I had a conversation with a coworker recently about shorts. Specifically, she never wears bibs and I wear nothing but. She asked me why I prefer bib shorts. And I realized that I have a few reasons, but a major one is that it's what cyclists do. There's a little communal snobbery over bib shorts as opposed to regular shorts; those in the know are aware that bib shorts are better. So it's at least partly a tribal identifier to show that you're an in the know cyclist (similar thing goes for skinsuits in crit/TT/CX racing).
There are some non-snobbery reasons to wear bib shorts, too. The chamois tends to stay put better, especially if you have narrow hips. I don't have narrow hips, but I do have a narrow waist. In my case, wearing bibs instead of shorts removes the elastic waistband that never seems to hit me in the right spot. When I wear normal shorts, I find that my hip flexors start to get sore and my low back gets achy, I think from the pressure of the waistband. And I feel like my breathing is restricted if I try to relax and breathe into my belly. Getting back to the shorts staying in place, a moving chamois is a chafing chamois, so bibs help reduce chafing by reducing movement of the shorts against your tender bits.
Bibs also eliminate the potential for a dumb-ass burn/tan. You know the dumb-ass tan, a.k.a. triathlete tramp stamp; it's the strip of skin between a short jersey and low-cut shorts that gets burned or really darkly tans because who would ever think to apply sunscreen there? Probably less common now that triathletes wear more skinsuit type things, but I remember seeing it on everyone at Wildflower in 2008. Bibs come much higher up the back, high enough that no jersey is going to be fulled up that far, unless you accidentally tucked your jersey into the back of your shorts when using a port-a-john. Also important for modesty--no plumber's crack showing to those behind you!
So that's why you should choose bibs over regular shorts. You'll notice that they're usually more expensive, but now you have some reasons why they're worth it. Next time, I'll talk a little about why you should spend more on shorts in general, and I'll begin a series of kit reviews based on my own experience.
If you have a favorite pair of shorts that you'd like to review, or if you bought a pricey pair and regretted it later, I'd love to feature your experience. Get in touch if you'd like to help me out with my series of kit reviews! I'm particularly interested in hearing from other women on their experiences, since it seems there are always many more resources of that type for male cyclists than us ladies.