Braking and turns

[Louis]

I was discussing this with a riding buddy of mine the other day and thought I'd throw it out to you folks:

Let's say you're descending a relatively steep and narrow winding road and after a straight section where you sped up, you now approach a 90* turn where you can't see if a car is around the corner or not, are you already completely done braking by the time you enter the curve, so you're no longer applying pressure to the levers, or are you still braking up until, say the apex, or some point other than where you enter the curve? Is there really only one right way to do it?

TIA
Louis

[rice rocket]

The latter is trail braking. Trail braking is faster if you're doing everything at the limit, but most cyclists don't ride at the limit of traction so it's probably a wash.

I do it as a carry over from driving a front wheel drive car. It's a bad habit in cycling though, because you leave yourself no margin for error. If you need more brakes...well, you have none (or less), you'll probably low side it.

[tannhauser]

If you're trail braking around a 90 degree corner you can't see through with the possibility of taking a wide line to the double yellow, you're going too fast.

Get your braking done before the apex.

Clear line of sight, confidence in your physical ability and ability to read the road? Let her rip.

[chuckred]

I always assume there's a car if I can't see around the corner. And there have been enough times that there has...in my lane going wide around a cyclist on the way up. I'd probably be dead with out making that assumption. Always have a bail out.

[Steve in SLO]

Louis,
Either straight-line-only braking or trail-braking can be right given the circumstances and experience of the rider.

Straight-line braking gives you a bigger safety margin entering the curve speed-wise, but taking the proper line is important in maintaining that safety margin. It is generally better for recreational riders unaccustomed to high cornering speeds.

Trail-braking can allow for a higher entry speed, and can stabilize the bike in mid-corner, but if a correction needs to be made, the rider needs to remember that the brake(s) are on and that lateral traction generally decreases with applied brakes. Trail-braking is useful in having a higher entry speed, such as late-braking in a race to hit a late apex, and in experienced hands it can make for a screaming descent.

In concert with countersteering, trail braking and taking the proper line can make a descent flow.
For clarification, I use the term 'trail-braking' to mean continued application of the brakes after the turn begins. This is how I learned it for both racing bikes and motorcycles: Apply both brakes approaching a turn, initiate the turn by countersteering, then slowly let off my front brake, then let off my rear brake, all before the apex. Never hit the apex before you can see the exit of the turn. Always look beyond the apex, far down the road where you want to go. Do not look where you do not want to go (target fixation).

[rice rocket]

http://www.youtube.com/watch?v=IqrGbiGYs6A

[ultraman6970]

+1 with steve... for the record a good bike helps too. Some bikes handle so bad that no matter how slow or fast you go after applying the brakes, the turns are always like light years off the optimum turn radius.

Some bikes can only go straight line others can do it all even brake decently.

Personally i almost never touch the brakes in the curves itself, always before then use my weight as much as possible. I don't climb so i used descend pretty good my racing days, no brakes technique always to the limit. Now cant do any haha :D

Some racers have better handling and can feel the road better than others but the bike helps a lot tho. As i said before, some bikes just cant do some stuff.

[AngryScientist]

steve's advice is very good, and in reality, so much depends on the conditions of the road, the grade of descent, radius of the curve, etc. obviously also depends on how fast you want/need to get downhill. racing strategy different from cruising strategy, to varying degrees.

to answer the question, i like to brake early and ride through the turn, but in practice, i almost always use some combination of early braking and trail braking.

experience and practice are the best to develop the feel and instincts to go downhill quickly and safely. it's a lifelong learning experience for me, and i certainly need more practice myself.

[rugbysecondrow]

I am a cautious descender, so take what I say with a grain of salt.

1) I always assume a car or deer or debris is around the corner, either coming towards me or stopped in the road, especially this time of year where I ride. Potholes in the Spring...they seem to pop up in really bad spots. :)

2) I always try to stay within myself and my limits. This means anticipating and judging the speed of descent and curve of the corner.

3) Brake/feather up to to corner, picking the best line I can for a bail out, feather or slide.

4) Once in the corner, grab my balls and ride it out. I will feather if necesary.

