wheels are expensive, no doubt. But they last a long time and a hub dyno means you never have to worry about charging batteries. I find that really annoying. And you also have to figure out where to put the batteries, which is also annoying.

I am an engineer with good fabrication skills, and I just find making lights not to be worth it. If I make a robot and it has a failure, big deal. If I'm out riding and my light goes out, that is a big deal. I have had this happen because the glue I used for an emitter failed. Thought I was going to have to walk 7 miles.

I agree with Tom, I would probably use a bottle dyno. They are a little loud, but I've never had any problems with one even in freezing rain