S-A 3-speed hubs are notorious for shifting into idle in middle gear if the chain-tension doohickey isn't adjusted correctly; i.e. the cranks spin freely with no resistance and the hub is not engaged. The GripShift neither helps nor hinders that characteristic. It has intermediate click-stops for trim (for MTB drivetrains) but when correctly adjusted, the clicks marked for L M and H do correspond to the hub's gearing. I originally had it mounted on the right, where the S-A shifter was, but of course it made the GripShift operate "backwards" and I never got used to it. To me it makes more sense on the left, even though (US convention) left usually controls the front shifting on a derailleur bike.