Simply put, traction is the friction between your tires and the road surface. Several factors determine how much traction is available, including surface condition, the tires’ ability to grip the road, and the amount of “load” or pressure pressing the tires onto the surface. Managing that small patch of friction, and knowing what factors help and hinder traction, will allow you to develop “traction intelligence” that helps you predict whether there is enough grip for whatever maneuver you want to attempt.
Tires are the critical connection between your bike and the road, and so keeping in mind that tire construction, compound, condition, and operating temperature directly affect traction potential gives you an immediate leg up. To attain the greatest traction potential a tire must reach its ideal operating temperature range. Street tires are designed to provide good grip over a wide range of temperatures and to get up to temperature quickly. Race tires have a very narrow usable range and higher operating temperature requirements that take longer to reach, making race rubber a lousy choice for most street situations.
Correct inflation pressure controls tire flex to attain and maintain the optimal heat range for the greatest durability and performance over a wide range of conditions. This is important because traction quality and quantity is also constantly changing with variations in the road surface. Roads with a coarse texture offer more dimples and voids for the rubber to squeeze into, whereas very smooth surfaces, such as a steel construction plate, have very little roughness for tires to grip. Moisture and debris affects surfaces differently too. Wet pavement, for example, has reduced traction, but there is usually enough grip provided you brake, turn, and accelerate smoothly. Gravel or sand typically requires much more care.
To stay on two wheels you must become very good at identifying surfaces that may not provide sufficient grip. For example, look for variations in surface color or texture. A slick glossy surface reflects light differently than a grippy textured surface. Some hazards are easy to spot, but a light sprinkle of sand or some fluid spills can be almost impossible to see until it’s too late. One trick to prevent getting caught out by hidden hazards is to predict that a hazard is likely to exist, like gravel near a construction site. If you must ride over a surface hazard, be sure to keep the bike as upright as possible and avoid braking, turning, or accelerating.
Traction also varies by the amount of weight pressing each tire onto the surface. Basically, the more force there is pressing a tire onto the road the more traction you have on that tire. Tire load changes with every action you take; handlebar inputs from swerving and cornering cause lateral shifts in load, while accelerating causes weight to shift onto the rear tire, and braking causes load to pitch forward.
The thing to remember is that one tire loaded means the other tire is unloaded. A front tire skimming the pavement on extreme acceleration has no grip for turning or braking. Likewise, the rear tire will skid easily as the load pitches forward under hard deceleration. Being traction smart is the first step in developing a traction sense where your nerves and brain work together to recognize whether traction is sufficient or you’re near the edge. The sense of traction is transmitted through the handlebars, seat or footpegs, with good grip feeling stable and poor grip feeling vague.
Even if your senses indicate that traction is adequate, practicing smooth application of the brake, throttle, and steering inputs will help to avoid abrupt load spikes that squander available grip, as well as better prepare you to feel when traction is high and when it’s low.