When to Use Rear Brake Only?

Oh, good grief. Not this old chestnut again. Sorry to come late to the party, guys, and I'm only bothering to write because Naco Traficante has been kind to some of my previous posts, but let's get this right, shall we? When brakes are applied, the weight of the bike transfers forward through inertial forces, loading the front, which is why you need a bigger brake at the front and why you need to use it. Period. Now, those of you who learned to ride a dirtbike before you sat on a streetbike, already learned the hard way that the traction between the front tire and a loose surface such as gravel is easily broken, especially if you overbrake through panic and inexperience; therefore, you learned that to stop a dirtbike, rear braking only was best, because if it locked up the wheel you could tailslide it, which was reasonably controllable, whereas losing the front end was not. Similarly, those of you who learned to ride your brother's Sportster in the days when only the major highways were paved learned that street tires weren't too smart in the dirt either, and once again the rear-wheel-only braking stunt kept you the right side up. This led to the total myth about never using the front brake, which came in with the Honda CB750 in the late '60s, the first bike with a disk front brake as standard. The stopping power surprised more than a few. But nowadays, almost everywhere is paved, tires are a whole lot stickier, bikes are more than twice as fast as they used to be, and brakes are incredible: but the laws of physics are the same, which means that the front brake does most of the work - though not all. And sorry, Cherry-picker, but the engine braking on your BMW doesn't actually help: what happens is that the pinion of the shaft drive tries to climb up the crownwheel, making the bike 'sit' and unloading the front just when you need maximum traction from the tire. You need to slow the momentum of the shaft, and you need to extend the suspension slightly on braking, both of which you can do by using the back brake. Lightly (lightly, mind you) applying the back brake on its own as you go through a fast curve under power will also stop older boxers from doing that hinge-in-the-middle thing that they do, and let you keep a tighter line, again by extending the suspension and countering the pinion's errant tendencies. Try it, you'll soon see. And use both brakes for emergency stops, no matter what: even if the back brake only adds ten percent, it's ten percent you could do with at that precise moment.

It takes a long time and a lot of experience to figure out brakes. For any simple rule you make, it can be broken. The best thing is to experiement so that you learn. I recommend using front-brake-only technique for three months and see what you learn, then try adding in a little back brake.



Rear brake only is very useful at parking lot speeds. Lane splitting is another situation where the chassis-settling effect of using more rear brake can call for more rear brake than usual. A touch—just a touch—of rear brake in cornering can help settle the chassis.



But otherwise, it's all front brake all the time. The harder you need to stop, the more your weight will pitch forward and the less effective the rear brake becomes. At the extreme, if you're super hard on the front brakes, the rear wheel actually comes off the ground, making it totally ineffective. Just shy of this extreme, however, you're braking hard, and the rear is light, making it likely that any rear brake will lock the rear wheel and cause it to slide. When the rear wheel is sliding, it tends to jack-knife and come around. For this reason, I recommend learning to use front brake only, especially for the hardest braking imaginable, and only when you've wired this fully, go back and re-introduce a touch of back brake for chassis-settling maneuvers.



Sticking to a formula like 75% front to 25% back (which was an old formula I was taught a long time ago) can get you into trouble, as I learned during emergency braking situations where the rear wheel would lock and slide. I ride dirt and can handle a supermoto-esque slide, but it's not the fastest way to slow to a complete stop.



The old formulas were really good for kids like me who grew up on coaster-brake bikes or BMX bikes with only a rear caliper. We definitely needed some sort of rule to get it into our heads that we needed to use the front brake, and use it much more than the back. But I would revise that rule to now say use 98% front, 2% rear, except at parking lot speeds.



Thank you and have a good night.

I'd like to add a note on gravel, dirt, or other low-traction situations. I ride off-road and MX, and have since I was a kid. In MX the front brake is just as important as on the street. At very low, beginner speeds, it's true that a hamfisted front brake will put you down, and a ham fisted rear brake (ham footed?) will put you into a nice brake slide. But up the pace, or the slope of the downhill, and it's all front brake all the time once again. Ricky Carmichael famously said of bike tuning to his factory mehcanics, "Give me more front brake, and I'll go faster." He knew that even in the dirt, the front brake is key.



In fact, traction is so low in the dirt that it really serves to amplify the lesson that the back brake is useless when you really need to slow down.



Of course, it is possible in very low traction situations to lock the front wheel and crash. However, the solution is not to use the rear brake only, but to slow down or use much gentler force on the front brake. Otherwise, there's no alternative but to crash because your rear brake certainly won't stop you either.



Example: I locked the front wheel in wet crosswalk paint when a pedestrian stepped out in front of me, and I crashed. Should I have used the back brake instead? If I had, I would have just slid into the pedestrian, or into the intersection, which would not have been a favorable outcome. Should I have let up on the front brake? Yes, but then I would not have stopped in time. Should I have been going slower? Yes, I should have. That was my real problem.

"And use both brakes for emergency stops, no matter what: even if the back brake only adds ten percent, it's ten percent you could do with at that precise moment."



I disagree.



1. If I am using maximum braking on my Hayabusa I will not be getting even 10% from the rear, so the chance of getting the braking right without skidding the rear is near zero. Skdding the rear means I may fall even if I could have stopped, or I now can't make an avoidance swerve because I'm crossed up in a slide. Not worth it.



2. If I am using two brakes, I have to modulate two brakes correctly to avoid losing control. That's much harder when stopping in am emergency situation. I can react quicker and more accurately with a reflexive action to use the front brake only, and not even have to think about reaching or modulating a rear brake that, in reality, is doing almost nothing anyway.



3. Spending time worrying about skidding the rear takes concentration away from what I should be doing, which is modulating the front brake for maximum braking, and scanning for a way out in case I can't stop fast enough.



Lets face it, there isn't any time to 'think' in an emergency situation, and the less I have to do, the better I will be at what I NEED to do. I NEED to get on the front brake hard, and find a way out if I can't stop.



If all else fails, I'll 'lay er down' and call it a day.