5) It seems that I do this quite often, especially on group rides. I weight quite a bit more than most riders, so I ofter slow down and brake much more than others so I stay with the group. Otherwise, I would be like a freight train rolling past.

Cheers,

Paul

[rustychisel]

Steve, you're overthinking it, I reckon.

Ride more, practise more, go faster. And don't forget front brake when cornering will make the bike stand and take you off your line

[palincss]

I always assume there's a car if I can't see around the corner. And there have been enough times that there has...in my lane going wide around a cyclist on the way up. I'd probably be dead with out making that assumption. Always have a bail out.

In fact, you'd be well advised to assume there's a car that's cutting the turn wide and crossing over into your lane. That happens plenty often, in my experience.

[flydhest]

I assume the question is predicated on judging the corner correctly? I remember once braking before the turn, then a bit in the turn, then stopping braking as I rolled over the gravel on the shoulder, then braking more on the grass right before the ditch.

OK, so maybe not an instruction manual . . .

[Bob Loblaw]

There's been a lot of debate about this in the motorcycle community.

Keith Code of the California Superbike School says (or said when I last took his class some years ago) you should brake until the corner entry and accelerate through the corner, building speed from entry to exit. He promotes low corner entry speed and high exit speed, says you don't want to transition into or out of the brakes while leaned over. He says by learning the course, you'll learn exactly how much speed you can enter a corner with that allows you a clean acceleration all the way through. Granted for bicycles going downhill it would only be acceleration due to gravity, but it is a sound argument.

OTOH, Freddie Spencer says you absolutely should brake till the apex. He says that you should slow as you approach the corner using only the front brake, get corner entry speed close as you can to optimal (it's an estimation game to him), then gradually feather out of the brakes as you pass through the corner so that you release them completely as you reach the apex. He says that because of weight transfer forward, that front tire traction is actually GREATER when the front brake is applied, and that you should almost always enter corners under braking.

For going fast on a bicycle I personally think Freddie's way is generally better because bicycles accelerate glacially, and higher corner entry speed generally leads to higher overall speed. I personally might choose to do either depending on the corner and conditions.

However both approaches assume a racetrack environment. In the real world there are dogs, cars, kids, potholes, sand, wet leaves, etc. Whichever approach you decide to pursue, leave yourself a margin of error.

BL

[tannhauser]

There's been a lot of debate about this in the motorcycle community.

Keith Code of the California Superbike School says (or said when I last took his class some years ago) you should brake until the corner entry and accelerate through the corner, building speed from entry to exit. He promotes low corner entry speed and high exit speed, says you don't want to transition into or out of the brakes while leaned over. He says by learning the course, you'll learn exactly how much speed you can enter a corner with that allows you a clean acceleration all the way through. Granted for bicycles going downhill it would only be acceleration due to gravity, but it is a sound argument.

OTOH, Freddie Spencer says you absolutely should brake till the apex. He says that you should slow as you approach the corner using only the front brake, get corner entry speed close as you can to optimal (it's an estimation game to him), then gradually feather out of the brakes as you pass through the corner so that you release them completely as you reach the apex. He says that because of weight transfer forward, that front tire traction is actually GREATER when the front brake is applied, and that you should almost always enter corners under braking.

For going fast on a bicycle I personally think Freddie's way is generally better because bicycles accelerate glacially, and higher corner entry speed generally leads to higher overall speed. I personally might choose to do either depending on the corner and conditions.

However both approaches assume a racetrack environment. In the real world there are dogs, cars, kids, potholes, sand, wet leaves, etc. Whichever approach you decide to pursue, leave yourself a margin of error.

BL

I agree with most of this but transferring the weight to the front wheel on a moto is different than a bike due to it having suspension.

Once the front is loaded on the bike it can be destabilized easier from chatter and bumps.

[Ken Robb]

I never want to enter a corner "faster than I can see". This means I plan to do all of my braking before I initiate a turn. If I get a surprise like sand I didn't see or on-coming traffic that moves into my lane I have options including trail-braking to change my line and/or speed to cope with the unforeseen situation.

Driving or riding on a track with controlled conditions, corner workers and one-way traffic allows more aggressive technique.

