Originally Posted by orange leader

about 90% of my flats also occur during or shortly after a rain. There are several hypothesis' about why this is.

First, try picking up a small piece of glass or wire with the tip of one finger (careful don't get cut). It will probably just fall off. Then try it again after moistening your fingertip. The small object will pick right up. I think this gives many sharp objects multiple chances of puncturing your tire.

Also, glass (or wire, etc) will slice much more easily through rubber while either is wet than they would when dry.

So....since your mtn bike is your wet weather ride, you are destined to get more flats on it, than on your road bike. I don't think it has much to do with expense here, or width of tires.