Originally Posted by
nlerner
I really see compact doubles as far more useful than a triple, particularly with a long cage RD so that your small front and large rear cogs are about the same number of teeth. And no need to find a longer BB spindle and a FD that can handle the three rings. I actually just removed a triple from one of the few bikes in my fleet that had one, and I was surprised to see it was a triple because it’s been years since I’ve had a need to shift into that small ring!
With an indexed system, you have to shift the double so much more to cover the same range as 2 shifts of the triple FD. That's the main reason I ride triples.