[Dave B]

This past weekend I took a motorcycle safety class, ABATE and the method they use is to slow before the turn, enter it with slower speed, and accelerate out of it. The front wheel (in a lean) can either provide traction or braking not both.

Scrub off your speed, enter the turn, lean into it and counter steer if your bike heads wide. The method they used is Slow, Look, Press, Roll.

Slow down, Look through the turn, Press the handlebar into a lean/into counter steer, and roll on the throttle.

This can work for bicycles as well. Same physics essientially.

There were a few guys who disagreed with this theory, tried it and laid their bikes down. One quit right then and there.

[tannhauser]

There were a few guys who disagreed with this theory, tried it and laid their bikes down. One quit right then and there.

Must've got his ideas from the internet.

Nothing like a reality check.

[Charles M]

There's been a lot of debate about this in the motorcycle community.

Keith Code of the California Superbike School says (or said when I last took his class some years ago) you should brake until the corner entry and accelerate through the corner, building speed from entry to exit. He promotes low corner entry speed and high exit speed, says you don't want to transition into or out of the brakes while leaned over. He says by learning the course, you'll learn exactly how much speed you can enter a corner with that allows you a clean acceleration all the way through. Granted for bicycles going downhill it would only be acceleration due to gravity, but it is a sound argument.

OTOH, Freddie Spencer says you absolutely should brake till the apex. He says that you should slow as you approach the corner using only the front brake, get corner entry speed close as you can to optimal (it's an estimation game to him), then gradually feather out of the brakes as you pass through the corner so that you release them completely as you reach the apex. He says that because of weight transfer forward, that front tire traction is actually GREATER when the front brake is applied, and that you should almost always enter corners under braking.

For going fast on a bicycle I personally think Freddie's way is generally better because bicycles accelerate glacially, and higher corner entry speed generally leads to higher overall speed. I personally might choose to do either depending on the corner and conditions.

However both approaches assume a racetrack environment. In the real world there are dogs, cars, kids, potholes, sand, wet leaves, etc. Whichever approach you decide to pursue, leave yourself a margin of error.

BL


Bob, I think both KC And the Spencer guys will also say that race conditions will dictate what's right. You cant trail brake to the limit every time, every turn or you use up your tires, and Kieth will tell you that defending a line means braking later...

if you're braking, you're moving your center of gravity forward. the fastest way around the corner is with max grip at lean and max grip comes with both your weight center or rear versus the smaller front contact patch. It's corner speed versus corner entry speed.




\
But back to the topic at had, which is a bike with a teeeeeeeeeny fraction of the contact patch of a motorcycle (which has a teeeeeeeeny portion of the contact patch of a car...)


There's damn near no real "on the limit" trail braking in cycling. Even for very good handlers.


While lean angles are not so much that there is a reduced contact patch in bicycling, that contact is small enough that virtually nobody can consistently work tires to the point where sliding around is normal and frequent. that sliding and movement is a constant when trail braking in race conditions. With cars and moto's, it's happening at several points in several corners, every single lap.


With or Without a number stuck on you some place, you should never still be braking into an apex on a bicycle, even when you can see clearly around the corner, much less a blind 90...

[tannhauser]

Lost in this conversation about trail braking is no matter what Spencer and Code say, modern MotoGP racers will brake and accelerate within the corner multiple times to pass when the race is on the line.

Ok, back to the regularly scheduled conversation.

[ergott]

http://www.youtube.com/watch?v=IqrGbiGYs6A

I could watch that all day.

:beer:

[rice rocket]

Lost in this conversation about trail braking is no matter what Spencer and Code say, modern MotoGP racers will brake and accelerate within the corner multiple times to pass when the race is on the line.

Ok, back to the regularly scheduled conversation.
They also run traction control... :p

[tannhauser]

They also run traction control... :p

Yep. The electronic nannies do some of the threshold braking instead of the brain.
It's still possible to overwhelm traction, as poor Sic demonstrated.

[Chance]

I was discussing this with a riding buddy of mine the other day and thought I'd throw it out to you folks:

Let's say you're descending a relatively steep and narrow winding road and after a straight section where you sped up, you now approach a 90* turn where you can't see if a car is around the corner or not, are you already completely done braking by the time you enter the curve, so you're no longer applying pressure to the levers, or are you still braking up until, say the apex, or some point other than where you enter the curve? Is there really only one right way to do it?

