Sturmey Archer Dynohub 2.4 - 3.oW worth consideration?

[DukeMoto]

I've searched all over using the search here but haven't been able to locate a previous post about weather the Sturmey Archer Dynohub Drum Brakes are worth a consideration with the 2.4 to 3.oW generation.

How does this compare to a DD hubs re-gen? I'm sure DD hub size plays a role in how much re-gen it can give you.
1. Watt output.
2. Magnetic resistance \ drag in hub while coasting/peddling.

I remember how the old flip down light generators were a real drag back in the day with lights flickering all the way.

Wondering if up to 3W is even worth it when figuring in additional weight and drag. On one bike I want to put a SA drum up front anyway to improve front brake.

 

[Drunkskunk]

SA drums are great. I love mine. very stiff, spongey, and not much road feel as is true of all drum brakes, but they could stop a truck.

SA Dyno hubs, or any dyno hub, isn't worth the time. 3 watts only usable during braking would be pointless on even a 250w system. 3 watts dragging on the wheel when your riding might be draining 5 watts off the motor, and that's just a waste of power.

 

[DukeMoto]

Cool! Thanks!

I like the drums. I'll go with that. I imagine the gen also weighs a lot more than just the drum.

 

[DukeMoto]

Yep quite a bit. Where are you ordering from if you don't mind? I think I have two links stashed with them from European sites but would love to find a decent price in the US. They also look really cool 8)

I haven't decided yet who I'll be ordering from. Thanks to ebikeling sending me the wrong motor today, this project is on hold till next year.

Yeah, they do look nice. Remind me of the old chopper brakes that barley held you at a stop light on a hill back in the day on a motorcycle.

 

[Cephalotus]

Best hub dynamos reach an efficiency of about 70%+

https://fahrradzukunft.de/14/neue-nabendynamos-im-test/

They are good enough for the bike lights and maybe charging a smartphone, but they are not suitable for regenerativ braking (obviously nobody would like a dynamo hub that brakes significantly)

I have built one bike with a front dynamo hub, because I sometimes remove the rear hub motor and ride it motor less and I wanted to keep lights and electricity production for my electronic stuff.

When usinig the dynamo hub while having motor assist maybe I need 1-2W more from the battery compared to connecting the light to a DC-DC converter. I can live with that...

If you always ride the bike with motor and battery a dynamo is wasted energy, money and weight, imho.