I've got a set of Mavic A719 rims (622x19mm) and am planning to build a set of endurance wheels for my steel road bike. The bike has clearance for 28mm tires which will fit fine on those rims, but I also have a nearly new set of 25mm tires that are on the bike with its entry level wheels now. I looked at several online resources, including Sheldon Brown's site and 28mm tires are the narrowest "recommended" tires, but SB also states that the figures in the graph are "conservative" and that many riders have used tires outside of the recommended ranges without problem.
How many of you would hesitate to run a 25mm tire on a 19mm (inside) wide rim? If you don't like the idea, what are your concerns? The tires in question are Specialized All Condition Armadillo Elites (Kevlar bead) if that makes a difference.