TIA
Louis
Louis, can you elaborate on your question a bit more?

What do you consider the apex? The apex of the line you will actually negotiate through the turn which may keep you on your side of the road or does the apex include the use of all available road which may put you into oncoming traffic? In racing the meaning is clear but in normal driving or cycling on legal roads and highways not so much.

Secondly, how aggressive are you riding? It’s interesting that most if not all responses are based on assumption the rider is going near the limit but you don’t actually stated that. Was that your intent or are you thinking in terms of average cyclists that may descend at 50% of available traction for braking or turning? Even at 80% choices are much different than near 100%.

If a rider takes the clipping point of a blind turn as the apex and is riding at the limit of traction then he is gambling that he won’t become road kill; and seems like an extreme case to evaluate for normal riding.

[Louis]

My side of the road only - no riding in the other lane. That's why I mentioned that you can't tell if there is a car coming up in the other lane or not. Under those circumstances I assume a reasonable rider would stay in his/her lane. However, I have ridden with folks who take the chance and cross the double line, even when they can't see. IMO that's insane.

"Aggressive" is in the eye of the beholder. I try to get down as fast as I can, but don't take risks that I think are unreasonable. (see above) I think it all varies according to both your skill set and how far you choose to push the skills you have.

What do you consider the apex?
:
:

Secondly, how aggressive are you riding?

[Steve in SLO]

Steve, you're overthinking it, I reckon.

Ride more, practise more, go faster. And don't forget front brake when cornering will make the bike stand and take you off your line

Rusty,
I don't even think of it at all anymore. After 30+ years of riding and over 150K miles it is wired into my subconscious. What I was tryong to do is explain the technique and rationale for both types of braking to those who are haven't fully sussed it out.

[tannhauser]

Honestly, if some guy in my group crosses the yellow after the turn regularly some "advice" must be given to root out that kind of behavior, friend or not. Otherwise I'm not riding with that group with him as a member.

I've got better things to do than watch him die.

[MadRocketSci]

great discussion....

I guess I trail brake. Some descents in the bay area have 2-3 linked switchback turns that are about 18%, such that there's no way you could make it through without braking through the apex. It's a good skill to have in your basket....

[Steve in SLO]

Honestly, if some guy in my group crosses the yellow after the turn regularly some "advice" must be given to root out that kind of behavior, friend or not. Otherwise I'm not riding with that group with him as a member.

I've got better things to do than watch him die.

A very smart position to take. The car that swerves to miss him may very well hit you.

[rugbysecondrow]

Honestly, if some guy in my group crosses the yellow after the turn regularly some "advice" must be given to root out that kind of behavior, friend or not. Otherwise I'm not riding with that group with him as a member.

I've got better things to do than watch him die.

Amen. I only ride with people whom I feel comfortable with.

[Bob Loblaw]

Bob, I think both KC And the Spencer guys will also say that race conditions will dictate what's right.

<snip>

With or Without a number stuck on you some place, you should never still be braking into an apex on a bicycle, even when you can see clearly around the corner, much less a blind 90...

I definitely agree with everything you're saying, except that last bit about trail braking. On a steep, technical descent, you might have no other option than to trail brake because your speed increases so quickly in the corners there's no other way to keep it in check. It follows that, depending on what your goals are in cycling and where you ride, that it's a good skill to cultivate, even if you normally try to avoid it.

BL

[dsb]

I can't remember where/when it was, but the best demonstrations of trail braking I ever saw was Freddie, or maybe Ienatsch (Alzheimer's sucks...) trail braking to the apex with their knee on the tarmac and coming to a full stop...

Since moving to the mountains I seem to find myself trail braking quite a lot on my bicycle. My ability to do it effectively has definitely improved since I put the front brake on the right lever. I don't know if it's all those years on motorcycles, or just greater dexterity in my right hand, but I definitely feel more comfortable with it configured this way... YMMV...

[CPP]

The front brake lever/right hand topic merits discussion.

