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Downhill Cornering: how much can you push it?(25 posts)

Downhill Cornering: how much can you push it?cryscityrider
Sep 17, 2001 12:56 PM
Ive been riding some new routes that involve downhill cornering. The turns are basically 45 degrees (enter one way, exit fully right or left) on two lane roads. I usually enter them going 32-37mph and lean hard with braking, exiting at about 27mph. Although i am relatively new to road riding and probably need more practice, how fast can a bike handle a turn? do i need to brake at all? any tips on how to handle turns quicker? thanks!!!
re: Downhill CorneringBrooks
Sep 17, 2001 1:10 PM
Sounds quick enough to me already! ;-) If you need to brake, brake before entering the corner otherwise you might lock up a wheel and get very nasty road rash at that speed. Keep the outside foot down and weight on it, lower center of gravity, start your "line" out near the center of the road (if safe) angle towards the apex of the corner and finish your line back near the center of the road (again, if safe). Straighter lines equal faster turns. Depending on the angle of your lean, you can usually start pedaling after passing the apex of the corner. Be careful, touching down a pedal or the outside of your foot can pop you straight up in a hurry. Practice, practice, practice.

Ride safely.
re: Downhill Cornering: how much can you push it?Lone Gunman
Sep 17, 2001 1:13 PM
The last thing you want to do in a corner is lean and brake. Recipe for a broken collar bone. Some may disagree but I like to corner with the bike as upright as I can. Brake before the turn, not in the turn. To corner with the bike upright takes practice. In a right hand turn, the left pedal should be at the 6:00 position with you the rider pushing down on that pedal HARD. The right hand, in the drops, should be pulling up on the bar. To facilitate an even quicker rate of turn, pointing the right knee out gets a little more weight to the inside of the turn, and you can increase or decrease the pointing as needed for the turn.
right handKen2
Sep 17, 2001 1:54 PM
Agree with everything you say except I think the right hand should be weighted (pushing down), not pulling up, in a right-hand turn, n'est pas? That weights the front tire correctly.
right handLone Gunman
Sep 17, 2001 6:28 PM
After further review, I stand corrected.
some tipsDog
Sep 17, 2001 2:31 PM
First, no one can tell you how fast you can corner. There are so many variables, that would be impossible.

You pretty much have to develop a feel for what you, your bike, tires, and pavement can handle. It's purely art.

First, pick a proper line - start wide, hit the apex, and exit wide - assuming nothing or no one is in your way.

Second, as noted above, preferably do your braking before you start turning. If you brake while turning, some of the traction available to your tires, particularly the front, for cornering will be used for braking - there is only so much traction available, and you want to use it all for cornering.

Develop confidence. At slower speeds, with no cars around and in safe areas, start exploring the limits. See just how far this thing will lean over before slipping. Hopefully, you'll be able to right it before sliding out too much. Better under controlled conditions than to be suprised in a race or among traffic.

Follow good descenders and watch them. My cornering speed picked up dramatically one day when I followed a good racer, about 20 pounds heavier than I, down some really long, twisty roads. I realized that if he can go that fast, then physics says that I should, too. So, I just kept up, and was shocked how fast I could go. A great lesson.

Learn to countersteer. Instead of "pointing" the handlebars, push down on the inside handlebar, usually in the drops. This actually points the front wheel in the wrong direction, which magically induces steering in the way you want to go. Works pretty well.

Stay limber on the bike through turns. You want the tires to stay in contact with the pavement. If you sit firmly and are stiff armed, the whole bike and you will bounce over bumps, unloading the tires. Bad. Tires not in contact with the pavement cannot steer you. Even unweighting the tires a bit can cause traction to drop enough for a slide. Note, this may mean that on big sweeper turns the best thing to do is to keep your pedals at 9 and 3, as opposed to outside down, to stay more poised over the bike, like a downhill mtb'r.

Listen to your tires. Sounds of gravel or sand underneath is bad. If you hear it, upright the bike a bit and back off the cornering or braking.

Keep weight balanced front to back. In a downhill turn, especially if you are still slowing, this may mean moving your body way back, and then more forward as you trail off the brakes.

Late braking is good for over all time savings, but corner exit speed is probably more important, as it will determine your speed down the next straight. So, better to brake a little earlier, corner fast and under control with proper line, than have to correct in the middle of the turn and lose speed.

Confidence makes a huge difference. You'll only get that from practice.

