By Bryan Rastok

Motorcycle Trail Braking

Wikipedia gives us the definition of trail braking as "A driving and motorcycle riding technique where the brakes are used beyond the entrance to a turn (turn-in), and then gradually released (trailed off). Depending on a number of factors, the driver fully releases brake pressure at any point between turn-in and the apex of the turn."

As simple and defined as that may be, it does not answer the question as to why the technique is used or the implications of it. I would like to preface this article with a bias disclaimer: Trail braking is an extremely beneficial, yet high risk/high reward technique. Without a strong fundamental base, and proper introduction into it, I would advise not attempting the technique until rider skill levels match what is required. As a point of reference, when instructing track days or new racer schools, the technique of trail braking is discussed and discouraged. With that said, I find that trail braking is one of the most useful techniques in terms of being smooth and fast while entering a corner, and odds are you probably use this technique in some way and just don't know it.

One of the nastiest brakers in the game, Marc Marquez.

Braking before the corner- When coaching new riders on track, we start small and in sessions. Typically the first two or three sessions are sighting and track flow sessions, where the use of brakes and shifting is discouraged. This allows riders to focus on being smooth and not worry about the factors that speed and heavy braking zones bring. When we start to introduce braking, this is where the mental stress starts to add up, and for some, causes overload and target fixation. Shit gets real scary when you are cruising down a back straight, throttle pinned in top gear and all of a sudden, there is no more track. The mental load of speed, closing distances and physical forces is a lot and to complete the upcoming turn, the rider needs to slow the bike, so why make it more complicated? This is one example of why we teach to finish all of your braking before you enter the turn. It is a safe and smooth way to get to and enter a turn. This theory applies for both street and track use.

Simple graphic displaying all braking being done before tipping the bike into the turn. This is often the graphic used when breaking a corner down into simplified parts and the inputs needed.

Track Day / Racing- Let's forget all of what you have read so far. Although it is not taught to novice track day riders or racers, lap times significantly fall when effective trail braking occurs. Gridding up and making it through a race is "easy" as long as you are consistent and safe. With experience that consistency will grow and times will fall, achieving higher finish results and maybe even podiums. But what happens when you progress through the never ending levels of skill set is a sudden jump in ability and competition with each step: Track day level one (beginner) to two (intermediate), level two-three (advanced), level three to novice racer, novice racer to expert, expert to pro and so on until you become what is revered as "alien" status.

"Anytime you are not 100% throttle around the track, you are wasting time."

The above quote was told to me by an older AMA Horizon award winner and all around fast guy. It's a simple principle, and while it isn't physically possible, it makes perfect sense. The less time doing other things and the more time on the gas, the faster I will be. For me, a large leap in my riding/racing progression was effective use of trail braking.  Always a student of the sport, I found my progression fast, but it wasn't until I really knew how to "feel" my front end and learn to trail brake, before I could advance in the ranks. Once learned, I could start contesting others by going deeper into brake zones, setting up pass zones and riding multiple bikes effective to their attributes.

The "how to" of trail braking is simple. Start your braking with 100% of your allowed braking force and slowly trail off the pressure until you are ready to roll into the throttle. This is typically near the apex of the turn. The goal is to brake real heavy, initiate the turn and gradually roll off the brakes while equally rolling on the throttle.

Example of braking forces rolling into positive throttle around the apex of a turn.

Trail braking allows the rider to do several things:

Brake Deeper- This is the most obvious reason. Initiating your brake zone closer to the apex of the turn not only allows you to cover more ground quickly, but can get you in front of the competition.  Why start braking at the 300 ft mark when you can stay in the gas until the 100 ft mark? "Brakes only slow you down." The side effect to this is corner speed. Naturally you will be carrying more speed into the turn. Based on your setup and riding experience, this newly found corner speed can be managed through the percentage of applied braking up to the turn-in point, and at the beginning of trailing off the brakes.

