BCRider

Yeah, I suppose they will but only if there's some problems in the brakes like rim walls getting worn to a rounded ditch shape or high/low spots or kinks in the rims or rims in need of cleaning. I've had that happen with my rim brakes and you're right, if there is any shortcomings the Speed Dials being moved in will show them up that much more.

But on a well set up clean and good condition rim brake moving the shuttles in a little will work just fine.

Silver_ghost, if you pull the levers and then move the dials you'll see how it moves the cable end shuttle into or away from the pivot. Away means more cable pull but you need more lever pressure to get the same braking. Moving them in towards the pivot means less cable pull but a higher mechanical leverage for you so the lever pressure needed for the same stopping power reduces. Great for fine tuning for one finger braking. Just don't try to use them in the full in position with linear (as in V) brakes. If you do then you'll find that it really makes them grabby and inconsistent. But with some care you can move the shuttles in a few turns and gain some advantages.

These levers are also the hot setup for mechanical disc brakes IMHO. It really helps for adding power to the setup. And since with mechanical disc brakes there's no rubber parts to squish you can move the shuttles pretty much through the whole range to get the feel and performance you want.