Emergency Brake study

[cougar8000]

https://www.msf-usa.org/imsc/proceedings/a2...kingSystems.pdf

 

[uctofeej]

Interesting find, Cougar.

If I've understood it correctly and assuming the computer doesn't declutch right away, an AE rider could be looking at almost 10 feet longer in an emergency brake situation than an A model rider who pulls the clutch lever at the start of the braking process. Hmm.

 

[Rickster]

Interesting read, but I don't see how you get 10 feet.

Page 9 the 100Km/H to 0 tests:

Clutch engaged = 41.51 meters average 35 tests

Clutch disengaged = 39.95 meters average 11 tests

41.51 - 39.95 = 1.56 meters = 5.11811024 feet (approximately)

And this would assume that the clutch remained engaged the entire stopping distance. and on page 10 the report indicated that over the group of 298 tests the mean braking distance (100 km/h to 0) was 41.7072 meters (i.e. longer than the clutch engaged 35 test sample by .1972 m)

 

[uctofeej]

Ah, I see. I was going by the page 12 figures using the optimal sequence (see table 4) and comparing to the 172 tests:

This table represents the 30 tests with the shortest stopping distance and during which riders cut the throttle,used the two brakes and pulled the clutch lever at the start of braking instead of at the point of the motorcycle

reaching a standstill.

I came up with the difference between the optimal group (38.35 meters) and the mean (41.81 meters), which is actually more like 11.35 feet. Regardless of the actual number, the clutch disengagement point may mean the difference of a few feet.

 

[cougar8000]

Interesting find, Cougar.
If I've understood it correctly and assuming the computer doesn't declutch right away, an AE rider could be looking at almost 10 feet longer in an emergency brake situation than an A model rider who pulls the clutch lever at the start of the braking process. Hmm.

Glad you like it. Can't really take credit for it. I maintain a safety section on another forum and people find me stuff all the time. Think of me as a safety pimp :yahoo:

All this years teaching I was teaching to apply all four at the same time to make a memory muscle. Now I have even better reason to pass on to the students.

Memory muscle is what it is all about.

 

[MEM]

Interesting find, Cougar.
If I've understood it correctly and assuming the computer doesn't declutch right away, an AE rider could be looking at almost 10 feet longer in an emergency brake situation than an A model rider who pulls the clutch lever at the start of the braking process. Hmm.

Glad you like it. Can't really take credit for it. I maintain a safety section on another forum and people find me stuff all the time. Think of me as a safety pimp :yahoo:

All this years teaching I was teaching to apply all four at the same time to make a memory muscle. Now I have even better reason to pass on to the students.

Memory muscle is what it is all about.

Hi Alex

Thank you for posting this study . I'm taking an ERC the end of this month and I'm thinking I might do some practising beforehand. My cousin is an MS instructor, a big fan of my FJR - he rides a BMW and 2 Ducatis - and he's my own personal instructor on occasion ;-) I'm really concerned about dropping my bike during this course. May The Force be with me .... :assassin: (I should be practising the dropped bike pick-up, too!)

 

[El Toro]

Its an interesting read. Thanks for posting it.

One might tend to extrapolate from these two motorcycles, with these specific tires, these specific braking systems, on this specific pavement, with these specific riders, to draw general conclusions about stuff like clutching vs. non clutching, shifting vs. non shifting, etc. I don't think the data are sufficiently complete to draw general conclusions that could be extrapolated to the general population of 2 wheeled vehicles.

Probably the most important factors in an emergency stop are staying up and missing the impact. Practice to develop muscle memory can help (including the head muscle). However, with all the different linked brake strategies out there (Honda seems to like to actuate linkage through both front and back, the FJR is linked only through the rear, my BMW K1200Rsport is only linked through the front), various forms of ABS (again, the algorithms and mechanical strategies vary from marque to marque), tire choices (including the choice to run past your wear bars), pavement conditions, etc., suggest to me that after you've figured out how to keep your own bike up with a good decelleration, time spent concentrating on what could potentially come into the 2 second box in front of you is critical.

