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Old 08-24-2008, 01:34 PM
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TopCatGr58 TopCatGr58 is offline
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Exclamation Yes, You/We ARE Invisible!! Part1

Hey there Xsives,

I've been planning this post/tech tip for some time, but in lieu of recent posts about riders going down/getting turned in front of, etc., seems like a timely opportunity for it! There is a lot of data that is being presented in this, I tried to put it into formats that are easy to understand and relate to!

I'm a Certified Ophthalmic Technician/Surgical Assistant with over 25 years of experience. I am at times required to fill out patient's DMV forms stating their visual function levels, so I am very familiar with the standards!

Most everybody knows that 20/20 vision is the accepted level for normal good vision, but what you may NOT know is that you are NOT required to have 20/20 vision to DRIVE! The standards of vision in Best Corrected/wearing glasses values for driving across the USA are as follows:

20/40 vision and a peripheral field of vision of 100 degrees to have the ability to drive at NIGHT.

20/70 vision and a peripheral field of vision of 70 degrees to be allowed to drive in the DAYTIME.

Now the kicker...this is ONLY ONE EYE!! A person does not need to even have a second eye!!

Commercial/CDL licenses DO require 20/40 best corrected in BOTH EYES, and 100 degrees of peripheral vision.

Some examples. A healthy person's field of vision is appx. 180 degrees, from left ear to right ear when looking straight ahead.
Below is a view taken at a local intersection just standing in the driving lane. Apologies for quality, I don't have a PANARAMIC camera, so there are defects in the Splicing, but you can get the IDEA!

Now from INSIDE the Car:

Now just showing the view to the left from the car, note the TREES, Signal Light Pole, Power Line Poles, etc.!!

Here's a view pulling up to the crosswalk of the intersection.

Now a zoomed in view, do you see the bike yet? It's on the sidewalk, but a full block away!

Now, just a few examples of comparing the view/size of a standard SUV...my Xterra and my bike! Again, didn't want to have bike sitting wayout in road next to car, so I did some splicing!
First, view at 50 feet away.

Now 100 feet away.

Now 200 feet away.

And below is a shot of my bike below a standard Speed Limit Sign. The size of the lettering for the words Speed Limit are ~4" tall, which is just a bit over the 20/200 size lettering we use for vision exams, and this photo was taken at 200 feet, 5Mp Camera at full resolution, and then when I zoomed in on the actual image, the words Speed Limit were illegible, so looks like my camera doesn't quite have 20/20 vision, but close!
Below image has been reduced in res/size for posting.

Continued in part 2
Old 08-24-2008, 01:34 PM
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TopCatGr58 TopCatGr58 is offline
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Yes, You/We ARE Invisible!! Part2


Some more background info:

The visual acuity letter sizes were determined over a 100 years ago, calculated on the density and size of the invidual light receptors(rods and cones) and so 20/20 was found to be about a 1/12th of a degree of visual field. Remember, 180 degrees or a semicircle of vision is what we have looking forward with both eyes. The fields of vision overlap with our two eyes, approx. 45 degrees towards the nose for each eye. This gives us ~90 degrees of both eyes vision. This is what also gives us TRUE 3-D stereo vision/depth perception.

Below is an example of this with vertical red lines marking the 45 degress to either side of center of overlapped vision. But note how much to the side is only seen by 1 eye.

Some more examples of reduced peripheral visions.
View of ~100 degrees of periph. vision.

View of ~70 degrees of periph. vision.

MATH: To determine how big of a "BLUR" area would be according to a person's visual acuity at specific distances. These sizes are NOT totally blind areas, but are the size that an object could be and NOT be discernible or able to tell what it is at these distances.
20/40=1/6th deg; 20/70= 1/3rd deg; 20/200=4/5th deg.

I used basic math.
Circle's circumference= Diam*3.14pi=360degrees
1/2 circumference= 1/2 diam or Radius * 3.14=180 degree
Radius 20ft *12"*3.14=~754" 180 deg
1 degree = 4.18" at 20feet.

