While all of this is possible using wheel sensors and an ECU to interpret the information properly, some manufacturers take their traction control a step farther. Ducati’s DTC relies on a separate ECU with an accelerometer that measures lean angle and acceleration. Aprilia and BMW bikes have multiple accelerometers and gyroscopes to give a more complete picture of what the bike is doing. The advantages of which can provide additional electronic assistance such as launch control and wheelie control. Most aftermarket traction control modifications and manufacturers like MV Agusta do not use wheel speed sensors to detect rear wheel slip. Instead the ECU checks rpm spikes against a set of known values based on engine speed, throttle, and gear position to determine rear wheel slip to provide a corrective measure.
Imagine riding along your favorite mountain road and midway through a corner you give it a bit too much gas. Your finite level of traction for the rear wheel is used up and the real wheel is about to start sliding. Without traction control, several possibilities present themselves. If you maintain or increase throttle, you’ll probably exacerbate the loss of traction and continue to slide. If you chop the throttle, the abrupt transition the tire must make to regain traction and maintain the inertia of the bike can be sudden and potentially dangerous. The final option is to perceive the rear wheel slip, and quickly react by carefully managing throttle input to safely regain traction.
Most of us have not yet attained the skills or reflexes to properly respond to a sudden, major loss of traction. Even on our best days our ambition can easily fool us into overestimating our natural abilities.
With traction control, the ECU is automatically correcting for rear wheel slip as it starts to happen and reevaluating to correct every few milliseconds. The result is a smooth transition back below the threshold of traction and further correction to prevent it from being exceeded. These actions occur not only in the middle of a corner, but starting off from a stop too quickly, encountering a sudden change in road conditions, or on wet manhole covers/steel plates and the like. In most cases, traction control comes with various tiered modes for different styles of riding. These range from settings with a more aggressive intervention for commuting or touring, to ones explicitly meant for racing that only intervene under the most obvious cases of unintentional rear wheel slip. One can even turn it off entirely if the need arises.
It goes without saying that traction control is in no way a replacement for competence, wisdom, or experience in riding. It is a riding aid, one which provides the opportunity for mitigating risk in street riding and safer attempts at exploring the outer limits of a bike’s capabilities at the track. Traction control has made significant strides since its first application in a production motorcycle in 1992. In fact, we’re just a few years short of traction control becoming ubiquitous among the full model ranges offered by global motorcycle manufacturers, and it is no longer relegated to the singular purpose of safety. With improved heuristics and algorithms it will only continue to get better at reacting to motorcycles being pushed to the ragged edge of adhesion.
Does your bike have Traction Control? How has it helped you?