The amount of travel needed depends on the CG and speed range that you experience. On my RV-8, full nose up trim on final approach is not enough to zero the stick forces, and it looks like I'll need most of the available nose down trim at high speed at aft CG......you'll never use more than a fraction of it. We seldom see much more movement than the thickness of the trailing edge of the tab....3/8" or so.
The amount of travel needed depends the CG and speed range that you experience. On my RV-8, full nose up trim on final approach is not enough to zero the stick forces, and it looks like I'll need most of the available nose down trim at high speed at aft CG.