This same formula was used for the 50ft, 100ft, 200ft, 500ft distances.

Blur Area Size and Distances
Visual      20feet   100feet   200feet   500feet
20/20       0.35in    1.7in     3.36in     8.4in
20/40       0.63in    2.1in     6.3in      15.7in
20/70       1.14in    6.3in     12.6in     31.5in 
20/200      3.25in    16.8in    33.6in     84 in
Other sizes of interest: Not including a fairing!
XS11 with rider appx. 2ft wide x 5ft high = 10 sq. feet area.
Xterra/SUV appx. 5ft wide x 6ft high = 30 sq. feet area.

Most in town residential traffic is 35mph, maybe 45mph for city. A vehicle at that speed covers 50ft a second. A common block length as ~500 feet, or 1/10th a mile, and will be travelled in 10 seconds, quicker if faster of course!

Now a few shots at the very edge of the intersection like someone would do before turning right. The bike again is a FULL BLOCK away...on the sidewalk! Just 10 seconds away at 35mph.

A zoomed in view.

Here it is ONLY 1/2 block away, a mere 5 seconds away at 35mph.

And a zoomed in view.

So, now looking back at the blur sizes for certain visions at certain distances...a person with 20/20 could have trouble seeing something that is ~8.4" big...the size of your round headlight is 7"! A person with the bare minimum 20/70 vision could not discern an object 31.5" big...remember we are about 24" wide!

Oh...but there's more!! The human eye has a Natural Blind Spot in it. It's where the optic nerve plugs into the eye, all of the millions of fibers span out from this location to map out the eye's vision, but this area itself can not see. It's about 10 degrees wide by 15 degrees high, and just 10 degrees towards the ear from center of each eye. We usually never see it because the other eye's retina sees for it. Here's an example looking straight ahead. Notice how big they are in relation to that TRUCK!

These spots' locations are in reference to the actual photo, not to you sitting here looking at your computer screen. HOWEVER, if you have a 19" monitor at 800x600, are sitting ~20" away, you can cover your right eye and look at the RIGHT dot with your Left eye, and the LEFT red dot will disappear! Vice versa for the other eye. You may have to move inward or outward a little depending on your screen size!!

Our population is aging, their eyesight is failing, their bodies and necks are stiff, so they don't often bother turning their heads very far left or right to check down the road!! And so IF they turn their heads just 30 degrees left, their right eyes 45 degrees of nose side vision will NOT cover the full 80-90 degrees left view down the road, and so their natural BLIND spot can occlude a fairly large area and won't be seen by the right eye, and you can have this situation!

So...in conclusion....it's best to ride as though you ARE invisible.

Be safe out there!
T. C. Gresham
81SH "Godzilla" . . .1179cc super-rat.
79SF "The Teacher" . . .basket case!
History shows again and again,
How nature points out the folly of men!
Old 08-24-2008, 02:21 PM
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prometheus578 prometheus578 is offline
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"Thanks for the tips, T.C."

This might also explain why women have been failing to notice me all these years.
(well, it's as good an excuse as any)

But... a good exercise you did, TC.
We've all had drivers "look right at us", yet continue to pull out in front of us.

And as you state, we are invisible.
Get used to it.

