The Gyroscopic effect is just a small part of it.<quoted text>Gyroscopic action.
Same as with a moving bicycle.
A simple explanation does not seem possible because the lean and steer are coupled by a combination of several effects including gyroscopic precession, lateral ground-reaction forces at the front wheel ground contact point trailing behind the steering axis, the wheels being so narrow, gravity and inertial reactions from the front assembly having center-of-mass off of the steer axis, and from effects associated with the moment of inertia matrix of the front assembly. One also has to take in/consider centrifugal force and the castor effect.
Tick I would suggest you read up some before you respond to this.