Originally Posted by
noglider
I see a lot of people here carry a spare headlight in case the main headlight fails. Not a scientific poll, but who here does not do this, and why?
My main commuter bike has a dynamo powered headlight, and it pretty much never fails. It has a dynamo powered tail light, and I also use a battery powered tail light, and I ALSO use a battery powered spoke light, so I have quite a bit of redundancy in tail lights.
"Pretty much never" isn't never.
I had a dynamo light failure when I neglected to disconnect the cable removing the wheel to free a piece of plant that was rubbing annoyingly on the light and the terminal pulled off. 60 miles from home that would be really bad.
So I have a B&M Ixon IQ Premium with a set of NiMh AA batteries installed but can run off alkaline batteries from any 24 hour grocery/convenience store.