n00b totals 250 on first ride

[akima]

All of Jiggles threads are huge.

[Motofool]

Originally Posted by dfox

........The dynamic affect of braking and the change in momentum will impart additional forces to the front tire, increasing the achievable braking force..........

We are almost there, Dfox, but I still have to disagree.

In my humble opinion, there is no other dynamic force than what I have represented in my schematics.

Bike not moving: Gross 50/50 weight distribution between rear and front.

Bike moving at constant speed: Gyroscopic effect is the only dynamic moment. Gross 50/50 weight distribution between rear and front.

Bike accelerating or braking: An acceleration or deceleration force appears (F=ma), which induces a pitch moment that upsets the gross 50/50 weight distribution between rear and front. Newton's second law of motion rules all that is happening (Gyroscopic effect increases or decreases, but it doesn't affect pitch or braking). Friction is static for a rolling tire, once the skid begins, the friction becomes dynamic (which is always a smaller force than the static friction).

Copied from http://en.wikipedia.org/wiki/Newton's_laws_of_motion

"Second law: The acceleration a of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma."

Is OK that we disagree, but please remember that I only tried to grossly calculate what happened in this particular event.
I just like calculating and testing better than just guessing, even if is not perfectly accurate.

This thread explains some of the points that you and I have been discussing here:
http://www.msgroup.org/forums/mtt/to...p?TOPIC_ID=980

Here are some real test numbers for some big cruisers, none above 1g (32.2 ft/s per each second):

http://www.michigan.gov/documents/ms...s_182665_7.pdf

[Jiggles]

Originally Posted by akima

All of Jiggles threads are huge.

I must be very controversial O.o

It probably doesn't help that I spend too much time on the computer either

[miss_syn]

Originally Posted by akima

All of Jiggles threads are huge.

"Hey ladies. Look at my huge thread. "

[akima]

[dfox]

Originally Posted by Motofool

(which is always a smaller force than the static friction).

Is OK that we disagree, but please remember that I only tried to grossly calculate what happened in this particular event.
I just like calculating and testing better than just guessing, even if is not perfectly accurate.

agreed about this particular event. this all started when i asked where you got the 1g number from, because in understanding dynamics, I know you can create additional downward force during deceleration, and that's what's happening when you brake.

http://www.bikesafer.com/detail/braketime.html http://www.promocycle.com/documentat...morfrein_e.pdf (the second is a good read for the no-rear-brake crowd.)

they have measured results of average riders achieving over 1g of brake force.

now this is a very tiny bit over 1g, but considering that you wont ever have a 1.0 coefficient of friction, there are other forces at play that allow you to achieve better braking that 1g.

I agree with you on all other fronts, but there is more at play than basic physics.

[rmorse]

Originally Posted by dfox

http://www.bikesafer.com/detail/braketime.html

they have measured results of average riders achieving over 1g of brake force.

now this is a very tiny bit over 1g, but considering that you wont ever have a 1.0 coefficient of friction, there are other forces at play that allow you to achieve better braking that 1g.

I agree with you on all other fronts, but there is more at play than basic physics.

Wait, what? Physics is all that's at play here.....

[akima]

Originally Posted by rmorse

Wait, what? Physics is all that's at play here.....

He said "basic" physics... implying that the math given so far only partially describes the physical reality that occurs when braking on a motorcycle.

[rmorse]

Originally Posted by akima

He said "basic" physics... implying that the math given so far only partially describes the physical reality that occurs when braking on a motorcycle.

Ah. I missed the basic part.

[drac]

If you were really starting the braking at indicated 30 mph, which is not obvious in your short video, you were decelerating at a rate of 1.53 times the acceleration of gravity (g), in order to come to a complete stop in 17 feet.

That can't be right, the 1.53..... What I mean is, although I consider myself pretty good at panic stops I don't think I am hitting 1.5+g's. I am not discounting your math. It is more that I am thinking I need to have someone record it so I can see. I am either braking too early every time or rolling off the throttle too soon thereby decreasing my speed.

Next time, try a stopple in the same conditions for us to see if the distance can be reduced even more: I believe you could do better by making the rear tire float.

