Bibs usually have sort of a high back, so in order to pull the pants down you have to remove your jersey. Since my jersey pockets are usually full (tube, food, key, ziploc-baggies etc etc) this is a real pain in the butt!

If you ride long enough and far enough you eventually get over the fear-of-peeing -in-public thing. Mother nature takes over.
Then there are the times where I have to choose between nasty smelly port-o-let and a tree? Guess which I'll chose
every time???