Thursday, September 25, 2008

Steering Techniques

Haha... Suddenly i have too much free time... >.> so here i am at it again... :-p i've said before that i'd be posting some tips on driving ^^ so here's an interesting article i found at http://www.koniaris.com/auto/steering/ about the various techniques involved in steering :-) enjoy the reading (since it's a really ReALLY LONG article.. :-p) and happy driving ^^
Steering a Car or Truck

Racing cars with special steering ratios and the like are outside the scope of this article or my fund of knowledge, and only street cars (yes, that includes your Porsche) and trucks are considered.

Proper steering encourages fast driving, since one can place a vehicle with precision and provide smooth inputs (a secret for speed). Proper steering also encourages safe driving, since one can avoid obstacles, retain control, and protect their arms/hands from airbag and steering wheel-related injuries.

While most people do not view an airbag as a bomb right next to their hands, this is exactly what it is. If an airbag deploys when your arms or hands are in close proximity, you could suffer severe injuries that might include broken bones. You really don't want the air bag to hit you as it is inflating---you want to hit the fully deployed air bag.

(A note to people who race: If you take your fixed 9-and-3 grip on the wheel of a street car, and are turning with your arms crossed, what do you think will happen if you should be involved in an accident involving airbag deployment? I suspect that you probably want to leave racing techniques for the track! That said, you know more than enough to decide for yourself, but remember that your race car does not have an airbag, unlike your street car, so perhaps they have to be steered differently.)

If your car hits a curb, deep pothole, or rock at an angle, and your thumbs are wrapped around the inside of the wheel, they can be broken due to the resulting violent rotation of the wheel, since the wheel's spokes can break your bones. This is relatively rare on the street, but easy to do if you are into off-road driving---keep those thumbs and fingers away from the inside of the wheel! Instead, pinch the wheel between fingers and thumbs using your forearm strength. Yes, it feels strange at first, but will become a good habit.

Steering is unbelievably important in so many regards, both for speed and safety, and yet few people give even a moment's thought beyond what they were told by their high-school driver education teacher. (If one thinks back to the quality of their high-school instruction, this should be cause for fear.)

One spends years of their life behind the wheel of a car (divide 100k miles by 45 miles per hour, and multiply by how many cars you'll own to determine your hours behind the wheel). Isn't it stupid to spend years doing something that you can dramatically improve with fifteen minutes of thought?

General Observations on Steering

If you're going at a reasonable speed on a flat surface, your car wants to go straight. If you "wind" the wheel (turn it away from center), the car will try to "unwind" the wheel (return it to center). Whenever possible, you should let the car unwind the wheel on your behalf. If the car wants to unwind the wheel too rapidly, you can use a little bit of friction with both hands and have it unwind at the correct rate. So, you only need hand motion to wind the wheel, and not to unwind it.

Unwinding the wheel requires two hands to provide friction because you are less likely to let go of the wheel by accident for a moment.

Techniques of Steering

There are many ways to manage the steering wheel of a car or truck, including palming, hand-over-hand, and shuffle steering. While no technique is perfect, shuffle steering is the most flexible and useful of the above three, and it is quite easy to master! When you switch to shuffle steering the quality of your driving will noticeably improve, and your more attentive passengers will comment about the car's smooth and uniform feel that is devoid of annoying little jerky movements while turning. In particular, note that most highway turns are arcs of constant radius, so if you select the correct steering input when you enter, no further adjustment is required until your exit.

While you should learn how to shuffle steer, TAKE IT EASY AND LEARN AT LOW SPEEDS IN SAFE PLACES. You should start at your desk and think about taking some turns and move your hands in front of you, getting used to the movements.

Note: It is common to discuss a steering wheel as a clock face. So, when one says "10 and 2," they mean that the left hand is where the hour hand points to 10 o'clock , and the right hand is where the hour hands points to 2 o'clock.

"Palming" the Wheel
Palming is a one-handed steering technique. Many people "palm" the wheel, where they press their open hand on the wheel and turn it as needed. In very old cars there was even a knob put on the wheel that enabled it to be easily turned with one hand! (I suppose that this knob must have been removed when people learned that hitting such a knob in an accident is probably very unpleasant.)