The whole stoppie deal... I can't make the ninja do a stoppie by the way I panic brake. I consistently skid the front end before the rear ever even thinks about coming off the ground. On a 600cc supersport I can get into a stoppie when I panic brake but not the 250. Sorry guys but the brakes on our little bike are really good just not superb. But then again I have only ridden with stock IRCs'

To get into a stoppie on the 250 I have to "try" and make it happen. Intentionally grab the front bakes too hard too fast while letting ALL my weight transfer to my arms. I don't do that in a panic stop.

What you can't see in a video is that, as far as weight transfer goes, when I panic stop I grab the tank a little with my knees while trying to keep my weight down on the seat and into the tank. And YES, during an actual panic stop if the "junk" isn't where it needs to be it can hurt like hell. Point being I do whatever I can to keep the CG as low and rearward as possible.

[drac]

2 Equilibrium
- Place the bike vertical
- Brace arms and legs
- Straighten torso
- Position fingers and feet

This is one thing I don't do. I know in theory the wind hitting you upper body will help to slow you down but I have just always kind of arched my back slightly and kinda let my nads get pushed into the tank trying to keep my weight down and back.

Have to play around with that a little.

[Jiggles]

I did a stoppie on the 250 with stock IRC tires.

[DevinWolfe]

This really makes me want to practice panic braking more, just to see what I/the bike can do. I felt like I could push my stock IRCs to their limit but never felt like the rear was going to come up, I likely wasn't pushing them as hard as I could have. I want to try with my new sticky Rosso IIs.

In my "offroad excursion" I skidded the front (roadwinner) for an instant, but that was at a much higher speed than is being discussed here. I would really like to see what the new tires will do. My helmet-cam has a narrow angle so I will need to figure out a place to mount it on the tank/tree.

[drac]

If you braked hard enough to get the front tire squealing then where close to the limit. Like I said with my stock IRCs' I can do stoppies but I have to "want" to do stoppies.

If we are talkng about 15mph, grab a sh!tload of front brake stoppies they are a no brainer. But a 40mph, do a stoppie and ride the front wheel for 20 feet kinda thing you have to "make" it happen.

[THE BIG SITT]

Post vid of said stoppie

[DevinWolfe]

Since my bike already has some broken plastics I will try to stoppie. I'm pretty heavy (250ish) so I have as many pounds as CCs but we'll see what happens. I will post a vid if I can pull it off.

[drac]

Here's a guy doin' a couple........ Notice his ass is up off the seat. He's forcing his weight up on his arms to get it all over the front end.

http://www.youtube.com/watch?v=eKqk8LvD3mg

You got what you asked for.

[lamchops]

Originally Posted by miss_syn

"Hey ladies. Look at my huge thread. "

[Motofool]

Originally Posted by dfox

........
http://www.bikesafer.com/detail/braketime.html http://www.promocycle.com/documentat...morfrein_e.pdf (the second is a good read for the no-rear-brake crowd.)

they have measured results of average riders achieving over 1g of brake force.......

Thanks, Dfox, those links are priceless!

They show the average reaction+braking distance for this specific case (close to 30 mph) to be 66 feet (61 feet with ABS), pretty close to the 67.1 feet calculated in post #296.

The OP never had 66 feet to react and stop before colliding.

From that first link:

"You can only maintain peak emergency braking performance by taking the time to learn the skill, and by practicing it on a regular basis."

From the second link:

"RISKS ARISING FROM A LOCKED FRONT WHEEL
Locking of the front wheel must be avoided at all costs during hard braking because it leads almost automatically
to a loss of directional control and a sideways crash if it persists longer than a tenth of a second. Fear
engendered by this physical reality means that the majority of motorcyclists under-utilize the capacity of their
front brake, especially at the start of braking. Thus it is of paramount importance to become proficient at the
start of braking because the distance traveled is relatively greater than at the end of braking.

EFFECTS OF DECELERATION FORCE
The mean deceleration for the group of 298 passes braking from 100 km/h to zero was -0.898 g in a mean time
of 3.18 seconds. During these more than 3 seconds, the rider had to manage his braking while subjected to a considerable
deceleration force against his arms and hands which must in large measure support his upper body. A
simulator designed to recreate this force would have to incline the motorcycle on its front wheel at an angle of
64 degrees.

