Biking Techniques (Part 46)

Vision

You can't ride if you can't see. This applies whether you're doing 10mph in city traffic, or 180mph on the racetrack. So prepare for rain to give you the best visibility.

There are two keys to seeing in the rain -- clearing the rain from your visor, and preventing fog on the inside.

Clearing the rain from your visor is easy: Rain-X. Apply it using the directions on the bottle, and it'll work as advertised. The faster you go, the clearer will be your visor.

Eliminating fog is harder. A Fog City Fog Shield, applied correctly, will do a fine job. (I find it works best to polish the inside of the visor with a very fine plastic polish before applying.) Some people don't like them, and in that case there are a number of alternatives. Various commercial anti-fog treatments are available of widely varying effectiveness. There's also the scuba diver's standard of rubbing saliva over the faceshield and rinsing with water -- it works just about as well as the commercial products, and is free; and you'll always have saliva at the track. Some people have had success with Rain-X on the inside of the visor, which does reduce fogging, and also beads it up and helps it roll off. In all those cases, a breath guard inside the helmet will help.

If it's really bad, there's always the car racers' standby: Attach a lump of duct tape to the bottom of the visor, so that you can jam it down and still have a ¼ inch or so of gap between it and the helmet. If it's flood conditions, rain will get in, but at least it won't fog up the visor.

From TrackDoD Novice Group Orientation