How to ride on a wet road?
Keep your brakes dry by regularly braking a little bit. Wet rim brakes need some time to get grip. With disc brakes, that’s hardly any problem.
The difference between straight riding and cornering is much bigger than when the road is dry. On straight pieces you can ride as fast as when it is dry. That is scary to some, but it is possible. You need to calculate a much longer brake path for a corner. In a descent this is even more the case.
The bends are a bit slower than in dry weather. You keep your outer leg longer low and start paddling again later and you go out of the saddle later.
Sometimes you don’t ride a corner in one pretty round line, but divide the corner in pieces that go more or less straight (where wet) and rounder (where it is drier).
Take note of the white paint stripes, including the slightly increased stuff, pit covers, train rails and the like. Go over there with a 90 degree angle as far as possible and do not brake there especially.
In general: Take a greater safety margin than you take under dry conditions.
Wetness is in gradations, whether or not combined with dirt and oil and the like. In addition, it may be different every few meters. As a result, you learn much less what is possible and is not. So on a wet road, you can tune yourself less than on a dry road. In dry conditions, one asphalt is more or less the same as the other. With many hours of riding and slowly increasing the limit, you can learn to get close to the maximum possible speed (in the corners). Under wet conditions, sliding risk may vary considerably. Certainly if it’s a little bit wet there, and somewhere else dry again.
If you drive the same route more often like in a criterion, you can better adjust to the corners. If you get a corner only once, that is not possible.
In wet conditions, therefore, you must ride further under the maximum possible in such conditions than in dry conditions.