Originally Posted by Al.canoe
I understood HillRider. I was making a general point about component ratings. Through experimentation I have found that I can often exceed ratings with satisfying results. I should have said that before giving the example that I did.
Gotcha. You're probably right about this - modern front deraillers may well do okay with less than 10t difference between chainrings. But they won't work with small differences (4-5t) between chainrings, simply due to the physical design.