How ABS Works And What It Will And Won’t Do For You

Antilock brakes explained

When a car’s tires lock up, the car just skids. When a bike’s front or rear tire starts to slide, you might fall down. Thankfully, there’s technology that can avoid unintentional skids and help you stop quickly and safely, even when the road is wet or dirty. Here’s how it works. On a non-ABS bike, your master cylinder feeds brake pressure directly to the brake caliper. On an ABS bike, fluid travels from the master cylinders to an ABS pump before continuing on to the calipers. An ABS computer, often situated on the pump, monitors brake pressure as well as the bike’s front and rear wheel speeds using stationary sensors on the fork and swingarm and splined tone rings on the hubs. When the ABS computer sees a discrepancy in wheel speed that it recognizes as a skid or an impending lockup, it’ll trigger solenoid valves in the ABS pump to momentarily reduce brake pressure to restore traction.

ABS first appeared on motorcycles in the late 1980s, and up until the early 2000s most systems were pretty crude, with untimely, coarse intervention. The systems also weighed and cost a lot. Experiences with those early setups are why lots of riders today still think that ABS sucks. But, like smartphones, battery technology, and Snapchat filters, ABS has come a long way in the past few years.

These days, ABS intervention is far more refined and subtle, even on the fundamental systems you find on beginner bikes. And that’s the thing—ABS has evolved to a point that there are two tiers of technology. You’ve got your basic safety setup, which is similar to what I described earlier and is aimed at keeping you from falling down during straight-line braking, and then you’ve got your performance systems, which are more advanced, may be geared toward racetrack or off-road riding, and are often adjustable and integrate more data channels for a more precise response that can help you ride faster, safer.

Ducati's Cornering ABS is a good example of cutting-edge ABS. In addition to the wheel-speed and brake-pressure sensors, the ABS setup on this Scrambler 1100 crunches data from an inertial measurement unit that knows how far over the bike is leaning. Using that info, the ABS computer will intervene earlier and more gently when you're leaned over to account for the reduced traction and stability a bike has while cornering. Integrating data from an IMU and other channels also enables track settings that allow you to lift or drift the rear tire, and off-road ABS modes that let you lock the rear wheel but retain ABS functionality on the front.

Impressive stuff, right? It is, but you may still be wondering if ABS is right for you. If you ride on the street, ABS is a must. It’s true, a skilled rider can still out-brake some of today’s simpler systems when conditions are perfect, but it’s not about how hard you can brake when the road is clean and dry and you’re ready for the challenge, it’s about how safely you can slow down or stop when it’s raining or the road is dirty or your tires are cold and someone pulls out in front of you. Emergency braking is what ABS is designed for, and it’s reassuring to know that when things get ugly, you can grab the lever full-strength and rely on ABS to manage threshold braking while you focus on taking evasive maneuvers.