Motorcycle Panic Braking
Although motorcycles have sufficient braking power and traction to enable them to stop in as short a distance as a typical car, panic-braking a motorcycle poses unique hazards and requires greater operator skill than stopping a car in panic situations or in a skid.
The vast majority of motorcycles use an independent system for the front and rear wheels, with a lever on the right handlebar controlling the front brake and foot pedal controlling the rear brake. A small number of motorcycles link the controls and an even smaller number have a handlebar lever to control the rear brake. We know of no current research that indicates which if any of these is more effective.
Braking seems to be one of the most difficult skills for a motorcyclist to master. It is also one of the most critical. It is difficult because most motorcycles have two separate brake-control systems, one for the front wheel and one for the rear wheel. As the front brake is applied, weight transfers to the front tire, which causes available traction to vary as weight shifts, requiring the rider to adjust pressure on each brake control in a maximum-performance stop. As found in the Hurt Report, in a situation the motorcyclist typically overbrakes the rear and underbrakes the front, even though weight transfer means the front brake must do the majority of the braking.
Overbraking can either cause loss of steering control or total loss of control. If the rear wheel is locked, the rider typically loses directional control. If the front wheel locks, the rider is likely to crash due to loss of stability.
Rider training courses, available for the last two decades, have sought to develop improved motorcyclist braking skills. Greater emphasis has been focused on proper braking technique and the importance of the front brake.
There seems to be a greater recognition of the importance of front brake use than there was 20 years ago when the Hurt Report was conducted. Failure to brake effectively and loss of control during panic-braking continue to play a role in motorcycle crashes.
Continued rider training and practice are key elements in assuring maximum rider performance in a panic situation. This allows riders to learn brake control during a maximum-braking stop, internalize the process of a hard stop so they react automatically in a panic situation, and deal with events such as rear-wheel lock-up. However, even panic-braking practice involves risk, because locking the front wheel can cause an immediate loss of control and a fall. This makes it difficult for rider training organizations to train riders to use the front brake to its full capability.
Motorcycle braking systems have steadily improved in terms of power, control, and reliability and continue to do so. Virtually all street motorcycles now have hydraulically actuated disc brakes, at least on the front wheel.
Most motorcycles use this type of brake—which is self-adjusting for wear and more resistant to fade and wet conditions than drum-type brakes—on the rear wheel as well.
Many street motorcycles also have powerful dual disc brakes on the front wheel, which provide more stopping power where it is needed most.
This is particularly true for sportbikes and touring motorcycles. Cruisers, despite weights that are normally heavier than other styles except touring motorcycles, often have just a single disc brake in front, although this seems to be changing.
Two technical developments have sought to simplify braking control and provide more effective braking. Linked braking slows both wheels with a single control. Antilock braking systems (ABS) allow the rider to apply maximum braking force without fear of wheel lock-up and the resulting loss of control, providing the bike is not leaned over. Under many pavement conditions, antilock brake systems allow the rider to stop a motorcycle more rapidly while maintaining steering control even during situations of extreme, panic braking.
Although incidental and first-hand experience indicates either of these systems can be effective in countering the problems faced by a motor-cyclist in a panic stop, we know of no research that shows how they perform in the field compared with similar bikes fitted with standard brake systems. The added costs (particularly for ABS) and reluctance to accept them by some experienced motorcyclists have limited the adoption of these potentially effective systems.