Left rudder never needs more than a feather-light dab, and right rudder needs constant pressure with a hefty shove if I want to actually bank in that direction. I understand that the propellor slipstream introduces some bias, but do you think that's normal for a C172 at moderate power settings?
Correct - The propellor will generate a slipstream that provides constant airflow on the left side of the tail, causing the nose to want to swing to the left, and the tail out to the right. To counteract this, you need right rudder. The higher the RPM (I.e. when your in a climb or want to go around etc) the more right rudder you need to keep the aircraft in balance. You will also notice this the other way round - if you chop the power for a descent, then the nose will swing gently to the right, and inertia causes it to go too far if you like, so here we need left rudder. It can be quite difficult on the ground when starting the takeoff run, especially in Cessna's as the rudder works on a spring and is not directly linked like it is in Pipers.
One more thing - next time you are doing the walk-around, stand in front of the spinner and notice how the engine is 'off-set'. This means that the engine is mounted in such a way as it points to the right (looking from the cockpit). This is again to counteract the 'pull' to the left when you are flying!
Hope that helps - and remember, have a look at the slip indicator (Turn Coordinator) - ball to the right means right rudder needed and so on.....
Lee
