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Old 03-23-2013, 01:26 AM   #181
Wraith Rider
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Quote:
Originally Posted by D_A View Post
You are repeatedly using peak reaction times for simple predefined tasks and applying them to complex decision based tasked.
It's not my fault if you are using less efficient problem solving strategies. "If in doubt, brake" is a very simple predefined task without any complex decision making involved. Of course, if you want to use the less efficient strategies, you have to modify your style of moving.

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The statement quoted above is the most telling. By your own admission, you have already lost that first second where the vehicle in front has been braking before you have started braking yourself. At your declared one second gap you are already dead before you, with your claimed superhuman reflexes, have started to brake.
Utterly wrong. After that one second my front is at the point where the rear of the car in front of me was when it started braking, and I start to brake. At that moment there's plenty of space between us, that will be gradually reduced to 0 at the point where both vehicles come to a stop. (In the case of same braking rates of course.)
Also the assumed reflexes aren't superhuman, they are well researched averages.

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If this is genuinely how you ride then you'd better make peace with whatever deity amuses you, because you'll be finding out for sure if they exist sooner rather than later.
It is genuinely what gives me peace while riding, because I know what is physically possible and when I not have to be afraid of whatever is going on around me.
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Old 03-23-2013, 09:52 AM   #182
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You're wrong, but you're in Germany so you'll probably be alright.

One more thing to consider, as soon as you see brake lights do you always go for maximum braking? You can react quickly to seeing brake lights, but you really don't know how hard you should be braking until you judge the closing distance, that isn't something you know immediately. I hope for your sake you reconsider
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Old 03-23-2013, 03:13 PM   #183
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I'm right, because physics in Germany are the same as everywhere else.

If I'm close enough to make full braking necessary, of course I go for full brakes and then ease off when I see the one in front moves away from me instead of still getting closer. However, it's not common that someone slams on his brakes without a reason. Nothing to reconsider.
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Old 03-23-2013, 03:23 PM   #184
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I'm right, because physics in Germany are the same as everywhere else.

If I'm close enough to make full braking necessary, of course I go for full brakes and then ease off when I see the one in front moves away from me instead of still getting closer. However, it's not common that someone slams on his brakes without a reason. Nothing to reconsider.
Retake your physics class, you will impact the vehicle in front of you between the 2nd and 3rd second traveling between 15 and 30mph
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Old 03-23-2013, 10:42 PM   #185
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But you know that "impact" requires two objects to try to obtain the same point in space at the same time? That's not the case here.
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Old 03-24-2013, 12:46 AM   #186
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But you know that "impact" requires two objects to try to obtain the same point in space at the same time? That's not the case here.
the biggest reason not to tailgate is so you can slow down more gradually so the guy behind you doesn't run over you

just cause you're superhuman doesn't mean the guy behind you is
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Old 03-24-2013, 01:03 AM   #187
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Originally Posted by Wraith Rider View Post
Utterly wrong. After that one second my front is at the point where the rear of the car in front of me was when it started braking, and I start to brake. At that moment there's plenty of space between us, that will be gradually reduced to 0 at the point where both vehicles come to a stop. (In the case of same braking rates of course.)
Also the assumed reflexes aren't superhuman, they are well researched averages.
No. You really need to go back an do your basic high school maths subject again as well as "reading 101".
In that first second the vehicle in front is decelerating , but you are NOT. The difference in speed grows sharply through that second. After one second you are NOT where the vehicle used to be you are where the vehicle in front IS. Even allowing for your irrelevant and inappropriately applied numbers you no longer have time to decelerate sufficiently before hitting the vehicle in front. There is nothing in your argument that has any basis in physics, for that to be the case you need to be using real values for reflex times and deceleration rates which have already been mentioned by several others instead of single function responses to known stimulus (the time between seeing a light and pressing a button is not a relevant reflex value for this application, there are more variables, more movements and more delays in the system that you are deliberately ignoring), it is all just making poor excuses for dangerous and inconsiderate riding technique. Very simply, you are lying to yourself and everyone else and this rubbish you insist on pushing could well get a less experienced rider killed, something you will be partly responsible for.

