Is there any way to adjust the drag on modern Shimano friction shifters? I have two identical sets of Shimano 8-speed bar end shifters (friction/index front and friction rear) and an older similar set of S.T. Barcons, and one particular Shimano front shifter requires way more torque than the ones on the other bikes. It`s the newest set, but still ought to be plenty broken in by now, I would think. I tried losening the mount screw just in case and that didn`t do anything but make for a wiggly lever. Maybe some method of strategic lubing that will free it up, but still not let the derailler spring win the tug o war? Shims someplace? It sure would be nice if that particular shifter were as easy to pull as the others. BTW, the cable and housing are almost new.