Most rider coaches and engineers agree that you should predominantly use your front brake, but from there, things get a little muddy.
Some suggest you use a small amount of rear brake, and some say the situation dictates how much rear brake to use—if any.
There’s even a school of thought that says you’re better off using your front brake exclusively during emergency stops because the back tire gets so light and prone to lock up—which triggers most lowside and highside crashes.
Here’s what Keith Code said in his book, A Twist of the Wrist.
“The obvious mathematics of the situation is that the front wheel can do 100 percent of the braking and the back, at that point, just locks up no matter who you are. Learn to totally rely on the front brake for quick, clean stopping; then, if you still have a use for the rear, go ahead and use it. But realize that the rear brake is the source of a huge number of crashes, both on and off the track. I’ll leave the final decision up to you. While it is true that a motorcycle will come to a stop quicker with both brakes applied, in racing, you don’t come to a stop until you’re done.”
The engineering firm, Mechanical Forensics Engineering Services LLC, conducted tests on several different motorcycles to measure the effectiveness of front and rear brakes.
Test results showed that using the front brake by itself delivered similar deceleration g-loads as using both brakes together. The study concluded:
“A motorcycle’s rear brake contributes little (or even nothing) to the overall stopping power when efficient use is made of the front brake.”1
Similarly, James Davis, an expert witness in Motorcycle Dynamics, said:
“Since you can generate nearly 100 percent of your stopping power with the front brake on almost any contemporary motorcycle (meaning that you can reduce traction of the rear wheel to zero via load shifting), there is a pretty strong argument that can be made that you should focus your entire braking attention to the task of using it [your front brake] and ignoring the fact that you even have a rear brake. I would not go that far, however, [because] the use of both brakes together will invariably slow you down more quickly than using just one of them.”2
How Much Rear Brake?
Most say it’s best to use both brakes when it’s raining or slippery because less weight is transferred to the front tire with less aggressive braking.
Under normal conditions, however, studies suggest that adding some rear brake can help you stop about ten percent quicker than using your front brake by itself.
But using your rear brake also significantly increases the chances you’ll crash—not because you hit the object you’re trying to avoid, but because you lock up your rear tire and lowside or highside crash all by yourself!
Everyone has to make their own decision about how much rear brake to incorporate. But I’d say if your motorcycle has ABS, you’re probably better off using both brakes. If you don’t have ABS, you’re probably better off concentrating on using the front brake effectively.
* A portion of this article is an excerpt from my book Motorcycle Smarts.