For anyone wondering how Head Tube angle and fork offset effect trail.
Wheel flop describes how the contact patch moves forward/sideways as the bars are turned. When you lean a bike, and the fork points straight ahead, the contact patch remains in the same spot. As you turn the bars, the contact patch moves up the wheel radius, extending the wheelbase, and moving the contact patch in the direction of the lean. Because the contact patch moves up the wheel, it also causes the front end to drop. More flop has the effect of leaning a rider into a turn, and directing the contact patch that way. It acts sort of like power steering for bicycles. Because we have the banking do that for us, we want less flop, and because we want stability while riding upright on the banking, we also want less flop. "Real" track geometry has about 14-17 mm of flop in the front end. Road geo's tend to average around 20-22mm.
You can play with HTA, Fork Offset, trail and flop here:
Bicycle Trail Calculator | yojimg.net