Reds can be too dark... Good visability with orange or yellow.
"Damn it Jim, I'm a doctor, not a mechanic!' ('Bones' McCoy)
Old 08-24-2008, 06:49 PM
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madmax-im madmax-im is offline
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ThankYou.. TC for confirming what i've known for some time..That we are invisible.Your photos brought it home rather precisely what it is we are up against....thats why you all see me in my nerdy Hi-Viz lime/yellow jackets.Sure leather jackets look alot nicer style wise but I get more protection and visibility in my textile jackets...
TC as a follow up you should do a study to demonstrate what bright riding apparrel and even bright headlamps can do to increase one's visiblity.
Alot has been said positive and negative about Headlamp Modulators...bottom line is they work ppl see them from a ways off...Also bikes should rig running lamps ...LEDs that emit bright White light for the front and sides of the bike and Bright amber/red LEDs for the rear.
I have been saying this for a while now "Loud Colors Save Lives"
As we all know our choices in riding gear are personal ones.Even the lack of any riding gear is a choice to be made.I wont lecture and certainly wouldnt dictate,but alot of my brothers and sisters here do not choose to wear the proper gear and have the proper visibility that goes with it.
Most importantly is to remember that no amount of gear will guarantee your saftey in every situation...but it will hopefully in most situations and also reduce the risk of serious injuries.
Also my brothers and sisters....always ride with the awareness that we are invisible to the cagers...always expect not to be seen and prepare accordingly.
1980 XS650G Special-Two
1993 Honda ST1100
Don't speak unless you can improve upon the silence....
Old 08-25-2008, 12:05 AM
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renegade_xs11g renegade_xs11g is offline
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TC, man that showed me a lot, thanks!

I drive a truck for a living, I have to admit that some things are harder to see than others, some times I think even I am invisible in the big-truck,
and it's 13'6 tall and 102 inches wide with fourteen amber LED's and 4 headlights across the front

daytime running lights help a lot...
those 'ahem' reflective vests help...
some say loud pipes ...........

no, I drive everything like it was Wonder Womans Plane
and it helps the most....

but there will ALWAYS be that 'ahem' person that just don't get it

ALL OF US NEED TO WATCH OUT FOR THEM, no it shouldn't be that way....It's just a fact of life
1980 XS11 Special aka The Monster
"My life used to be a Soap Opera, until I realized something, I own the network."
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Old 08-25-2008, 09:33 AM
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Jerry Jerry is offline
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Excellent post, TC.

A few observations, dealing with my time as an advanced amature photographer. They eye is a mysterious thing. Scientists have learned that various parts of the perform different functions; for example, the rods and cones that interperate color are more packed at the center of the eye and less dense at the peripherals, so although we can "see" at the edges of our peripheral version, motion and color take longer to be recognized than at the center of our vision. There is some evidence that suggests our eyes and brains are programmed to identify horizontal objects more quickly than vertical ones. Bikes are inherently vertical.

Add to this mix the distractions of modern driving and and recognition of bikes is impaired even further. And in my own case, 2 kids, I am constantly surprised how little they "see" when on the road. For example, I can ask them what state the last vehicle they passed was from; not a clue. While anecdotal, this lack of attention to detail seems to be endemic in most drivers.

As a rider of 34 years, I realize that riding has made me a better driver, more acute to situations and surroundings than perhaps a non-rider would be. Still, it seems to me that to many drivers consider their car to be an extension of their living room or office, take much for granted, and don't make the effort to really "see" the road and surroundings.

So, I have four general rules I follow when I ride:

Never assume other drivers see you.
Never take any situation for granted.
Don't assume anything.
Pay special attention at intersections!

The general guidlines have worked pretty well for me so far.

There are physiological and culteral reasons that make riding a motorcycle inherently dangerous. Some background in both arenas should help us survive and get to be better riders.
Jerry Fields
'82 XJ 'Sojourn'
'06 Concours
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"... life is just a honky-tonk show." Cherry Poppin' Daddy Strut
Old 08-26-2008, 01:51 AM
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xsilerating xsilerating is offline
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2 Rules 2 Ride By... Live By

Part II...

If nothing else, I try to always ride with these two rules in mind...

