I purchased a Shimano DH3N70 generator hub (correction: it's a DH3D71). It's a pre-built wheel from
Hiawatha Cyclery. The price was good enough that it wasn't worth seeking a hub, rim, and spokes, then building the wheel myself. I bought it Saturday afternoon, strapped it to my bike, and rode home.


The hub is replacing the battery pack shown here. My current headlight, an Inoled, works with either power source. I will not have to plug the battery in for recharging ever again. I won't have to forget it ever again. The battery pack blocked access to my bottle cage too. No more of that.

Here's a photo of the wheel installed, but no wires are in place yet.

This shows the holes for the wires. At first, I was a little bit lost as to how the get the wires in there.

I found a
PDF of the instructions for hooking up the light in a Google search. This looks like a lost Lego part, doesn't it? To remove it from the hub, you just pull it off. It only took a little strength.

It's a two-piece affair. I popped the two pieces apart by pressing a tiny screw driver into a slot on the back of this piece (the slot is not shown in the photo) and prying them apart with my fingernails.
Separated at last.

Then I fed the stripped wire ends into the holes and bent them over into the little channels shown here. At the point this photo was taken, I had only bent over one of the wires. After bending the wires, I snapped the black cap back onto it and plugged it into the fitting on the hub.

I rode it around in the daylight. From what I've read, some people claim that they notice the increased drag. Others say there is no noticeable difference. I couldn't tell during my quickie test ride.
I'll compare its brightness to that of the battery pack tomorrow morning. It'll be an easy comparison, because I can change the power source from the hub to the battery by plugging in the other wire.
Just for fun, I recorded a video showing the drag created by the generator hub. I compare it informally to a conventional hub. I'm not worried about the drag, but I thought it would be nice to show it, because the topic always comes up in conversations about generator hubs.