There is the very real possibility that you very well know that you are pushing rubbish and are simply trolling the forum. I am starting to believe this as nobody could be so utterly stupid as to genuinely believe what you are saying.
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Old 03-24-2013, 05:11 AM   #188
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@randyo
At this point we have to check our definitions. I always use real world physical break points, because everything else isn't reproducable. So tailgating for me starts at a distance shorter than 1s, when it's not longer possible to avoid collision if the one in front of you emergency brakes out of the blue. In short, tailgating is leaving less than this 1s minimal safety distance. What you refer to is adding bonus space. Additional room is always nice but under real world conditions I don't get nervous if I don't have it because I know it's not necessary, thus I don't call having no additional space "tailgating".

But please explain, why do you call me superhuman while I'm talking about well researched averages the whole time?

@D_A
How can you operate a vehicle if you don't even understand the basics of kinematics? With a 1s distance to a moving vehicle I will never ever be able to arrive at the position of said vehicle within 1s. After 1s I always will be at the point where it was 1s before while it is somewhere else. No matter how hard it brakes, given both of us abide by the laws of physics.

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the time between seeing a light and pressing a button is not a relevant reflex value for this application
Well, it's exactly what we're talking about. Seeing a (brake or turn) light and hitting the brakes.

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could well get a less experienced rider killed, something you will be partly responsible for
I am surely not responsible, to no degree, if grown up drivers go over their limits. I'm telling pure facts and everyone who is allowed to operate a vehicle is responsible to evaluate his abilities and adjust his driving by himself.

Stop trying to insult me, just because you have no understanding of physics.
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Old 03-24-2013, 05:51 AM   #189
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@randyo
At this point we have to check our definitions. I always use real world physical break points, because everything else isn't reproducable. So tailgating for me starts at a distance shorter than 1s,
like I said, you better get with the drill, 3 seconds is recommended, 2 seconds is minimum that has ever been taught and the best that most people can do but he's still a tailgater just like you cause that's the way most people drive

sure you are able to stop in 1 second, the guy behind you can't, he's gonnna occupy the space your in, sure, its not legally your fault, but your still dead

http://youtu.be/2XWK5GDBAwY

http://youtu.be/M0G66aOUzOc
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Old 03-24-2013, 06:00 AM   #190
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and sorry physics guys, human reaction time is NOT physics, if it were, it would be the same for everyone every time they braked and to drive safely you need to be prepared for the slowest, not the fastest and not even the average

when it does come to physics, again, not all vehicles are the same, I can't even come close to stopping my loaded 81 chevy van in the same distance as my V-strom

and that doesn't even take into account condition of any vehicle's brakes
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Old 03-24-2013, 07:28 AM   #191
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sure you are able to stop in 1 second, the guy behind you can't
Me neither and never claimed I were.

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and sorry physics guys, human reaction time is NOT physics, if it were, it would be the same for everyone every time they braked
It's called variable for a reason, you know? Parameters change but physics stay the same. There's more to physics than constants.

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not all vehicles are the same, I can't even come close to stopping my loaded 81 chevy van in the same distance as my V-strom

