Much depends on how low you can set your front derailleur and on the tooth drop for which it was designed. Newer road cages are generally optimized for 53-39, but most will work quite nicely with 50-36, and if you can lower the mechanism far enough, 48-34. A 16-tooth or larger drop may cause rough shifting, chain drop, chain snag, and other nasty issues, unless one shifts very carefully at all times. (I have run 48-40-24 on my mountain bike in years past, and a successful 24-to-40 upshift does require "judgment, brains, and maturity.")