I'm building a 3x9 speed touring bike with 50-38-24 chainrings. The people in the touring forums recommend the 9 speed Tiagra front derailleur, because it has a comparatively wide cage that minimized chain rub.
My setup has a 26 tooth difference between the highest and lowest chainrings. Shimano's tech docs say that the Tiagra front derailleur has a 20 tooth capacity. Will it still work, and if not, what is a better front derailleur?