Each spoke talks to the other through an IR sensor. Sometimes mine would come on in the middle of class. We think the tv or VCR remote was triggering them.
I took mine off this year because I had one that would not stay lit - even with brand new batteries. They don't look as good with only 2 and getting them on with their with the weight evenly distributed can be a pain.
Eventually we'll look at the one that is not working right and see if we can figure out what's going on. They are kind of filmsy and I do put on a lot of miles. They may not be up to the long haul. I know they made me more visible. People would stop what they were doing and watch me go by. Kids also said something.
V.