and that doesn't even take into account condition of any vehicle's brakes
That's why I tend to have an eye on the mirror while braking. If someone behind me gets too close, I release the brakes.
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Old 03-24-2013, 08:08 AM   #192
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Last weekend in Chattanooga we had a 56 year old professional architect from Knoxville get run over by a 21 year old from Mississippi in the left lane of a 4 lane interstate. He was AGATT and riding responsibly according to the witnesses who saw the accident. What really galls me is the man was dragged down the interstate after getting tagged from behind. The news stated that "charges may be filed" after the investigation. WHAT!!!! It is unbelievable that there would be any doubt as to charges!!!! In Europe if you hit a motorcycle, charges are usually filed immediately unless the accident is proven to be the motorcycle riders fault. Things here need to be changed.
Back in 2003 I got hit from behind by a 16 year old not paying attention. Bent my rear wheel and tore off a saddlebag. He didn't even get a slap on the wrist! I will say, his insurance company didn't give me any trouble about paying for damages when they realized how lucky they were that I wasn't killed.
My riding style is now to be on defense all the time, give everyone as much room as possible, wear hi-viz gear, and I even put reflective stripes on the back of my saddle bags, and have a flashing brake light. I don't ride on the highway in heavy traffic.
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Old 03-24-2013, 08:21 AM   #193
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If I'm on my bike being tailgated, I move over. Bikes don't win against cages. Been hit from behind by idiots more than once on a sunday drive, commuting and even filling the gas tank (he got a nice dent in his door from a thai knee kick). If I'm in the truck I just slow down. 6" suspension lift, 33" tires and a drop hitch do a number on their radiator if they get too close.

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Old 03-24-2013, 09:00 AM   #194
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But if you have ABS brakes you don't have to worry because they will save you EVERY time! No... Really. You can't even get hit by an asteroid if you have ABS and deer whistles are a standard feature built right into the ABS system on ALL bikes so equipped.
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Old 03-24-2013, 09:41 AM   #195
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Stopping distances for cars
Many drivers have a false belief that if the car in front starts braking they can react, brake and come to a stop, still leaving the same distance between the two vehicles.

The total stopping distance of your vehicle depends on four things:
your perception time,
your reaction time,
your vehicle reaction time, and
your vehicle braking capability.

Your perception time is how long you take to see a hazard and your brain realizing it is a hazard requiring you to take immediate action. This can be as long as 1/4 to 1/2 of a second.

Your reaction time is how long you take to move your foot from the accelerator to the brake pedal once your brain understands you are in danger. Your reaction time can vary from 1/4 to 3/4 of a second.

Other factors car reaction time and braking capability.

Table 5: Stopping distance under dry conditions
Speed (km/h) Reaction distance (m) Braking distance (m) Total stopping distance (m)
S R/d B/d Total Stopping Dis.
30km/h 5.5 5.3 10.8
50km/h 9.2 14.8 24.0
60km/h 11.0 21.4 32.4
80km/h 14.7 38.0 52.7
100km/h 18.3 59.4 77.7
120km/h 22 85.5 107.5

Source Transport Research Laboratory, UK, 2007, © Road Safety Authority, 2007

1s at a 100km/h is about 27m, therefore the above is suggesting better than 1s perception/reaction time. However as the driver in front has already gone through the perception/reaction time and you have not, you need to add, at a min 18.3m to your stopping distance or conversely deduct it from the car in front. Either way if you are closer that 18.3 meters you'll hit the car in front of you. At 100km/h 1s = 27m of distance covered. So 'if' both vehicles have the same stopping capability and if your perception/reaction time is better than 1s then you might stop in time, if not then you are having car bumper for lunch. Under 1 second perception/reaction time, every time would be damn impressive and doesn't account for factors like the car may stop faster than the bike (lots of debate on that) and that you as the following vehicle are not always absolutely focused on the car in front of you, you may be in the 1/2s eye flick to the gauges, mirror or shoulder check which is time/distance you have to add to your total stop time/distance. (and is also things prudent drivers do)

I'd say that if you are only leaving 1s between you and the vehicle in front then it is only a matter of time before you get in an accident or cause one behind you because you don't have smooth transitions between speeds and you are always jacking on the brakes to avoid accidents.

Ever find that if you ride up the ass of someone and look in the mirror someone is riding your ass? Hope they have the same perception/reaction and vehicle stopping capability or you're going to get run the fuck over.

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