How to brake properly?

[mister]

Mullan,

Try this...

Go to an empty parking lot. Find yourself a Start Point and a Break Point. Ride in a straight line until you hit 25mph. Then stop as quick as you can with just your rear brake, aplpy the brake only when you hit your Brake Point. Take notice of where you finally pull up. THEN, do the same but apply Front Brake Only. Take note of where you pull up - notice how you stopped faster. THEN, do the same again but this last time apply Both Brakes. Notice how you pulled up even quicker still.

For new people, any slow speed maneuvering and braking should be done with the rear brake only. Grabbing the front will compress the front suspension and the bike will turn in and down you will go.

For those with experience on their bike, they can use whatever brake they like while slow riding - because they have the experience on That Bike to know how much/little front brake to apply.

Riding Twisties: If you are leaning over and cornering and you need to brake, applying front break will stand you up More Upright. But here's the thing, even if such is recommended in a course, the newer rider will then become fixated on what is now in front of them. All thought of getting around the corner will vanish. And the thought of Stop Stop Stop before running off the road will be their only thought. The trick is.... let go of the front brake and now lean back into the corner at your reduced speed.

Alternatively, just use your back brake in the twisties. It will allow you to lean and take the corner as you slow.

Better yet... do all your braking Before the bend. Slow in fast out. 

And even better... practice Pace Riding - no brakes other than correct gear choices and engine braking. It forces you to Read the road better.  (Of course, if you are still too hot entering a corner you need to brake.)

The percentages of front brake vs rear brake Change over the course of the braking action. Initially, they may start at 50/50. But as more weight moves forward the rear amount decreases while the front increases so less rear brake should be applied lest you lose traction. As a more stable slowing speed is achieved, the front decreases again and the back increases. The actual percentages fluctuate during any particular braking event.

Trying to mentally/consciously do the above while braking is not possible. It happens instinctively AFTER time spent riding.

So start using Both Brakes while riding and you'll learn how much pressure to apply to each and how to change those pressures during a Braking Event.

Michael

[romulux]

The percentage numbers are sort of silly ("70% front, 30% rear") and aren't really accurate of anything.  If you have good tires, brakes, and road surface, you can apply enough front brake to make zero rear rear braking possible.  If you tried to apply that same force to the rear brake, you would just slide the rear tire.

Mullan, there are a lot of good books out there you might be interested in.  Start with Proficient Motorcycling and the sequel, both by David Hough.

Think of what happens when you apply the brake.  The rear becomes lighter as weight shifts to the front.  If you try to stop with the rear brake, you will initially have good braking power.  As you increase the pressure on the rear brake, the rear end becomes lighter and traction at the rear tire decreases.  Your ability to brake decreases corresponding with that loss of traction.  Eventually, you'll skid the rear.

The inverse happens up front.  As you brake, your front compresses due to more weight.  That weight pushing down on your front tire increases traction and you get a corresponding increase in available braking power the more you brake, up to the limit of traction provided by the tire and road surface.

Your ability to stop fast is for the most part determined by how you use your front brake, not the rear.

You're absolutely right if you had hit that patch of oil while your front was heavily stressed from braking, you would very likely go down, so it is situation dependent.  If you're moving through a curve and want some braking to stabilize yourself, the rear brake is very useful.  Same for at low speeds, you can drag the rear brake while pulling with the engine to keep yourself stabilized.

Rythmic pressure can be from a slightly warped front rotor.

Haha, please don't believe all this. Braking forces are way more complicated than I think Romulux gives them credit for, and assuming the rear brake is worthless is just not the way to ride if you're new. The best solution is to learn how to use both brakes properly, and not just ignore the brake you don't understand.

I will however 2nd that the feeling your getting would be from the rotor, and not the brake pads. Does the rotor look worn, or can you feel and bumps if you run your fingers a long the sides of it? The GS isn't packed with high quality components, so you might just be feeling what the GS does, but your rotor could also need replaced. It's hard for anyone to say without actually seeing it.