Dog
Countersteering??Bas Vanderwahl
Sep 17, 2001 2:59 PM
Where is this info coming from?! BICYCLING mag? Its impossible to countersteer unless the rear tire is sliding. Period.

It may seem like your bars are pointed in the wrong direction, but its just an illusion. What you are doing by straightening out your inside arm leaning the bike over more, lessening the need to steer as much.

The more you lean, the less the bars turn. The less you lean, the more the bars turn.

Try a simple 10kph test. Turn with the bike completely upright (but lean your body) and notice how much the bars need to be turned.
must be thinking of something elseDog
Sep 17, 2001 3:08 PM
"Where is this info coming from?! BICYCLING mag? Its impossible to countersteer unless the rear tire is sliding. Period." Wrongo - here are some references:

http://draco.acs.uci.edu/rbfaq/FAQ/188.html

"What is not apparent, is that two wheeled
vehicles can be controlled ONLY by countersteer, there is no other way." http://draco.acs.uci.edu/rbfaq/FAQ/168.html

http://cycling.org/lists/hardcore-bicycle-science/hardcore-bicycle-science-archive-hyper/hardcore-bicycle-science.199706/0116.html

http://www.freewheelcycle.com/descending.html

http://newton.dep.anl.gov/askasci/phy00/phy00043.htm
misunderstood?Bas Vanderwahl
Sep 17, 2001 3:28 PM
This countersteer in two of the references you listed (didnt read all) refer to initiating the lean. It said:

Countersteer

Unlike a car, a bicycle cannot be diverted from a straight path
by turning the wheel to one side. The bicycle must first be leaned in
that direction by steering the opposite way.

This is absolutely not done WHILE cornering as suggested here, but just to start the bike in a lean of the desired direction.

Typical countersteer in easily seen in a "dirt tracker" motorcycle rider. One look at a picture and you'll know what countersteer is.
Clueless!grzy
Sep 17, 2001 4:49 PM
You're so friggin' clueless and have absolutely no idea what myself and others are saying. I'm begining to doubt that you even ride a bike without training wheels or one not made by Fisher-Price.

Given that the poster asked some questions about how to corner faster you look like a dope saying things are impossible when people provide solid techniques and yet you offer NOTHING! Your only advice is so simple that it's obvious. We're talking about the less obvious here - it's what happens after you master the basics.

Go back under your rock you twit.
Immature?bEUFORD M RADDISON
Sep 17, 2001 8:03 PM
I didnt know teenagers rode road bikes.

You show us a picture of someone on a road bicycle in a right hand turn with his bars turned left with out the rear wheel sliding and I'll give you my bank account.
bEUFORD and countersteerDog
Sep 18, 2001 6:02 AM
Let's back up a minute. First, it should be obvious that I was trying to help. Second, it should be obvious, if you looked at some references I cited, that many knowledgeable cyclists agree that countersteering is not only effective, but necessary to make a bicycle corner.

We are not talking about flat tracking motorcycles, with 45 degrees of oversteer, tail hanging out, and then steering the bike against the tail through the turn. This is a different, more subtle, concept.

To make a bike turn, countersteering, maybe every so slightly, causes the the bike to lean and the contact patch to move rearward on the front tire, all because of that complicated rake and trail stuff. Yes, indeed, the front tire is pointed slightly to the left when cornering right. When I rode my bike last night, I again empirically verified this. If you don't believe me, do a Google search for terms "bicycle" and "countersteer". You'll find dozens of authoritative sources on the subject. (Incidentally, I did verify while riding that you can make a bike steer by pointing the wheel the way you want to go, too, but it is much more difficult, actually.)

If you would like to debate something, then at least try to do so in a civil manner, especially if you haven't checked some sources. To come right out of the box and call another author "foolish," effectively, as you did me, is not nice nor conducive to decent debate. I welcome good debate, but the way you went about it was irritating, and makes it less likely that we'll have a good and decent discussion on the subject. We are all here to learn, not call each other stupid.

I, myself, got a little out of control recently on the board, felt badly about it, and apologized. It happens. We'll all enjoy this better if we don't, though.

Rather than produce a photo of countersteer, how 'bout you cite me one reference that it cannot happen? I've cited several stating is does.

Doug
Dog and countersteerbEUFORD M. RADDISON
Sep 18, 2001 7:11 AM
First, you were a big help. Many great tips. I read your references also and saw that the countersteer they talked abuot is regarding initiating the turn, I know if you reread it you will see this. No where does it say that this is used mid corner or to maintain a turn.