THE EQUILIBRIUM STAGE
Each emergency braking maneuver is preceded by a stage of stabilizing the motorcycle. Although it may be
very short, it is no less important despite the fact that it is little covered in the literature. Even when the motorcycle
gives the impression of rolling in a straight line, the rider makes constant adjustments to maintain equilibrium
among different forces and the chosen trajectory. At the moment of emergency braking, this equilibrium
must be perfect and be maintained for the length of the braking maneuver."

[akima]

@drac: I find that if I'm too snappy with the front brake, the front wheel will loose traction and skid. If I progressively apply it at a slower rate, it maintains traction and I stop quicker. Presumably those people who can do stoppies on the ninjette are applying the front brake smoothly and at just the right speed in order to keep the front tyre stuck to the ground while more and more rider+bike weight is transferred onto it.

[Felipe the Ant]

Prove Keith Code and all of his racing experience, plus everyone else involved in the making of twist of the wrist, and his school with all the instructors who presumably believe the same thing wrong and then make your argument on how you can do it better

[lgk]

you cant test emergency braking with fixed objects at a known distance.
these tests only capture stopping distance.

the only way this test could be replicated is with a hidden sensor that activates a light. the rider is actually moving at speed and the sensor and light signal an emergency, forcing a stop. this way surprise is added into the picture.

their tests averaged around 65ft in a controlled environment but in the real world you can add an extra 10ft to those numbers.

[saxjonz]

Originally Posted by Renner

28mph on a residential street, which most likely should be posted limit at 20mph...nobody wants to say that this could of been avoided by not exceeding the speed limit.

If you were going 20mph, that car would of completed the U turn by the time you got to it....not trying to be a dick or anything, just pointing out the facts.

Good luck on your recovery

No, she would have hit him head on when she swerved in to his lane. What is the deal with everyone putting the what if's? You have to accept it for what it is.
It was his first ride, according to what I read. Would that have happened to me? No. I am used to idiots after 24 years of street riding I read minds. Why it wouldn't have? Because I always look for the wheels on the cars, this probably happened way too quick for him even to notice till it was too late. This **** happens all the time. ALL the time. It's the reason I like to ride cause it's a life challenge.
As far as all of the comments about what Jiggles could have doen I could say the same of that douchebag. When you crack a u-turn (they are illegal for the same reason by the way) you MUST LOOK TO MAKE SURE NO ONE IS COMING YOUR WAY!!! Point blank.
No excuse for what she did and by the way you can sue her in a civil court for gross negligence. The lawsuit could still be on if she owns anything of value. Your downtime is full of pain. I broke my knee and had five pins and a plate. I KNOW THAT FEELING ALL TOO WELL. Three O'Clock in the morning like clockwork hits those incredible pains and why no one knows. But yeah, being laid up and having to have someone care for you? Ha 36k doesn't even begin to cover that let alone the excruciating pain nor the years off your life that you will endure with some sort of setback or other. Just wait till winter for a few years you will be, if you have metal in you, feeling it and the swell and cold will make you feel miserable.
There have been so many times I almost lost my life at an intersection when people just up and run red lights, turn in front of you, which is probably the number one cause of accidents by the way, they cut your lane. THEY DON"T LOOK most of the time. That is a fact of life you will never change. Your approach to riding can change though. Sucks that it happened on your first ride.
I don't know you man but you have my empathy. I totally commiserate with you on your plight. Go after her house and property, you will get more than that sorry excuse for a payout. Not like that will ease your suffering but you should get at least something for your ordeal.
A little tip of advice: City riding sucks, you need to get out to the country where there are corners and after (better yet) do the mountain riding scene. Once you have done that you will have learned that in the mountains you can ride all day and rarely see any cars and most of the roads don't have intersections or parked cars that are potential accidents waiting to happen. Problem is now that I have experienced the best riding out there I just don't enjoy riding local too much any more. I gotta have those wild curves and lean over till that chicken strip thing is a part of history. You haven't experienced that feeling, you haven't truly experienced what it feels like to ride.

