Just like the Wada scale for measuring hill climb difficulty, there could be a standard scale for how long its takes for feet to be totally soaking wet when riding in "normal" rain and with water standing in places on the roadway.
- With normal cycling shoes and socks -- less than 10 minutes = 1x.
- Add rubberized shoe covers -- another 10 minutes maybe. 1x improvement.
- Protect the bottom of your shoes so that water does not come up through the cleat holes, maybe you will last 30 minutes or more. Another 1x improvement.
- Add fenders and you might get 5-10 minutes longer. Maybe .75x improvement, plus a cleaner bicycle, especially on the back of the seat tube.
- Add an inside shoe lining of a waterproof goretex sock or plastic bag, and you might last up to an hour in total (and will ensure that when you do get wet, your feet will be swimming in a warm, soupy mess even long after the rain stops). A 1.5x improvement.
- Wear a Gore Tex "touring" bike shoe such as my Shimano MT71 pair, and add another 15 minutes or more, and no swimming feet. A 1.5x improvement.
- Wear rain pants that cover the top of your shoes and socks, combined with the shoe lining or water-resistent "touring" shoe. Another improvement, but even the best rain pants are too warm/sweaty for riding at a reasonably high pace and you end up just as wet inside as out if you go any distance at high speed, or do climbs of more than 10-15 minutes length.
All of these are incremental measures. Nothing keeps you really dry for very long.
In this framework of incremental measures, last year I read with interest a note from Seattle-based randonneur Jan Heine (publisher of Bicycle Quarterly and author of The Golden Age of Handmade Bicycles, among other books) in which he extolled the virtues of a large, low to the ground mudflap on the front fender. You can read it here. And a comparison with a no-mudflap ride here. I made a mental note to try to add a decent front mudflap. It looks like yet another major incremental improvement. An old technology, that works.
I finally got a large leather mudflap at a nearby bike shop last week, and attached it (temporarily at least, with string) to my Curana Lite front fender for a rainy day commute.
I rode in to the office Wednesday morning -- 30 minutes, with light rain and some water on the street, wearing the Shimano MT71 shoes. Completely dry. I rode home with the rain stopped but roads still wet -- completely dry. And of course, the mud flap seems to have picked up a lot of crud, but my bottom bracket, shoes and lower legs were clean instead of the usual, post-rain cover of grime.
Stay tuned for updates.