I would stay away from the Castelli Free Aero Race 4 bib shorts [link is to Competitive Cyclist, as I couldn’t find this version on the Castelli website] - last year’s version. I’ve been a Castelli bib shorts for years, and really like the previous version, but whatever material Castelli went to for the straps just isn’t robust enough. I bought multiple pairs of these when I could get them on sale, and this material has ripped on at least three pairs - so not a one-off problem.
I’m hoping that the new “version” - Free Aero RC Pro Bibshort - fixes this problem. From the pictures on the Castelli website, it looks like they redesigned the straps, so I’m betting that I’m not the only one who experienced this ripping problem.