[saxjonz]

Originally Posted by akima

@drac: I find that if I'm too snappy with the front brake, the front wheel will loose traction and skid. If I progressively apply it at a slower rate, it maintains traction and I stop quicker. Presumably those people who can do stoppies on the ninjette are applying the front brake smoothly and at just the right speed in order to keep the front tyre stuck to the ground while more and more rider+bike weight is transferred onto it.

You just gotta stop riding on cheap old rubber. I have a 1200 and with my tires if I grab a handful of brake as heavy as my bike is I will endo before the front breaks loose. But I ride all the time. My tires don't have an opportunity to get hard and cracked like most riders do. If a tire lasts two seasons its good to be replaced. Dunlops are garbage.
But in favor of what you said, yeah, trying to lock up the front brakes is foolish. Still, you don't wait to hit them hard if you need to stop right away. I had that issue a few times with old rubber where I was riding at 80 and a semi cut in to my lane with no turn signals. I gripped both brakes hard and wheels locked up, cheap rubber dunlops, a few days later an idiot slammed on his brakes in front of me on purpose and both my tires locked up. New tires eliminated that.

[akima]

Originally Posted by saxjonz

It was his first ride, according to what I read.

@Jiggles: you're such a troll!

Originally Posted by saxjonz

You just gotta stop riding on cheap old rubber. I have a 1200 and with my tires if I grab a handful of brake as heavy as my bike is I will endo before the front breaks loose. But I ride all the time. My tires don't have an opportunity to get hard and cracked like most riders do. If a tire lasts two seasons its good to be replaced. Dunlops are garbage.
But in favor of what you said, yeah, trying to lock up the front brakes is foolish. Still, you don't wait to hit them hard if you need to stop right away. I had that issue a few times with old rubber where I was riding at 80 and a semi cut in to my lane with no turn signals. I gripped both brakes hard and wheels locked up, cheap rubber dunlops, a few days later an idiot slammed on his brakes in front of me on purpose and both my tires locked up. New tires eliminated that.

I just ordered a pair of Diablo Rosso 2's

[Jiggles]

Originally Posted by akima

@Jiggles: you're such a troll!



I just ordered a pair of Diablo Rosso 2's

[saxjonz]

Someone posted this up on our website and I just saw the video and had to post up. Dude, I know those feelings and especially how the mind works when you are jacked up. Was there, had to comment.
The nice part was the sympathy sex that abounded from every chick I met. All my ex girlfriends stopped by to "comfort me" was unbelievably awesome. When you take a Vicadin and do the wild thing it's unbelievably great!
Originally prescribed originally in Canada where I broke my knee on Friday the 13th afther some bare triple F Breasts stared me down and I freaked. Leaned back on my moto and well when I got up to go and find some action so did my bike.
When we ignore cardinal rules we get PHOOKED. You can lean on kickstand side and knock bike over, look like idiot for falling on your bike but not the other way, bike fall on you and you look like the grandfather of all idiots plus you go to hospital with broken parts. And yeah, for the guy that talked about Canada, I'll take my healthcare here stateside.
Sorry, for the jumping in but I had to post up.
Carry on.

[saxjonz]

Originally Posted by akima

@Jiggles: you're such a troll!



I just ordered a pair of Diablo Rosso 2's

By the way I never dropped the bike so it's not that big a deal to handle with a calm but concentrated effort.

[saxjonz]

Here for you to peruse in your free time. Just thought you'd like to hear what other "motorcyclists" have to say about your get off. Not normal cagers who have no clue.
http://www.zrxoa.org/forums/showthre...-leaving-house

[Alex]

Link to ZRX site fails for anyone who doesn't have an account on that forum.

[Jiggles]

I registered and I still can't access it haha

[nsaP]

So how fast were you really going dude...my guess was 33-35 based on revs and shifts.

[Jiggles]

Originally Posted by nsaP

So how fast were you really going dude...my guess was 33-35 based on revs and shifts.

You are only 5-7 off lol

[nsaP]

Nah dude no way you were doing 40

Just lookin for the truth...you wouldn't have blacked the speedo if you didn't have to worry about it

If I was gonna be a dick I'd comment on your braking reflexes.

