My road bikes get ridden mostly during mid-day but I've been known to go for long rides in the middle of the night. My mountain bikes get used a lot during the winter time for commuting. I can take any bike I like off the wall, put on the lights and batteries and go for a ride without worrying about lights either. I also don't have to worry about the hassle and expense of having 8 different dyno wheels and 8 different lights and the cost that would entail.

I have 4 lights, probably 8 batteries (I may have a few more), 4 chargers and less than $200 invested in the whole kit and kaboodle. Getting a single generator system for a single bike is going to cost from $200 and up which, for me, means an expenditure of at least $1600. And a $1600 outlay doesn't allow for any kind of redundancy nor for a helmet light which I find highly useful. I just don't see the logic behind that kind of outlay for something that is so limited.

And my light system can be shared. My wife doesn't ride much at night...maybe once in the last 5 years...so spending the money for a generator system for her wouldn't be cost effective. However if she does what to do a night ride, which we did this summer, I would have to shell out the money for yet another generator system since her wheels aren't the same size as any bike I have. With a battery system, all I had to do was install a clamp for my battery lights and put the batteries on her bike. We were ready to go in 5 minutes.