Originally Posted by
Andrew R Stewart
Well with campy NR ders the cable pull ratio dosen't matter, being designed around friction levers. And with the Shimano the cable pull ratio can be made slightly different depending on how far from the intended clamping point the cable is miss clamped at. Andy.
Yes, and no. Cable position doesn't matter if you don't care about indexing. But the response ratio and leverage do change when you move the cable from the far to near side. This can be an advantage or drawback depending on your objectives.
Moving to the near side, increases derailleur movement w/respect to the lever, so reduces lever travel through the range. But at the same time, it reduces leverage, so more finger force is needed.
I've often found switching the cable to the near side to help with FD action when chainring separation is higher than normal. In some cases, separating the rings, combined with near side cable routing combine to reduce outer ring rub when using the inner with the outer end of the cassette.
My rule
#17 of wrenching applies. Start by following the book, but feel free to go off book if you have a reason, or seek a specific advantage.