Countersteering

If the mass is not first leaned into the turn, the inertia of the rider and bike will cause them to continue in a straight line as the tires track out from under them along the curve.

Countersteering at low speed may be further concealed by the ensuing much larger steering angle possible in the direction of the turn.

[citation needed] One effect of turning the front wheel is a roll moment caused by gyroscopic precession.

The magnitude of this moment is proportional to the moment of inertia of the front wheel, its spin rate (forward motion), the rate that the rider turns the front wheel by applying a torque to the handlebars, and the cosine of the angle between the steering axis and the vertical.

In comparison, the lateral force on the front tire as it tracks out from under the motorcycle reaches a maximum of 50 N. This, acting on the 0.6 m (2 ft) height of the center of mass, generates a roll moment of 30 Nm.

[10] While the moment from gyroscopic forces is only 12% of this, it can play a significant part because it begins to act as soon as the rider applies the torque, instead of building up more slowly as the wheel out-tracks.

[3]: 15 At higher speeds the self-balancing property of the bike gets stiffer, and a given input force applied to the handlebars produces smaller changes in lean angle.

When the need for a quick swerve to one side suddenly arises in an emergency, it is essential to know, through prior practice, that countersteering is the most efficient way to change the motorcycle's course.

[17] According to the Hurt Report, most motorcycle riders in the United States would over-brake and skid the rear wheel and under-brake the front when trying hard to avoid a collision.

[18] The often small amount of initial countersteering input required to get the bike to lean, which may be as little as 0.125 seconds, keeps many riders unaware of the concept.

[22] A prototype tilting multi-track free leaning vehicle was developed in 1984 that employs automatic countersteering and does not require any balancing skills.

[8][24][25][26] Documented physical experimentation shows that on heavy bikes (many motorcycles) shifting body weight is less effective at initiating leans.

No-hands riders may be able to keep a heavy bike centered in a lane and negotiate shallow highway turns, but not much else.

[24] Although on a sufficiently light bike (especially a bicycle), the rider can initiate a lean and turn by shifting body weight,[8] there is no evidence that complex maneuvers can be performed by bodyweight alone.

[10] Motorcycle speedway racing takes place on an oval track with a loose surface of dirt, cinders or shale.

Graphs showing the lean and steer angle response of an otherwise uncontrolled simplified model of a typical bike, traveling at a forward speed in its stable range (in this case 6 m/s), to a positive steer torque (to the right) that begins as an impulse and then remains constant. It causes an initial steer angle to the right, a lean to the left, and eventually a steady-state lean to the left, steer angle to the left, and thus a turn to the left.