Originally Posted by
Drew Eckhardt
It depends on how hard you'll be riding, how hard it will be raining, and how cold it is out.
Where the answers are closer to riding hard, light rain, and not cold don't wear cotton, just ride, and put on dry clothes + shoes when you get where you're going. If you wear rain clothes you'll be hot and very wet from your sweat; if you don't you'll be between a little cool and comfortable, just damp except for a few wet spots, and a lot more comfortable.
Where the answers tend towards an easy spin, raining hard, and too cold a cycling rain jacket (with a long back flap and zips for ventilation), cycling rain pants (tight at the ankles), helmet cover, shoe covers, and gloves are nice.
I usually ride my 12 mile morning commute at a 140-150 bpm heart rate which is about as hard as I can go without being slower in the evening or next day. It was raining lightly this morning. The temperature was 55 degrees. So I wore a short sleeve jersey and cycling shorts. I need new cycling socks though - the cotton ones were like dirty wet sponges by the time I got to my office.
I think it's more like:
hard riding, hard rain, not too cold (which is given since rain freezes when it's too cold)
vs
easy spin, light rain, too cold
No amount of "rain wear" will keep you dry if you jump in a swimming pool. It only works for light rain and light riding, which is why I recommend going straight to the ultimate solution: clothes that don't sponge up water. Cycling specific clothes aren't very good in this regard because they have too much lycra which seems to cause wicking/sponging and they're also usually short sleeved/legged. You really need 95% hydrophobic fiber content or more and even at that it can't be too thick or the water will get trapped in the "fluff". That means 95%+ fabric content of polyester, polypro, and/or wool with long sleeves and pants and the only garments I have found like this are marketed as ski thermals (and the only ones appropriate for outer clothing are duofold...other brands have crotch flys).
If you start out warm/comfortable then first 5 miles should be comfortable, next 5 miles should be cold as your skin gets colder and your body core is still warming up, and after 10+ miles the furnace is stoked you'll be comfortable for any temperature which can support liquid rain. Then when you get back indoors your body heat will evaporate any sweat/water left on your skin and clothing within 30 min.
That's my experience at least.