Just wear these under your baggy shorts. Or better yet just ride these and throw the shorts on when you get to town.
Shameless plug.. If you don't mind looking like an advert.. Follow my link and check out the closeout 09 Hammer bibs or shorts. They will run you around $30 each with discount if you've never ordered from them before. I have 4 sets of these bibs and they have been very nice. Made in the USA by Voler.