Rake or Fork Offset

The perpendicular distance from the steer/head tube axis to front axle.

Head Tube Angle

The angle between the ground plane and the steer/head tube axis.

Mechanical Trail

Trail

The distance from the contact point of the front wheel and the ground plane to the intersection of the steer/head tube axis and the ground plane. Trail is not a constant and changes as a function of steer and roll.

Steer Angle

Roll Angle

Effective Steering Angle

Tiller