Antilock Braking Systems Surface Analysis
ABS, Adventure Touring, and Dirt
The sun was barely above the horizon. The temperature had just crept above freezing. I was stopped at the exit of the Manic 5 Motel, with my eyes looking north and my mind focused on the many miles of Trans-Lab gravel/dirt highway that lie ahead.
My friend and longtime expert riding partner pulled up beside me, stopped, looked north, gave me a thumbs up, and said, “I turned my ABS off. You can’t do that, can you?”
He knew my new Yamaha Super Tenere didn’t have that feature, compared to his several-years-old BMW, which has an ABS-off switch.
I could have turned to him and said:
- Share with me your thinking about turning off your ABS.
- What do you know about ABS that led to your making that decision?
- What kinds of things have you read about using ABS on gravel roads?
- What do you know about how your ABS functions on various surfaces?
- What have you learned from your braking practice sessions?
These are all decent, thought-provoking questions—the kind we might ask riders during a discussion on braking. They are the kind of questions a practiced RiderCoach Trainer like me should be primed to ask. Before reading any further, I invite you to think about and formulate an answer to each one.
But instead of asking my riding partner any of these questions, I exploded in a brief but harsh rant. I perceived his question as a pointed criticism of my new bike. In addition, I thought he was simply applying the usual adage about ABS and dirt, as well as what he had recently learned during his successful completion of BMW’s Off-Road Academy, without having actual rigorous experimentation with his bike on various surfaces and without thinking about the surface and the situation we were facing. We needed to be at our best during this adventure, and I thought that the terrain demanded and his level of expertise deserved better than the stock response.
The common adage is that you can stop quicker on dirt without ABS. Given the right dirt and a ready rider, this is certainly true. This is the knowledge many riders possess and use as a basis for turning off their ABS in situations that I believe most of us adventure-touring riders would be better advised to leave it on.
Discussions about ABS and dirt are commonplace on the Web, and the general conclusion is that few experienced dirt riders use ABS off road. The main reason, however, is not because they prioritize the importance of stopping quickly, but instead it is to allow the locking of the rear brake in order to slide around corners. A YouTube demonstration found at http://www.youtube.com/watch?v=8JhenlQlWuA shows reduced stopping distances with the ABS off. The introduction to this video states: “Here you can see the dramatic difference of emergency stopping on dirt roads or gravel [emphasis added] with abs vs. no abs.”
Is riding on a dirt road or a gravel road the same as riding off road? Are dirt roads and gravel roads the same? Are all dirt roads the same? Are all gravel roads the same? Are you an experienced dirt rider?
Alternative words for dirt include soil, earth, clay, loam, mud, muck. Alternative words for gravel include grit, pebbles, stones, rock-strewn. What about sand, silt, shale, sludge, topsoil, ground, or aggregate? All these words certainly do not describe the same type of surface. I think we set ourselves up for trouble when we lump all these surface descriptions under the heading of “dirt” and then apply the usual adage “when in dirt, turn the ABS off.”
The big advantage of ABS is in preventing a skid that causes you to lose control and crash. We don’t get to pick the time and place for an emergency stop (as in the video and when we practice). Someone or something (like a moose, on our Trans-Lab ride) will determine it for us. It’s during these unplanned stops that having an ABS system will save us.
Few riders of big adventure touring bikes are actually expert off-road riders, and fewer still actually ride off road. What we typically ride on are the public roads, some of which are asphalt with various surface hazards; and others are different forms of non-asphalt, with wide variations in surface conditions. How often are we actually on a soft, non-asphalt surface where we want to lock the rear to slide around a corner or are in need of the theoretical shortest stopping distance? Given the fact that we don’t get to pick our emergency braking times, do we want to sacrifice the big advantage of ABS in a tradeoff for the possibility that we might be able to stop quicker if at the time of the emergency the surface is just right and we are ready?
My rant: “We’re not riding some soft off-road, single-track trail, for God’s sake! We’re riding a hard-packed, rock-strewn, mess of a road.
"The likelihood of needing to stop in the shortest possible distance is slim to none compared to the likelihood of screwing up your braking and crashing your brains out.
"You can leave your ABS off if you want to, but I’d leave mine active even if I could turn it off.
"It’s your decision.”
Dan Petterson, Ed.D., has been a motorcyclist for over 40 years. He rides street, off-road, racetrack, and dual sport. He currently owns 10 motorcycles, four of which are licensed and insured for street use. He has been involved in motorcyclist safety since 1985 as a Motorcycle Safety Foundation instructor/RiderCoach and since 1990 as a RiderCoach Trainer. He is a graduate of several track schools, including all four levels of the California Superbike School. He holds a doctorate in education from Western Michigan University. Dan is a charter lifetime member of the AMA, having earned his charter lifetime membership many years ago by being a continuous dues-paying annual member for 25 years. He is the founder and current president of the Skilled Motorcyclist Association–Responsible, Trained and Educated Riders, Inc. (SMARTER at www.smarter-usa.org).