This is a good thread.  There's a lot of opinion in general about braking and in curves especially, with a lot of people saying "don't touch the brakes in a curve unless you stand the bike up first".  But, this is easy to google and read about.  The various thoughts are interesting, but I have to agree with mister.  Go to a parking lot and test things out to become comfortable with it yourself.

On the topic of front brake/rear brake there's an equally large number of opinions.

Here are some numbers.

If you don't want to read it, here's a summary:

- braking with both brakes will on average produce the highest rate of deceleration (0.76g), with front brakes close behind (0.6g).  Rear brakes by themselves were capable of only on average 0.36g, less than half of combined and only a little over half of front brakes alone.  The unit of measure here is (g), or fractions of 1 gravity or 9.8m/s^2.

The conclusion is in part:

A motorcycle's rear brake contributes little (or even nothing) to the overall stopping power when efficient use is made of the front brake.

but with the warning:

Effective front brake use, however, is highly skill dependent, and though modern motorcycles can commonly reach 1g, most riders are not that skilled.

tt_four, could you point out what you didn't agree with what I said?  I'm interested cause I usually like your posts.  I never claimed the rear was worthless (I said something opposed to that), and I use the rear all the time myself.

[tt_four]

tt_four, could you point out what you didn't agree with what I said?  I'm interested cause I usually like your posts.  I never claimed the rear was worthless (I said something opposed to that), and I use the rear all the time myself.

I have a fan!

In general I'm not going to give anyone a hard time about how they brake because I know there are several safe ways to do it, the only reason this whole thread worried me is because it was someone new to riding that was asking about the best way to brake, and in that kind of situation I don't feel like we should all be throwing out different opinions about what's best, and hearing you say what I assumed was you telling him not to worry about the rear brake, just didn't sound like the way to set him on the best possible learning curve.  Personally I just try to do all my braking before the turn so I don't have to worry about it in the middle of a turn, but everyone does it differently.

As far as what it was in your post that I really got stuck on, and I'll admit I was at work when I was reading it so I don't even think I made it to the end, or really read it in detail, was the part about the way the weight of the bike shifts when you brake. It seemed like your idea was that the way the weight shifted on a bike when you pressed the back brake, would make the rear of the bike lighter. It's true that grabbing either brake is going to shift the bikes weight, as well as your weight, but I didn't want to get things confused between what happens when you grab the front brake as opposed to the rear. Grabbing the front brake will shift the bike forward around the front wheel. That's why the rear of the bike could lift off the ground when you grab enough brake(although not really an issue on the GS). If you were to only grab the rear brake, there will be a big shift of weight to the front of the bike, but this time the pivot point is the back wheel, and all that additional weight on the front wheel is transferred energy that used to be momentum. The weight of your body moving forward will take a small amount of weight off your back wheel, but for the most part I don't think you're losing enough weight off of your back end by only grabbing the rear brake to cause you to lose traction on your rear wheel. Gradually applying more braking force is the main culprit to that one. The reason I think it's all too complicated to try and explain to someone who's still trying to learn how to ride and brake properly is because the fact that the two weight shifts are different. Grabbing the front brake is shifting weight from the entire bike to the front because it's trying to turn the front wheel into a pivot and all the weight is now put on that one point, pushing the rear brake is shifting speed/energy into the front of the bike with the pivot being the back wheel, and the wheel is practically being dragged behind it, not actually lifted up. I feel like an easier way to picture it would be to pretend like there were scales under both of your wheels, say the GS and rider combined weigh 600bs, so as you're cruising down the road you've got 300lbs on the front wheel, and 300lbs on the rear wheel. If you grabbed as much front brake as you could while still keeping the rear on the ground you could have all 599lbs on the front wheel, 1lb on the rear wheel, not to mention all the force from slowing the bike down. I haven't had a physics class in a long time, so I'll say maybe it's an additional 200lbs of force that once was speed, and is now energy created by you slowing down. You've now got 799lbs on the front wheel, and 1lb on the rear wheel. Clearly a weight shift that lightened the rear of the bike. Now if you're riding in the same exact situation but only used the back brake, so the weight is shifting around the rear wheel instead of off of it, you'd still have that same 200lbs of energy/force transferring to the front wheel, and yes all of the oil, gas, your body, whatever else will want to move forward, but there's absolutely no way just using the back brake to really lighten the back wheel in this situation since it's actually the pivot point. I don't want to say you'd be at an even 500lbs on the front wheel and still at 300 at the rear, because stuff does shift, and like I said, no physics class in about a decade, but in this situation your back wheel is also receiving plenty of that speed converted to energy transferred to it as well. If a bike had a tall enough center of gravity and a soft enough suspension it would technically lean the bike forward, and just manually shift weight from the back of the bike to the front simply because more of the bike is now over the front wheel, but in the case of a motorcycle like this the center of gravity is low enough, and the front suspension only moves down and not really forward, so that's not too much of a factor.

