I'm new to cross racing this year. I've done three races so far and have at least one more to go. The weather and conditions were completly different for each race. Yesterday's race was on gound that had over 1" of rain on Saturday and a coating of wet snow on Sunday. During the race the ground got more and more sloopy and riding some sections of grass was like riding in peanut butter. During warmups I felt my rims bottoming out when going over sunken timbers so I aired the tires at 60 lbs for the race. When watching the A race later on I noticed that many of the riders had a lot less air in their tires, I could see the flex in the tire as they crossed a sidewalk near the finish line. I'm thinking I rode with too much pressure. I did have some slipping when going up steep hills but it was very wet also.
I weigh 190 and my Trek's tires are 32cm width. What is a good rule of thumb regarding tire pressure during racing and under various conditions?