Palming works very poorly if complex steering input is required; try it on a slalom course if you get the chance, as I guarantee that your hand will slip off the wheel and you will lose control of the car and hit a cone or two. (If the driver's hand slips off the wheel it is difficult to recover control of the vehicle---and this can lead to accidents.) Palming barely works on sports cars (due to their stiffer steering). Finally, palming places your steering arm in danger of being broken in an accident due to air bag deployment: For example, if you are steering with your left hand at 3 o'clock and the airbag deploys, you might suffer a broken arm. (The symmetrical case holds for right-handed steering at 9 o'clock, of course.)

The advantage of palming is that one can drive any car with power steering while leaving the other hand free to hold coffee or a Big Mac, and this can be useful. But is it worth it to risk one's safety just to enjoy fast food in the car? I think not, particularly since I've never figured out how to dip chicken McNuggets while driving.

Don't fall into the error of thinking, "I'll stop palming the moment that an accident is about to happen," since if people had this much time to reason, accidents just wouldn't happen. If you must palm, at least get prepared to drop that giant diet coke so you can grab the wheel with two hands, and don't waste precious moments trying to put it down inside the beverage holder; you're better off having the inside of your car cleaned than sending it to a body shop for a month.

Hand-over-Hand


Hand-over-hand is (usually) a two-handed technique where the arms can sometimes be crossed. For example, there can be moments where the right hand is at 10 and the left hand is at 2. This technique is a total disaster, since an airbag deployment at moments like this may leave both of your arms broken. Furthermore, if complex steering inputs are required, the arms can get very confused and be placed in such a way that it takes considerable time to figure out how to manipulate the wheel. Inputs from this technique are often very jerky, and a car prefers smooth steering inputs. It is difficult to appreciate how ugly and clumsy this technique is until you watch people flail at the wheel during a slalom course.

Hand-over-hand also tends to result in an improper grip of the wheel, where the thumb is wrapped around the inside, and this puts the thumb at risk if the car should slide into a curb, for example. Hand-over-hand also has the unfortunate property that only one hand is actually gripping the wheel at many times, as the second hand is going through the air avoiding the first one. So, while this looks like a two-handed technique, it frequently isn't. Maximum confusion often results when one wants to change the direction of turning when one hand is on the wheel and the other is in the air trying to cross over the former, and these kinds of delays are never desirable, particularly if you're in an emergency.

Shuffle Steering


"Shuffle steering" is a simple technique for managing the steering wheel of an automobile or truck. This technique enables you to have full control of the steering input without ever getting confused, and you can seamlessly go from delicate corrections to big motions (U-turns or parallel parking) with ease. Happily, if your steering needs are even more advanced---let's say that you attend Bobby Ore's incredible stunt driving school---he will force you to use his own unique (more constrained) version of shuffle steering (discussed further on this very web page), as he does not tolerate the alternatives (palming or hand-over-hand).

In short, your left hand always stays on the left half of the wheel. Your right hand always stays on the right half of the wheel. So, the highest your hands can go is where both hands are at 12 o'clock (your hands touch their index fingers together). The lowest both hands can go is 6 o'clock (where your hands touch their pinkies together).

Note that the left hand is nearly always in position to operate the signal stalk (turn signals, etc.)! And should you be driving a state-of-the-art car with a sequential manual gearbox with steering column-mounted shifting paddles (a Ferrari 360 "F1"), your left and right hands will always be in position to change gears!

A hand can either grip the wheel or gently touch the wheel. If you move the wheel under a hand that is gently touching the wheel you should hear the quiet sound of the wheel's leather sliding against skin. If you were looking at a photograph of somebody shuffle steering, you would be unable to tell the difference between gripping and touching, as they look the same. (You could only tell by watching a video of the wheel turning.) Your hands never leave contact with the wheel. If the wheel is stationary, both hands are gripping. If the wheel is moving, one hand is gripping (the one that is turning the wheel), and the other hand is sliding, although you should "unwind" the wheel by relaxing both grips. If the wheel is stationary you can change the height of your grip (say from 11 and 1 to 9 and 3) by quickly relaxing and sliding the left hand and then doing the same with the right (or the converse, of course).

Your thumb is on the top of the wheel, pinching it between your fingers on the other side.