Now the next time I go riding I'm gonna have to find an empty street and just keep stomping on the rear brake to see what I can notice from actually feeling it, but that's all just how it works out in my head.

The other thing I wouldn't say I didn't agree with, but definitely noticed, was when you said you'd very likely go down if you the front wheel was heavily stressed under braking. That's definitely true, and it you're only riding in a straight line that would definitely be the worst scenario because you could do the same with the rear brake and just skid the back tire instead of going down, but in the next sentence you went back to talking about braking while you're turning, and if your rear is heavily stressed from braking while you're in a turn, you'll go down just as well as you would from the front, because mid turn with oil on your back tire would probably be beyond the point of saving.




Is there anyone here that understands braking affects on suspension well? The front suspension will definitely compress whether you're using the front or the rear brake, and the rear would expand if you're using the front brake. Does anyone know much about what a rear suspension does if you only use the rear brake? I browsed youtube for a while to see if I could find any videos of guys skidding on motorcycles using only the rear brake to see if the rear suspension was expanding or staying where it was, but I'm not coming up with anything good.

The other thing that complicates this more, is that most forces from braking or accelerating, because of the low center of gravity, is a forward or backward force, and the only reason that up and down forces come into play is because that's the direction the suspension travels. Technically when you grab the front brake it should only be a backwards force, but because the center of gravity is slightly higher than the contact point of that force where the tire meets the ground,  it's using force as a lever to lift the rear. With the rear suspension, the forward force of the bike on the rear wheel is really just pulling forward, but the friction of the tire on the ground then tries to use that force as a lever around the contact point of the rear tire and the ground to the front of the bike, and since there rest of the bike can only pivot around that point, it pushed the front down, but doesn't really lift the rear.

Side note again not really related to the GS..... but a lot of people who have a hard time trying to wheelie some motorcycles are making it harder because they're pulling up on the handlebars. They figure the front end should come up to do a wheelie, but really it's more about inertia, pivots, torque, and whatever else, and really they need to pull back on the handlebars, because a wheelie is really the back wheel trying to force itself under the center of gravity of the bike, and the center of the bike trying to force itself over the back wheel. The front wheel moving up is just the side effect.

[Homer]

Brakes are for suckers. 

[Worm]

Burning, yes they did make us do that maneuver. We basically got going about 18mph and went into a corner and when you got to a certain cone, you straightened the bike then did an emergency stop once upright.

[plewis51]

Burning, yes they did make us do that maneuver. We basically got going about 18mph and went into a corner and when you got to a certain cone, you straightened the bike then did an emergency stop once upright.

Same here during my safety course. They stressed on the fact to never brake while cornering as well.

[romulux]

In general I'm not going to give anyone a hard time about how they brake because I know there are several safe ways to do it...

