Originally Posted by
Kimmo
Actually, come to think of it, they could increase that radius without increasing effort (if you increase cable pull, you're increasing the amount of cable friction felt, but nothing more, since you're still moving the RD the same distance), by reducing the lever throw so the cable pull is the same.
when you decrease the cable pull, there’s less room for error(cable stretch/housing shrinkage).
JMO, but frequent replacement of very inexpensive part, is a fair trade off for smooth and light effort shifting. I suspect that is why Shimano hasn’t redesigned the shifter.