- Lean as hard. As I said in Steering Through Sticky Situations : Riding in the Twisties, leaning decreases the size of the contact patch of your tire, which in turn decreases your available traction.
- Stop as quickly. You need to use your brakes with caution in the rain.
- See (or be seen by other) as well. The rain is especially problematic for a motorcyclist, because you have no windshield wipers on a bike. The rain covering your visor, goggles, or windshield can only be removed by you or the wind.
Some motorcycle gloves have chamois strips on the backs of the fingers that you can use to wipe the rain from your visor. It may be a good idea to buy such a pair.
Even though it is more challenging, riding in the rain can be relatively safe, provided you use extra caution. The most important thing to do is slow down. The combination of decreased traction and decreased visibility drastically reduces your acceptable margin of error in the rain.
Smoothness is even more important on wet pavement than on dry pavement. Jerky steering or throttle input that you wouldn’t normally notice on dry pavement can cause you to lose traction and crash in the rain. You also need to take extra care to ride in the tire tracks in the rain, because the oil embedded in the center of the lane rises to the surface during a rainstorm, especially just after the rain starts. This goop always limits traction, but just after rain begins to fall, the stuff is especially slippery. Plus, you can’t see it as well, since the pavement is covered with water.
You should always wear bright, reflective clothing when riding a motorcycle, but because of the reduced visibility during a rainstorm, brightly colored rain gear is crucial. Not only is visibility decreased during a rainstorm, but when it’s raining, other drivers are even more unlikely to be watching for motorcycles than they normally are. You need to do everything you can to help other drivers see you.
You might not notice a worn tire in dry conditions, but when the road gets wet, a bald tire becomes extra deadly. Part of the reason tires have grooves cut into them is to help move water away from under the tire’s contact patch. These grooves are too shallow on worn tires to allow the water to move, causing the tire to hydroplane - that is, to float above the surface of the water. As you might guess, a tire that hydroplanes is an extremely low-traction situation. This is one of the primary reasons you should always make certain your tires are in good condition.