Originally Posted by
randya
...reflectors on pedals and cranks are in motion when you are pedaling and work as well as a rear blinkie for visibility to following motorists at night, without batteries; test it sometime on the road with car headlights and you will see.
I would not go out riding at night w/o rear blinkies, no matter how many reflective devices I was sporting. It's not legal, and not smart. I don't know if you actually meant to advocate reflectors in place of lights, but I would argue that lights are always needed. The lights can be seen from much further away, and do not depend on a secondary light source (like someone else's headlights, which could be pointed a different way, dim, unlit...).