Best hub motor for bike generator?

[titusmc]

Well, it's dark and cold in NY again and I'm barely riding my road bike. I normally ride a trainer in the winter to stay somewhat fit, but this year I'm thinking about putting a rear hub motor on my trainer bike and pedaling against regen for my workout (still mounted on a trainer). I fully understand it's not a practical means of power generation, but I still think it would be a fun thing to build and it would be cool to ride my ebike to work with energy from a previous workout (or several).

The main question is - what is the ideal hub motor for such an application? I know direct drive is a must, but would fast or slow wind be better, etc?

I'm thinking I wouldn't even need a wheel - just a bare hub motor should work, right? I already have some spare grin controllers and a CA3 lying around...

Please move elsewhere if this doesn't belong here.

 

[titusmc]

Think I may have just answered one of my own questions - a slow wind would be desirable because lower cadence will produce higher voltage, I think.

 

[dogman dan]

Not sure the wind really matters, since you can simply adjust the gear you are in.

The guy making pedal generators I know of was just using a 9x7. I'd say just get the cheapest dd kit on amazon for that use.

 

[MadRhino]

A fast DD motor is best. Slow and fast windings will produce the same voltage, but the fast one will produce more watts per RPM.

The controller is what will make the most difference. Best is to buy a programable controller, and build a setup with variable regen. Then you will have control on how hard to pedal it will be, by adjustment of power produced.

 

[dogman dan]

Those motors in the 1000w kits are usually a 10x6, so the slightly faster version. No need to pay big bucks for a higher quality motor, or different wind.

Controller not absolutely needed, but you will get one that likely can be made to have regen, in the cheapo kit.

Might be worth doing the whole wheel, you get one in the kit. I've wondered if a water filled tube might help, give the stationary bike a flywheel effect.

 

[titusmc]

I ended up getting this: https://amzn.com/B01GR9026O

It should be here tomorrow to play with (I love Amazon Prime). I also think that a water-filled tube may be a good idea for the flywheel effect, but we'll see on that. Ideally, I'd run this on my road bike (Trek 2200), so the 26" wheel may have to go... Alternatively I could run it on an older mountain bike, but if I'm going to actually use it much I want the road geometry.

 

[dogman dan]

Should fit the road frame, without tire. Or even possibly with a small tire.