I usually don't carry rain gear except for a tarp for my scooter. I generally try to avoid riding in the rain. For that reason I check/listen to the weather reports, though they are notoriously inaccurate in my area. I generally don't care if I get soaked. Pretty sure I'm going to dry, but I hate having my scooter caught in a downpour, and seeing rust on it sometime later.
I've heard people comment that it's safe to drive in the rain if precautions are taken, such as waiting thirty minutes after the rain starts so that any oils in the road are cleared off. One thing I've observed is my ability to see is really reduced, both through the visor of my helmet and on my mirrors. Cars are viewed mainly as the glare of their lights. If I see things that way, I have to wonder how do cars see me as a small, two wheeled bike on the road?
There's also the matter of traction. I've heard it suggested that you have about 80% of your traction in the rain. I think it depends on how hard its raining and the nature of the road you're on. I drive as if my traction is reduce by one half. This forces me to keep my bike up right as much as possible on the curves and to slow my speed. This will help braking as that too will be reduced.
Sometimes you can't avoid the rain, but if possible I'd suggest pulling over and waiting it out. Scooter, and M/C's are great for riding, but not when the road conditions are impaired. One good thing I've notice about driving in the rain is that other cars tend to drive slowly too, or will tend to give scooter or motorcycle riders a wide berth as they can see our own difficulty.
-Wolf