I thought the original poster's line at the bottom about using superior strategies to avoid having to use superior skills was excellent advice..... although certainly I recognize that we all want to develop superior skills too.

 

[Spook]

I think most of you miss the point on the use of the clutch or no was with down shifting along with breaking. most of the time if you are in that situation you should be concentrating on getting the bike stopped not down shifting. Another point the computer on an AE will not let you shift down at any point that will allow the back wheel to slide so inherently it should be the more safe if you are down shifting while breaking hard. There did not appear to be any AE's in the test.

 

[charismaticmegafauna]

<snip>... Another point the computer on an AE will not let you shift down at any point that will allow the back wheel to slide so inherently it should be the more safe if you are down shifting while breaking hard. There did not appear to be any AE's in the test.

The article was done in 2004 (there were no 'AEs').

It was done by Moto Journal (the Franco-phone arm of Cycle Canada).

Generally, a good article on maximum braking....I think.

 

[cougar8000]

I think most of you miss the point on the use of the clutch or no was with down shifting along with breaking. most of the time if you are in that situation you should be concentrating on getting the bike stopped not down shifting.

See, that is where you are wrong for the lack of a softer word. And here is why.

I do not think that anyone would try to dispute the fact that riding motorcycle and reacting to different situations is mostly muscle memory. That said. if you train your self to stop properly, i.e all four at the same time as we teach in MSF. Front brake, rear brake, clutch lever and gear shifter. You will always stop in the first gear and shifting down will not make your stopping distance longer.

You will be in the first gear ready to go in case someone behind you is not going to stop in time.

You should never entertain an idea of not down shifting for the sake of something else. That is how bad habits are born.

Consequences of not doing all four is stopping and then not able to get out of the way quickly and getting railed from behind.

Enjoy your ride.

BTW. As far as your comment on AE and shifting while stopping. I think that is what they covered in the article. What they said you should not be releasing the clutch after every shift.

 

[Spook]

I think most of you miss the point on the use of the clutch or no was with down shifting along with breaking. most of the time if you are in that situation you should be concentrating on getting the bike stopped not down shifting.

See, that is where you are wrong for the lack of a softer word. And here is why.

I do not think that anyone would try to dispute the fact that riding motorcycle and reacting to different situations is mostly muscle memory. That said. if you train your self to stop properly, i.e all four at the same time as we teach in MSF. Front brake, rear brake, clutch lever and gear shifter. You will always stop in the first gear and shifting down will not make your stopping distance longer.

You will be in the first gear ready to go in case someone behind you is not going to stop in time.

You should never entertain an idea of not down shifting for the sake of something else. That is how bad habits are born.

Consequences of not doing all four is stopping and then not able to get out of the way quickly and getting railed from behind.

Enjoy your ride.

BTW. As far as your comment on AE and shifting while stopping. I think that is what they covered in the article. What they said you should not be releasing the clutch after every shift.

Thank you for teaching me how to ride. Man I guess I did not learn any thing in 40 years of being on a bike I will bow to your great knowledge. I guess it is critical that you are in first gear when you get stopped why did I not think of that every time I have had to bring it down when a ******* deer ran out in front of me. I will be sure to remember that the next time it happens so I can make a very quick get away.

 

[cougar8000]

You are so damn funny, it hurts.

There is an old russian saying that says something like young and old are all the same. Young riders think they know it all and on the opposite spectrum there are those that say I have been riding before you were even born. What the **** can you teach me sonny.

So, yeah. you are right. Enjoy your ride. There is nothing anyone can teach neither of you.

 

[boomerang]

I think most of you miss the point on the use of the clutch or no was with down shifting along with breaking. most of the time if you are in that situation you should be concentrating on getting the bike stopped not down shifting.

See, that is where you are wrong for the lack of a softer word. And here is why.