[Jiggles]

I was going 28, it's blocked out because if the insurance company could see the actual speed they could split the fault, i.e. Jiggles is X over the speed limit so he is Y% at fault.

And you can comment on my braking reflexes if you want but that's not what I was initally trying to do. My first reaction was get off throttle, hand on brake, go around her, then she kept coming and when I saw that she kept coming that's when I tried to brake

[Heed]

lol @ the elites pulling out the math equations. Hindsight is always 20/20, and this is really good footage excluding the fact that you blocked out the speedo. don't do that next time, even if the insurance company dinks you for it, because it just looks bad IMO. I'd probably ride a little slower in an area like that, have my hand over the clutch maybe. You can't knock him for going 28 in a 25, that's a bit rough. It might be better if the speed limit in that area was lower though? idk. can't believe that witch asked you if you saw her.

[Jiggles]

What looks bad about the speedo? The actual title over it?

[rmorse]

Originally Posted by Heed

lol @ the elites pulling out the math equations. Hindsight is always 20/20, and this is really good footage excluding the fact that you blocked out the speedo. don't do that next time, even if the insurance company dinks you for it, because it just looks bad IMO. I'd probably ride a little slower in an area like that, have my hand over the clutch maybe. You can't knock him for going 28 in a 25, that's a bit rough. It might be better if the speed limit in that area was lower though? idk. can't believe that witch asked you if you saw her.

Actually, you can knock someone for doing 28 in a 25, if the 28 is too high for the conditions. Should I do a video of me lane-splitting at 55, in a 55 zone, where every car is doing 0? I mean, I'm doing the speed limit, right?


Jiggles - It sucks you got hit. It really does. You were also going too fast for the conditions. You should have been doing closer to 20 MPH indicated. You mentioned earlier in the thread that noone goes that slow. I was *sorta* with you when you said that, because it does seem too slow. Well, guess what? EVERY day, I ride past the exact same conditions on my way to work. I did 28 MPH INDICATED to re-create your scenario a bit. And I felt like I was going way too fast; I felt like I would not be able to react in time if one of the parked cars pulled out. The next day, I rode at what I felt comfortable at (and what I felt like was a safe-enough speed so I could react if a driver does something stupid) and glanced down at my speedo.....I was at about 18 MPH indicated.



My above post is pointless. You continue to claim that noone knows what they're talking about, you weren't going too fast, it was 100% unavoidable, blah blah blah. Even when riders with years and 100k of miles of experience say you were going too fast, you tell them they are wrong. So, it's pointless. You won't learn, you'll try and push yourself past that lump in your throat the next time you get caught in that situation, and you (hopefully not) might crash again in a similar situation. Keep that camera rolling.

[dubojr1]

Originally Posted by rmorse

Actually, you can knock someone for doing 28 in a 25, if the 28 is too high for the conditions. Should I do a video of me lane-splitting at 55, in a 55 zone, where every car is doing 0? I mean, I'm doing the speed limit, right?


Jiggles - It sucks you got hit. It really does. You were also going too fast for the conditions. You should have been doing closer to 20 MPH indicated. You mentioned earlier in the thread that noone goes that slow. I was *sorta* with you when you said that, because it does seem too slow. Well, guess what? EVERY day, I ride past the exact same conditions on my way to work. I did 28 MPH INDICATED to re-create your scenario a bit. And I felt like I was going way too fast; I felt like I would not be able to react in time if one of the parked cars pulled out. The next day, I rode at what I felt comfortable at (and what I felt like was a safe-enough speed so I could react if a driver does something stupid) and glanced down at my speedo.....I was at about 18 MPH indicated.



My above post is pointless. You continue to claim that noone knows what they're talking about, you weren't going too fast, it was 100% unavoidable, blah blah blah. Even when riders with years and 100k of miles of experience say you were going too fast, you tell them they are wrong. So, it's pointless. You won't learn, you'll try and push yourself past that lump in your throat the next time you get caught in that situation, and you (hopefully not) might crash again in a similar situation. Keep that camera rolling.

He'll NEVER post his second crash...

[Jiggles]

Originally Posted by dubojr1

He'll NEVER post his second crash...

That's cuz I'm quitting!