I have to dress more or less professionally at work, and it's never been a problem. I just loosely roll up the work clothes, put them in waterproof panniers, ride to work as fast as I can, and change shortly before work starts. I bring deodorant and a small towel with me, and, so far, no one seems to notice that I'm any different than the people who drove there. In the winter, I wear my work pants, and just change shirts when I get there, but I don't recommend this, because of chain oil making marks on the pants. (I do it anyway, I'm not sure why, probably because I assume my continued employment depends on my job performance more than it does on my wardrobe.)