1) Everyone else on the road is out to get you. Keep your eyes in constant motion, know what and who is in your immediate vicinity (cars, trucks, buses, bicyclists, pedestrians, radar cops - in front, behind, to the left, to the right, look up (aircraft surveillance, birds, large bugs and swarms of bugs), look down (small animals, children, toys i.e. balls, kites, RC cars, etc.) traffic signals, stop signs, people not slowing down, people not speeding up (green light), 'cause they've got you in their cross hairs; and,

2) Don't give anyone the opportunity to use the 'excuse' that they "didn't see you". It is my personal belief that, all daylight and dusk riding be done with the headlight 'high beam' activated and, (unless you're trying to hide from someone) auxiliary lighting should be installed and USED for ALL daylight, dusk and nighttime riding (as long as your charging system can take it - the use of LED's helps). The brighter and more visible you are, the less likely you'll be missed by and amongst the masses.

Attached (hopefully) is a pic of the front end of my bike, with the high beam activated and, a set of LED driving lights installed. I've been told by a number of people that, with the LED's, I could be seen - during daylight hours - from a distance of at least 1km. (5/8 mile).

Old 08-28-2008, 04:48 AM
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egsols egsols is offline
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Eyeopener TC Should be published.

My neighbour wears a safety vest riding...I can't get to that point. As a surveyor I work in and around traffic and equipment constantly. Many cars have still come straight at me regardless of what I am wearing. I am thankfull that I have never trusted traffic and as such am still able to post. (One time I was working in the centre of a subdivision road (40kmh/25mph zone), 3:00 pm..just as school was letting out, and almost got clocked by a cop.)

Its my own personal opinion that driving a vehicle has become too easy and the manufacturers have been forced by legislation to create weapons that compensate for the ineptitude of many drivers. Although abs, traction control, etc. have their merits I wonder if they have actually contributed to high incidence of driver inattention that I witness constantly.

As has been said many times, and as I have told my neighbour in response to his distaste of my black leather riding attire, the onus is on the rider to see everything before it happens and not to rely on others seeing the rider. Ride as if everyone wants to kill you. Famous last words.... his right blinker was on but he didn't turn
79XS1100SF (no longer naked, now a bagger)
(Improving with age, the bike that is)
Old 08-28-2008, 12:58 PM
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egsols egsols is offline
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Originally post by Madmax-im

Lets not forget that cell phones,text messengers,gps nav systems and just abt any other distraction you could think of...would prolly be a cause of driver inattention moreso than say ABS brakes and traction cntrl...Jeeez the other day I saw a lady reading the newspaper while she was driving down the superslab!
Not forgotten, I guess what I was trying to say is the fact that cars are now made with a plethora of safety features that make driving them such a mundane task, the driver is no longer forced to concentrate on keeping the vehicle under control, as was the case many moons ago with none power drum brakes, no rack and pinion steering, bias ply tires, etc.

I believe this has contributed, greatly, to many being able to text, make calls, watch their nav displays, eat, do their makeup, yadda yadda yadda.

However......as I was told recently....how can you smoke while riding your bike, don't you need both hands on the bars at all times!!!! I asked if they keep both hands on the steering wheel at all times and, god forbid, ever steered with their knees.
79XS1100SF (no longer naked, now a bagger)
(Improving with age, the bike that is)
Old 08-31-2008, 09:23 AM
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Cobia Cobia is offline
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Great article

Your efforts to illustrate this are greatly appreciated, very informative, and should open many eyes to our exposure and hopefully save lives.
That is why we should all make every effort to make ourselves more visible and not be afraid to use our horns.
That is also why I installed a headlight modulator, the loudest horn I could find with out having to make major mods, and two 21 LED arrays (3 flashes then on) flanking my license plate that work in conjunction with my brake light.
This, instead of the latest trend of concealing your brake and turn signal lights to make the bike look sleeker.
Sleek = invisible to me and that is exactly what I don't want.
1980G Standard, Restored
Kerker 4 - 1
850 Rear End Mod
2-21 Flashing LED Arrays on either side of license plate for Brake Light Assist, 1100 Lumen Cree Aux Lights,
Progressive springs, Showa rear shocks
Automatic CCT
1980GH Special, Restored
Stock Exhaust, New Handlebars, 1" Spacer in Fork Springs, Automatic CCT, Showa Rear Shocks
'82 XJ1100 (Sold)
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Old 09-19-2008, 09:40 PM
planedick planedick is offline
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No longer invisible