I remember a multi page article in Bici Sport (very cool Italian cycling magazine) on the subject. One of the points in the article was about how the Swiss racer, Tony Rominger, crashed because of a change to a front brake lever to the left hand . Apparentlly he couldn't dose his brake grab with his left hand as well as he could with his right.

I don't know how many times I've told myself to change my brake lever configuration. This reflection always happens while I am eating or drinking on the bike and I have to brake, using the front brake with my left hand. I, like Rominger, dose better with my right hand.

[velotel]

There are no rules for how to descend on a bike. The no braking in a turn or the no braking after the apex in a turn or always ride through with your weight on the outside pedal and in the down position are classic rules that fail completely in the real world. The road has since been fixed up considerably but for a time the north side of the Col d’Izoard was a perfect example for that. There’s a section in the forest where the hairpins are so tight and the grades so steep that not braking almost all the way through the turn is just about impossible unless you’re there on the day when the road is closed to cars and you know no one is going to be in the other lane. Release the brakes and the acceleration on some of those turns is wild plus the road used to be a rough cob so the bike would bounce around like a bucking bronco. Which meant riding through with the pedals level and the butt floating over the saddle. So much for the rules.

I’d also like to present the question of turns in a downhill in a slightly different context. One that does not include any reference whatsoever to motorcycles because in my opinion the only thing a bike and motorcycle have in common is the use of two wheels. A motorcycle has a motor connected to the rear wheel which means that the motor is always affecting the bike’s balance and movements in a turn, whether the motor is accelerating or decelerating. The throttle, open or closed, automatically changes the balance and thus the dynamics in a way that is impossible on a bicycle.

On a bicycle, the throttle is always wide open and there is nothing we can do to change that simple fact because the throttle is gravity. We can only modify it’s affects by sitting up, tucking in, braking, etc.

I’ll also suggest forgetting the rule about never crossing the painted line (assuming there is one, here in France many a descent is without that line because the road is so narrow they don’t bother with it, that way everyone knows the road is narrow) because if you ignore the other side of the road, you’re limiting the speeds you can achieve in a descent.

If the road you’re on is no wider than the width of your handlebars, the line you’ll follow is clear, the curve defined by the path. Widen that path to the width of a car and all of a sudden you have the option of superimposing a curve with a longer arc on the curve defined by the centerline of the road. The longer the arc of the curve you follow, the higher the speed you carry. Add a second lane to the road’s width and bingo, you’ve opened up even more the potential arc you can follow and therefore increased the potential speed at which you can descend. This is clearly what most bike racers do on roads that are closed to all other traffic; they use all the road they can.

Those of us in the real world don’t have that advantage, at least most of the time. We have to watch out for oncoming traffic, unexpected obstacles on the road surface (sand, gravel, leaves, whatever) but we still want to widen as much as possible the arc we ride to increase speed. (If speed isn’t the goal, ride the brakes and enjoy the views.) This is achieved by delaying the apex of the turn, that point where our arc comes closest to the inside of the road’s arc. In other words we’re superimposing a wider arc on the road’s arc but it’s not a perfectly symmetrical arc. We distort it by delaying as much as possible our turn in point which allows us to have a look at what’s ahead. Up to this point braking effort is maxed, to shorten the time we’re on the brakes thus minimizing overall speed loss. This is also where the front brake is used hard because we’re basically still in a straight line. The moment we start the move into the turn, front braking is either reduced a lot or even removed entirely which means that gravity jumps back into the fray with more enthusiasm. If by some wonderful chance our now positively accelerating speed at that point is perfectly coordinated with the arc, we can let the back brake go on holiday and just relish carving through and exiting with maximum speed. Doesn’t happen all the time so we end up needing to refine our speed by continuing to apply some rear braking to restrain gravity’s antics on our line.

Back to using the full road width. If you’re on a road and you can see no cars are coming up out of the turn, assuming here it’s a right-hand turn and you’re not riding in GB or Australia or some other country where they like to drive around on the other side, I say why not swing way left, clear across the road and stay there as late as you can before diving into the turn. That way you can superimpose an even longer arc on the roads curve and, even better, the exit of your arc is going to be solidly on the inside of the turn, in other words in your lane. But if, as you’re diving into the turn, you see the road is clear, you can let the arc open up and gain even more speed by taking a wider and faster line. I suppose such tactics aren’t favorably looked upon in the states but at least here in France, it’s perfectly normal. Hell, half the drivers think they’re rally champions and drive like no one else is on the road anyway.