Settle Suspension- Lots of things happen when riding and they are magnified exponentially with speed. The phrase "smooth is fast" gets bandied about almost to a fault, but it rings true with every new riding skill we implement. For 99.9% of you, the front end of your bike has springs and some sort of hydraulic shock. Aggressively grabbing your front brake causes the front end to dive and those springs to compress and when you let off the brake and get into the gas the bike's suspension unloads and raises back to its natural height. This abrupt up and down action is called the pogo effect and is detrimental to tire traction, corner speed and corner exit. The goal is to transition smoothly off the brake and onto the gas at a balanced rate, allowing the rider to precisely control the rise and fall of that weight transfer. The act of trail braking forces the rider into this smooth transition.

Dictate Corner Exit Location- Another piggyback off the effects trail braking has on suspension is the exit of the corner. When the brakes are applied, the suspension shortens, and a side effect of this is a shorter wheelbase. A shorter wheelbase allows for more of an acute turning radius. By adjusting your brake pressure, you can manipulate the wheelbase of your motorcycle and increase or decrease the turning radius. This will have a major effect on bike placement at the exit of a turn. Situations dictate different needs and having more wheelbase/ suspension travel due to less braking and more speed, will put you to the outside of an exit. More braking, less travel and less speed will keep you on the inside.

Trail Braking and Traction- I have prefaced much of this article with warnings to this technique and reserving it for those capable through supported experience. Trail braking is a fantastic technique, yet borders on the razors edge of disaster due its combined effects on traction. There are many variables which effect the traction of a motorcycle tire: temperature, pressures, surface type, precipitation, bike setup and rider inputs. For the sake of simplicity, lets imagine we are speaking of trail braking in a vacuum and none of those non-rider factors matter. Think of it this way, if you value available traction at 100%, you have 100% traction currency to divide between braking, acceleration and lean angle. Example:

  • 100% Traction- 60% Lean Angle -20% Throttle = 20% Available traction
  • 100% Traction- 60% Lean Angle -40% Throttle = 0% Available traction (crash)
  • 100% Traction- 50% Lean Angle -30% Brake = 20% Available traction
  • 100% Traction- 60% Lean Angle -50% Brake =  (-10)% Available traction (crash)
The "traction circle" is an easy chart showing how each input affects the other.

The forces required to accelerate, or to brake, take away from your most valuable resource, traction. This is why it is considered a fine balance between doing it well or replacing a lot of broken parts. Feel is very important as this is the only indicator you have while on the bike. Assuming the suspension setup is working for you, you can sense the front end and load on the front tire. This front feel is important as it will dictate how much pressure you can apply to the front brake lever. Think of how the front end and brake lever feels when riding down the road and you have to panic stop. That feeling you have of "if I pull the lever any harder, the front will lock up," that is what I am talking about and the feeling of your brake and traction limit. This same feeling applies as you start tipping the bike over, only now the feeling comes on much quicker as you are adjusting your braking/steering/traction percentages.

Street Riding- Everything you have read above still applies to street riding. When comparing it to track riding, there are two factors that will change your application of trail braking heavily. The first condition that is much different than track riding is speed. When more speed is introduced, inputs need to be more refined, as all actions and feedback is magnified exponentially. Daily road riding is not the race track, so we do not have to contend with the same forces. You probably are using the trail braking technique daily and not even know it: following traffic through a turn and need to slow speed or coming up to a long sweeping on/off ramp.

The second factor to street riding is the element factor. Yes, racers race in the rain, but I am referring to more than just precipitation: uneven surfaces, oil, debris, and wildlife are all factors that can have serious impact on your traction percentages. It is important to keep this in mind and to have situational awareness while applying advanced techniques,  even when going for a leisurely ride.

Go out and try it, Slowly

Trail braking is a great tool to have, but one that is learned through experience and feel. Every motorcycle is as different as riding styles, and the next time you go for a ride, try it. Baby step your way into using your brakes while initiating lean with small gradual steps of 10%, 20%, etc. brake pressure. You will start gaining that "feel" slowly and start to understand how your bike reacts a bit more. Ride safe.