I've been riding mountain bikes at night, off and on, since I was a teen. It's fun. It's scary. It's social. When I was a kid, there was a regular Thursday Night Ride from the Depot in Mill Valley, California. We'd all roll up the mountain, then take various ways down. The hot setup, for me was two Mini-Mag flashlights, each with two AA batteries, in DKG (Dave Garoutte) handlebar mounts, one slightly up, one slightly down. There were many nights I finished without lights.When my kids were old enough that I could eat dinner with them, do baths, read...