Woah, quite a post.  Thanks for the response.

I agree with pretty much all that.

Motorcycle dynamics are very complicated and it's not like I actually know what I'm talking about.  I stand by what I said though it is a simplistic description of what's occurring.  I think we're saying more in agreement than not.

And I think braking with the rear brake unloads the rear suspension exactly like braking with the front does, but to a much less noticeable degree.

I'm going to have to really pay attention to it myself next time I'm out and see what I think afterwards.

The other thing I wouldn't say I didn't agree with, but definitely noticed, was when you said you'd very likely go down if you the front wheel was heavily stressed under braking. That's definitely true, and it you're only riding in a straight line that would definitely be the worst scenario because you could do the same with the rear brake and just skid the back tire instead of going down, but in the next sentence you went back to talking about braking while you're turning, and if your rear is heavily stressed from braking while you're in a turn, you'll go down just as well as you would from the front, because mid turn with oil on your back tire would probably be beyond the point of saving.

Absolutely!

[mullan]

Thanks to everyone!  I will take time to practice somewhere quiet for sure and take a course after my French is good enough to understand the local instructors. The practice will help me deal with a serious emergency when I won't have the chance to think about the dynamics of the bike or physics equations.

As I said, I am a slow rider (or, more to the point, I stick to speed limits and read signs and the road ahead upon approach of a corner) so I think this has primarily kept me out of trouble despite not being so knowledgeable on brakes. 

It seems to me that the general consensus is to use both brakes in non emergency situations, but to use both (AND primarily the front) together with the braking of the engine, if possible, in emergency situations and take off the pressure on the front when the deceleration is near-complete and then rely on the back brake to control at low speeds.  I am sure even this summary is open to interpretation, but it's a good pointer in the right direction.

Does anyone think it is worth making a new thread about this "rhythmic pulsating" sensation I feel on the front brake since I was practicing yesterday?  It appears the disk of the front brake is not really straight by a matter of a couple of millimeters here or there – is this serious and worth a new thread, or something quite minor?  I suppose some chav on the street kicked the bike, as it wasn't an issue until recently.

[romulux]

I don't think it's an "OMG FIX IT NOW" emergency.  I think the brake pads may wear faster than normal if it's warped...

Replace it as your budget and tolerance of it permits.

[tt_four]

If you can see it moving, that sounds like it's definitely your problem. If it's just a little vibration through your handlebar it's not a giant issue, but if it feels like the front end is almost shaking, to the point that it makes things feel a little unstable then I'd definitely look into getting another one. If you think it's bent from someone kicking it, you could just try to kick it from the other side. haha, that's as bad of advice as I gave the kid who was asking what to do about his loose handlebar. If it's something you're gonna replace anyway, you could pull it off the bike, use a ruler you know is straight, some 2x4s and a rubber mallet, and try to straighten it yourself. If you decide you're going to replace it there's nothing to lose.

[burning1]

For what it's worth...

I actually do know what I'm talking about, and can cite the MSF course, Motorcycle Dynamics by 'Vittore Cossalter,' several books on motorcycling technique, and my own experience on a race track for pretty much anything in my previous post.

With that said... The MSF course is the best place to learn braking techniques for urban environments. More than anything, the instructors can sanity check your technique, which eliminates any possibility of misunderstanding or misapplication of something you've read. No amount of intellectual understanding can replace hands on experience and professional instruction.

It is possible to break in a corner, but it's an advanced technique. Unintentional braking in corners is one of the worst panic reactions, and a very common cause of motorcycle accidents. I would advise novice riders stay the hell away from the brake levers while leaned over, and generally discourage newer riders from covering the lever while cornering for that reason.

[Allen]

I would have to agree with burning1, get off the rear brake and learn to use the front one.  You'll be surprised how much more braking force is provide by the front; as you brake the bike leans forward increasing front contact patch and reducing rear contact patch. Practice hard braking with the front only. Have fun.