There are no articles saying this is impossible, possibly due to the fact that there is no need for such an article. It is impossible. YOu just misunderstood the articles you read. Countersteer means to turn in the opposite direction of the turn, like a car in a powerslide. That is countersteer in a turn.

Noone is calling anyone foolish. You might want to talk to grzy? about that.

If you truly think about it, if you were in a lean to the right, and you turn the bars left, youre going down, in a hurry. THe turning forces are the only thing that allows you to lean without falling. Right?
Dog and countersteerbEUFORD M. RADDISON
Sep 18, 2001 7:21 AM
Dog,please show an article stating that countersteer is used in mid-corner, like the tip you gave, and not just to initiate the lean. Thanks.
Dog? Are you here?bEUFORD M. RADDISON
Sep 18, 2001 8:22 AM
Extend the Conceptgrzy
Sep 18, 2001 8:26 AM
Since you understand what we're talking about when counter steer is used to initiate the turn just extend the concept a bit. What I mean is there are several ways to maintain a turn. You can be "aligned" that is with the CG of the rider in a line with the CG of the bike and this line projects down to the turning radius. Call this a neutral turn.

Now you can push the bike further over into the turn with the rider CG above and to the outside of the bike CG which results in a line project to the inside of the turning radius. In this situation you can not turn the barsas much as you would if everything were in a straight line. In essence the bars are turned less than they would be for a neutral turn, that is you counter steer. Exagerate this a whole bunch and you should be able to imagine something like a flat track motorcycle with the back end sliding and the bars turned out.

Point is the orignal poster wanted to know how to turn faster and harder. One of the keys is straightening the inside arm and pushing down to tilt the bike further over and use the radius of the wheels and the movement of the contact patch to turn the bike harder with less turning of the handle bars. Most people who've riden motorcycles for any length of time will recognize this as counter steering. The analogy usually ends here since motor cycle riders typically slide their body to the inside of the bike and promote some sort of a power slide.
Grasping at best. Youre getting in so deep we can hardly hear yoBas Vanderwahl
Sep 19, 2001 10:58 AM
Stop reaching, youre digging yourself deeper.

"Exagerate a whole bunch and you'll see this in flat track"?

Come on, we all know that is a 100% different set of rules. The rear tire is sliding if you didnt notice. Its impossible to countersteer unless the rear is sliding.

Go try it on your bike, lean right and turn left. Wear some protective gear.

When you lean more by straightening the inside arm, that is not countersteer, its simply leaning more and turing the bars less.

Dog already admitted it was for initiating the lean. Your the last to defend this silly concept.

A good example of countersteer on a bike is this:

Say youre riding down the sidewalk and your right on the right edge and you want to steer away from it. You cant becasue the edge of the sidewalk doesnt allow you to turn right first to initiate the turn to the left. Have you ever experienced this? I have. Thats countersteer on a bike.

Heres another way to countersteer on a bike:

COme into your driveway real hot and turn left and slam on the rear brake. You will quickly notice the need to turn the bars to the right (in a left hand turn) as the sliding rear end kicks out.
countersteer articleDog
Sep 18, 2001 8:50 AM
I'll agree that the concept of countersteer has more to do with initiating the turn than well into the turn. Countersteer induces lean angle, which itself continues the turn. If you'll accept that motorcycles work the same way, then this article is informative.

http://sites.netscape.net/gostryter/prohibition/countersteering.html

It seems a bit wrong for me to even emphasize the use of countersteering for cycling; the real distinction is between pressing harder on the inside handlebar to induce a turn, allowing the bike and rider to lean, vs. keeping the bike more upright. Maybe the more appropriate emphasis is on the leaning concept. Leaning turns the bike. Countersteer induces lean.

Beyond that, I'll defer to the articles cited.

Doug
CountersteeringMiklos
Sep 18, 2001 9:52 AM
Countersteering-

Spot on advice. Works just the same as on my motorcycle. I have a sport bike, a Kawasaki ZX9R, and it or any other street ridden motorcycle will not negotiate a turn at speeds above 4mph without countersteer. A lot of motorcycle riders don't even know they are countersteering and will even argue the point that they dont countersteer. Most corners it is almost an imperceptible action that the un-educated riders don't notice. When you have to do an evasise manuver, it becomes blatantly obvious. When I took a motorcycle safety course with my wife when she started riding, more time was spent on trying to teach the concept of countersteering than any other single topic. Those instructors are brave, they have these beginner riders start out riding straight at them at 20mph and at the last second, the instructor points left or right and the riders have to all of the sudden turn that way to avoid hitting the instructor. All done by countersteering.