There is general shuffle steering, and a more restricted version invented by Bobby Ore, and they differ in minor details. I will describe both techniques, and you should choose your favorite version (or just use both as you see fit). I personally use the Ore version of shuffle steering because it is so elegant.

There is an excellent reference on shuffle steering by Tim Moser that seems to be reprinted in several web sites, and I strongly recommend that you read it; one instance is at http://www.racingschools.com/rs/Steering-p-29.html. Moser also talks about seating positions, etc.

(Ordinary) Shuffle Steering

When you turn right, it is because your right hand is pulling down on the wheel. When you turn left, it is because your left hand is pulling down on the wheel. This pulling down comes from your back muscles, and is therefore very powerful. So, if you're going to take a right turn, slide your right hand up the wheel, grip, and then start pulling down. If you "run out of wheel" (the right hand hit edge of its legal range of motion [6 o'clock]), the left hand can grab the wheel to keep it from turning, and you slide the right hand up, grab the wheel again, relax the left, and then continue pulling down with the right.

If you want, you can continue the right-hand turns by pushing up with your left hand on the wheel (while the right hand slides), and this will be somewhat faster, as you will not have the slight delay in waiting for your right hand to slide up the wheel and start pulling down again.

So in ordinary shuffle steering your hands can be in various positions on their respective sides, and you can slide the hands around to adjust where they rest. In general, when you anticipate a right-hand turn, you would slide the right hand up (say to 2 or 1) in order to get a good grip, and then you would turn. You could leave your left hand down near 6 to pull up to continue the turn, or you might leave it at 9 to hold the wheel so the right hand can go up near the top and pull further.

(Bobby Ore) Shuffle Steering
Bobby Ore has developed the ultimate steering technique, a variation of shuffle steering. In short, he adds one constraint, both hands must always be at the same height. In other words, here are some "legal" positions (given the left and then the right hand):


  • 12 and 12 (index fingers touching)
  • 11 and 1
  • 10 and 2
  • 9 and 3
  • 8 and 4 (the suggested default grip)
  • 7 and 5
  • 6 and 6 (pinky fingers touching)

Note that if you know where one hand is, you know where the other hand is.

So think of this more like raising and lowering your hands, where they are at the same height. The only exception to this same height rule would be when you are adjusting the height of your hands without turning the wheel because you feel like doing so.

Mild right-hand turn

Let's say that your right hand is at 3 o'clock. (This means that your left hand is at 9 o'clock.) You want to turn right. You relax the grip on your left hand and the right hand pulls the wheel down to 5 o'clock. (This means that your left hand slides down to 7 o'clock at the same time.) You grip with both hands again.

Mild right-hand turn
As an alternative to the above, you could raise your hands, but grip with the left (only). Lifting your hands is harder than lowering your hands (as you are being powered by weak shoulders vs. a strong back), but this works as well.

Strong left hand turn

You would pull down with the left hand. If you ran out of wheel (both hands hit 6 o'clock), you would continue the turn by moving both hands up while pushing with the right.

U-Turn (on left)

You would pull down with the left hand all the way until 6 o'clock, and then push up with the right hand all the way to 12 o'clock, and then pull back down with the left hand until 6 o'clock, etc. Remember to let the car unwind the wheel for you. You can do this faster than hand-over-hand with a bit of practice. Remember that with the Ore system both hands must always follow each other at the same height.

How I take a right turn in practice....

My hands will be resting at 7 and 5, gripping the wheel. As the turn comes up, I push up with my left hand (right follows), and then pull down with my right hand (left follows), and the car will start to turn, with my hands already back at the rest position. When the turn is nearly completed, I relax my grip and the wheel moves through my fingers (returning to center), with no hand motion, and then I grip the wheel again.

Note that you are always free to break a large movement up into two half movements: A large push (with the left hand, for example) can be a half push (left) followed by a half pull (right); similarly, a large pull can be a half pull followed by a half push. Two half movements have the property that your hands go back to where they were, e.g., back to the rest position, and the concept behind Ore's symmetrical hand movement starts to shine.

HAPPY AND SAFE DRIVING! :)
Note: it should be noted that the 8 and 4 position is highly controversial as some says it's more dangerous than the 10/2 or 9/3... here's a website that discusses its safety hazards...

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