Our brakes are the tool we use to define the arc we’re superimposing on the road’s arc. But like Steve said, once in the turn, our primary brake becomes the rear brake. Use it without hesitation to refine the precision of the arc. But if you’ve totally overestimated the speed you can handle in the turn and you’re looking at pulling an Armstrong move across some field only you have neither the skills nor the open field, straighten out your line, hit that front brake has hard as you dare, or even harder, then as soon as you can let it go dive back into the turn with the rear brake still in action.

[Chance]

My side of the road only - no riding in the other lane. That's why I mentioned that you can't tell if there is a car coming up in the other lane or not. Under those circumstances I assume a reasonable rider would stay in his/her lane. However, I have ridden with folks who take the chance and cross the double line, even when they can't see. IMO that's insane.

"Aggressive" is in the eye of the beholder. I try to get down as fast as I can, but don't take risks that I think are unreasonable. (see above) I think it all varies according to both your skill set and how far you choose to push the skills you have.
On that basis it depends on two things, and neither is theoretical in nature as others have covered that angle sufficiently. First, has the rider done this curve before (and more so if often) and secondly, if he hasn’t and is new to this road what kind of speeds are involved.

If the curve is blind as you described to the point where a car can’t be seen then it’s reasonable to expect other factors are indistinguishable as well. As others have mentioned we always have the potential for dogs, deer, rocks, sand, water, other cyclists that just went down, and so on. Chances of encountering these unknowns are small though. What should also be of concern if unfamiliar to this road is not knowing the road's curvature, its decline, its ultimate banking, whether surface changes to less traction, and so on. If you’ve done it before you’d already know all this from previous practice runs and know what speed is reasonable. In that case it’s reasonable to go in a little fast and continue to slow prior to apex. Having stated that, on many narrow roads with constant radius there is not real apex so the speed you can hold is practically the same so you’d better slow prior to going in.

If the rider is new to this road then slowing more prior to curve makes a little more sense to reduce chance of surprises. This would give him more time to adjust speed further in case banking around the curve is not what he expected, or there is a significant dip in the road, a bridge, or other unknown that familiarity with road would have eliminated.

And then there is speed. You know it takes a lot longer distance to slow from 40 to 30 than from 30 to 20 MPH. At higher speeds it’s prudent to slow down earlier to curve, particularly on a narrow road where line can’t be altered much to slow down in an emergency or in case you miss read the road. Going into an unfamiliar blind curve at 30 is a lot different than at 40. While it may be true that a higher speed curve usually has a longer line of sight it’s not usually in proportion to the distance required to slow down or stop. Risks seem to go up exponentially with speed when you can only see so far down the road.

[Chance]

One that does not include any reference whatsoever to motorcycles because in my opinion the only thing a bike and motorcycle have in common is the use of two wheels.

There is that, but also that much of the theoretical stuff is based on racing motorcycles on a track. And there is a reason these guys ride the track many times during warm up, right? They gradually speed up to get the “feel” for every aspect of the track so there are few unknowns. No doubt they are talented but it gets easier after doing the same turn 100 times in a row. It’s a little like a crit.

It’s great that some make comparisons to motorcycles because it adds to knowledge but they are not completely applicable in many ways. Imagine what a motorcycle race would be like if held on an open road where no rider had seen the course before. They would do it for sure but it wouldn’t be the same. A race track doesn’t have as many hidden variables after extensive practice runs.

[dsb]

<snip>
It’s great that some make comparisons to motorcycles because it adds to knowledge but they are not completely applicable in many ways. Imagine what a motorcycle race would be like if held on an open road where no rider had seen the course before. They would do it for sure but it wouldn’t be the same. A race track doesn’t have as many hidden variables after extensive practice runs.
Probably a lot like this:

http://www.youtube.com/watch?v=Yrs_crq5Jf4