I have found a way to not be invisible. Cops around here wear helmets that are white on top and black around the bottom. I had a black helmet that got too hot in the summer, sssoooooooo I painted the top of my helmet white and left the bottom black. I know this works, because every cage I come up behind taps the brake and slows down. I think to finish the job by painting the vents in my windshield red and blue!!! I know that black and white always gets my attention when I'm in the cage. Sort of automatic, like, you know, even in the edges of my visual range I never miss that combination and I think others are tuned into that also. Some have even told me I look like a cop back there, especially when I have on my black leather jacket too.
You can't stay young forever, but you can be immature for the rest of your life...

'78E "Pathfinder" Show bike...
Lovingly restored by Dave Delzell
Drilled airbox
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Old 09-20-2008, 03:09 PM
planedick planedick is offline
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Looks like...

What do you think?

It Works!
I can say for sure that the black and white helmet makes 'em see me. They even let me know they see me by tapping the brake or at least slowing down for a little. I will say for sure that it works.
You can't stay young forever, but you can be immature for the rest of your life...

'78E "Pathfinder" Show bike...
Lovingly restored by Dave Delzell
Drilled airbox
Tkat fork brace
Hardly mufflers
late model carbs
Newer style fuses
Oil pressure guage
Custom security system
Stainless braid brake lines
Old 04-06-2009, 09:37 PM
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DGXSER DGXSER is offline
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Very excellent TC! Lots of stuff they did not cover in my MSF course.

One concept I have drilled into my little pea brain also is that when someone is turning left and I am not, while I am passing that SUV, the cars approaching from the left have no possbile way to see me. So I assume someone is blowing the light and gonna cream me from the left until I pass the vehicle.

Also, when I went to buy a helmet, the guy at the MC shop explained to me that the most hit colors of cars are in order (IIRC) Grey, white, black. Because they all blend with road surfaces. The main reason I bought a helmet with colored graphics. The bike is black, I wanted something on my head to stand out!!!
Life is what happens while your planning everything else!

When your work speaks for itself, don't interrupt.

81 XS1100 Special - Humpty Dumpty
80 XS1100 Special - Project Resurrection

Previously owned
93 GSX600F
80 XS1100 Special - Ruby
81 XS1100 Special
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80 CB750 C
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Old 04-07-2009, 12:24 PM
BigDick BigDick is offline
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I take the military approved MSF course here on base monday, I just forwarded your posts TopCat, the instructor really liked the info and said he will use it. Thanks, you're really making a difference to how people will ride with this.
1980 XS11SG
Dunlop elite 3's, progressive fork springs, tkat brace
Stock motor, airbox, carbs, exhaust
ratted out, mean, and nasty
Old 04-14-2009, 09:02 PM
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CatatonicBug CatatonicBug is offline
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I hope I didn't step on toes

T.C. - I took the liberty of copying the images and the text from your original thesis for this thread, and created a bit of an informational booklet out of it. It's formatted to be printed, double-sided, on standard paper, and allows the reader to get around the "forum look" of the original post. I really liked the information you put together, and I know that the sentiment is shared by just about everyone else here. I have linked to the PDF file on my website here. If you would rather I not post it, I would not feel at all upset. Just let me know, and I will take it down.
1980 XS850SG - Sold
1981 XS1100LH Midnight Special (Sold) - purchased 9/29/08
Fully Vetterized and Dynojet Kit added, Heated Grips, Truck-Lite LED headlight, Accel Coils, Irridium plugs, TKAT Fork Brace, XS850LH Final Drive & Black SS Brake lines from Chacal.
Here's my web page devoted to my bike! XS/XJ User's Manuals there, and the XJ1100 Service Manual and both XS1100 Service manuals (free download!).

Whether you think you can, or you think you cannot - You're right.
-H. Ford

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