Hey there.. I have the same problem on Softail. Vance & Hines pipes and I've burned through 4 pairs of slacks and 1 Winter Riding Suit. I can't afford that. I found this product called the "Crotch Cooler" http://bit.ly/r5ULvY .. I'm very happy with it, and were I able to leather work I'd have made my own.
When I received it, the first thing i notice was the thickness of the hyde. Very thick, and it's several layers as well.
Just exactly what you were talking about.
I hope this helps..