If I am going say 60mph around a left hand turn, and an obstacle is in my path, I turn the bars to the left to make the bike straighten up and go to the right and I turn the bars to the right to get the bike to lean more and turn to the left of the obstacle. Works just the same on my bicycle.

Countersteering is even more imperceptable on a bicycle, but it is there and it is the same principle. I suspect that it is not noticed as much is because the contact patch of rubber on a bicycle tire does not change as much off of center as a motorcycle with wider tires does when negotiating a turn.

I think a lot of very usefull information is taught in the motorcycle safety classes and strongly urge any motorcyclist who has not taken it, to swallow their pride and take it. I think anyone who has taken the course will say it has also had them a much safer bicyclist and driver.

Miklos
A Ray of Hope!!grzy
Sep 18, 2001 1:53 PM
Very glad to hear that someone out there knows what I'm talking about and shares a view point. Of course we could both be all wet..... ;-)

I would agree that some of the things that we do on bikes (motorized and not) are subtle to the point that we don't even know we're doing it until you go through some formalized training and analysis. I would advise the instructors to use a cone instead of themselves on the drills!!

Probably the part about these discussions is when people just say "no" or "impossible" yet have no alternaitve explanation. Sort of the NIH mentality on a personal level then spewed across the world.
A Ray of Hope!!fuzzybunnies
Sep 19, 2001 2:52 PM
One of the local cat two racers did a thesis on this for his masters degree. Seemed like a load of $hit to me but I checked every time I cournered after that and sure enough he seems to have been right. If I forced the bike not to counter steer it felt like I was sort of falling into the turn which was a little scary. Now I just turn like I always did. TTFN
re: Downhill Cornering: how much can you push it?david
Sep 17, 2001 2:51 PM
Good thread down below on this too.
In layman's terms....DINOSAUR
Sep 17, 2001 10:27 PM
Learn what your limits are and slow down a notch. I learned the hard way and spent several days in the hosptial. You can read all you want about proper techniques, but the best teacher is experience. It's like driving a car at high speeds, it's about gravity, and weight distribution. You should come into a curve high, hit the apex and come out low, faster than you entered. If you come into a curve too fast you are screwed. In other words, I wouldn't push it too much IMHO....
corneringguido
Sep 18, 2001 1:24 PM
Well, yeah. Look at cornering as scribing an arc with two wheels, already stabilized in the vertical plane, like gyroscopes, same as a motorcycle. You can sit upright and turn the front wheel, still having to lean into the turn so centrifugal force doesn't send you flying straight ahead. OR you can lean the bike far into the turn, keeping your body more upright, weighting the outside pedal, like, pressing really hard on it with your leg, which keeps the wheels firmly on the ground. You can feel the traction. Amazing how tight a turn you can do on a short wheel based racing bike, really leaning the bike into the turn but not your upper body, which helps keep weight on the outside pedal. Hinault said once he used to practice turning in a series of jerks, like one, two, three really fast changes of direction, followed by a straighter line to overcome centrigal force, regain side to side balance, then another. Caution: sliding a bicycle wheel sideways is not only a great way to wipe out, but also to warp the wheel. Don't do it.
We can't ride like the pro's..DINOSAUR
Sep 19, 2001 9:23 AM
No, we can't ride like the pro's. Why? We have the disadvantage of not being able to use the entire width of the roadway. We are lucky if we can even use the entire width of a traffic lane. We can't position our bikes where needed. We can't reach the same speed as the pro's unless it's a straight downhill stretch, then it's not skill, it's just a matter of staying off of the brakes. The average guy riding in the pro petolon has no idea of velocity vs mass, but he knows from experience how to ride a bike, honed by years of riding, and probably taking a couple of tumbles along the way. When you think about it, it gets pretty darn complicated. We effect the handling of our bikes by where we are balanced and positioned. Motor vehicles don't have this problem. Also different frame materials and geometry cause bicycles to handle different from each other. I think experience is the best teacher, unless we have the opportunity to visit a cycling camp and receive hands on advice from a cycling coach. Practice makes perfect, but be aware that no matter how good you are, shi* happens! Like deris laying in the middle your apex that throws all the math stuff out of the window. I should mention the importance of tire pressure and riding with high grade tires that are in excellent condition. A blown front tire can cause a lot of havoc if you happen to be in the middle of a curve. Come to think of it, a lot of it is just plain luck. We should be called road jockies, unstead of cyclist...