marketing was selling that as a feature..

Good luck with your creative solutions.


:innocent:

Back to the original question, difference between bottle and hub lights ...

Usually the lights that are made for bottle dynamos do not have a switch because you can disconnect them from the wheel to turn them off. I picked up a couple several years ago on a clearance sale, I used them on a hub but with no switch I just left them on. I later bought a lamp with USB charger, thus no longer use teh old bottle lamps.

If you might buy a hub later, you might want to get the lamp now that has a switch to use with the hub later. But, since I can't feel any drag from my hub, I often just leave the lights on since it will not hurt anything.

Or, since the lamps get better and brighter every year, buy a cheap one now and a better one later if you buy a hub later.