Originally Posted by
prathmann
Good reason to have a second rear light and also a rear reflector. Note that using a dyno as the power source only eliminates one source of failure (the battery) and adds some wiring as an additional one. Still a good idea to have some redundancy since there are quite a few ways in which lights can fail.
This is an important comment. especially in the winter. In the low 20f temps batteries have greatly reduced run times. Important if you're on a long ride. Always have a back up light, front and rear. A good reflector can be extremely bright when hit by car headlights. I always have both. I do centuries in the winter, if the road is dry and no conditions that might make ice.