I do not think that anyone would try to dispute the fact that riding motorcycle and reacting to different situations is mostly muscle memory. That said. if you train your self to stop properly, i.e all four at the same time as we teach in MSF. Front brake, rear brake, clutch lever and gear shifter. You will always stop in the first gear and shifting down will not make your stopping distance longer.

You will be in the first gear ready to go in case someone behind you is not going to stop in time.

You should never entertain an idea of not down shifting for the sake of something else. That is how bad habits are born.

Consequences of not doing all four is stopping and then not able to get out of the way quickly and getting railed from behind.

Enjoy your ride.

BTW. As far as your comment on AE and shifting while stopping. I think that is what they covered in the article. What they said you should not be releasing the clutch after every shift.

In most emergency stops you are right ( I think ) But in that I've got to stop right now or die moment screw down shifting, I'm grabing every lever, and standing on the break as hard as I can with out sliding.

 

[Crash Cash]

They couldn't have found a smaller data-acquisition computer than a frigging full size Mac G4 on the back?? Jesus H. Christ! Best Buy was out of laptops or something?

I find it interesting that they don't mention a locked rear wheel can highside your ass to the moon if you unlock it while you're slewed to the side. This is why my MSF instructor said "if you lock your rear brake, keep it locked"

Plus this is the first time I've seen that the fastest stop is not necessarily the shortest stop. This is better'n Mythbusters!

 

[LAGO RUNNER]

All I have to say is thank god for ABS. I know of two situations where it kept me from being in a bad wreck. once on BMW 1150 Rt, once in the 08 feej.

 

[cougar8000]

In most emergency stops you are right ( I think ) But in that I've got to stop right now or die moment screw down shifting, I'm grabing every lever, and standing on the break as hard as I can with out sliding.

You can do what ever you decide, but if you practice all four you will be in first when you stop.

It does not matter if you are in the city or a country full of deers. i just spent a week in the country and stoping to avoid a deer is not the only thing to worry about it. there are people right behind you who were doing 60+ just a second ago...

you can train your muscle to do the RIGHT thing all the time, or you can train your self for failure. Choice is yours.

Example. 3 yrs ago friends and I were practicing emergency braking. One decided to practice Stopies. Guess what he did when car pulled in front of him?

 

[Kevin Daly]

They couldn't have found a smaller data-acquisition computer than a frigging full size Mac G4 on the back?? Jesus H. Christ! Best Buy was out of laptops or something?
I find it interesting that they don't mention a locked rear wheel can highside your ass to the moon if you unlock it while you're slewed to the side. This is why my MSF instructor said "if you lock your rear brake, keep it locked"

Plus this is the first time I've seen that the fastest stop is not necessarily the shortest stop. This is better'n Mythbusters!

No doubt they could have used any number of cheap data acquisition systems that would have fit nicely in a pocket for the data they were collecting....Canadians

your right too about the locked rear wheel that takes talent to undo. Sure helps to have some dirt bike experience with that.

But if I read your last comment right, you dont buy that you can make a longer stop in shorter time or a shorter stop with longer time. This is actually easy to understand: acceleration or decceleration can be very nonlinear and just as a loosing dragster can cross the line at a higher top speed than the winning car. so too can a bike stop in less time but coer a greater distance.

Otherwise I thought their method of analyzing their data was dissapointing.

That said I am a firm eliever in practicing maximum breaking; in fact I think I'm going to to to my favorate spot

 

[BwanaDik]

One thing I've noticed while practicing emergency braking on my AE is that it tends to get stuck, or at least stay in the same gear that I was in when I began the braking exercise. If I'm hard on both front and rear brakes, and try to down shift (I use the left pedal, not the finger lever), it stays in the same gear until I stop at which time I can shift it down to first. Anybody else have this problem?

 

[Spook]

One thing I've noticed while practicing emergency braking on my AE is that it tends to get stuck, or at least stay in the same gear that I was in when I began the braking exercise. If I'm hard on both front and rear brakes, and try to down shift (I use the left pedal, not the finger lever), it stays in the same gear until I stop at which time I can shift it down to first. Anybody else have this problem?

no