Kawasaki Concours Forum
The C-14, aka Kawasaki Concours-14, the new one :) => The Bike - C14/GTR 1400 => Topic started by: tomp on November 20, 2014, 08:38:53 PM
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Mmm. ABS is not linked. The brakes are linked. The ABS doesn't activate until wheel lock up is detected.
Anyone if ABS front and rear brakes are actually linked, or independent when activated. With BMW's and some others, you can turn off ABS as a single system, but not front or rear separately. Just wondering, but I did understand what gPink was wanting, in unlinking the front/ rear braking system... tp
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Don't have abs or linked brakes. Just a comment on the internet protest post back up the page.
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Don't have abs or linked brakes. Just a comment on the internet protest post back up the page.
Yep, mine doesn't either, but am still curious about whether the ABS system is F/R linked or independent...
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I assumed the linking and ABS was tied together. I know the 08/09 abs was not linked. I wonder if the abs ecu part #s are different.
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Yep, mine doesn't either, but am still curious about whether the ABS system is F/R linked or independent...
I believe it said it is still linked, but toned down a bit because of complaints.
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I assumed the linking and ABS was tied together.
You assumed correct. The ABS module is where the linking takes place.
I know the 08/09 abs was not linked. I wonder if the abs ecu part #s are different.
Yes, different. The 2010-up bikes have extra ports and lines due to the linked portion of the ABS module.
I can't remember all of the specifics, but I did look into all of way back when I wanted to disable my linked brakes. My memory is gettin' fuzzy now.
Rem
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Someone on here did unlink their brakes I thought.
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I've read of some BMW owners doing the same procedure, especially on the 1150 RT with the wizzy brake system. Linked and servo assisted, they actually work too well. Put you over the windshield. I know mine will, if using more than one finger on the lever, or step on the rear brake, forgetting it is linked.
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Someone on here did unlink their brakes I thought.
it involves losing the ABS function on your rear brake. Basically run a line straight from the MC to the Caliper, and plug a couple other lines. That's the only way we've found thus far.
The Brake module is computer controlled and brakes are UNLINKED below 12 MPH, so if we can get the brake module to constantly think its under 12 MPH, winner winner chicken dinner.
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You assumed correct. The ABS module is where the linking takes place.
Yes, different. The 2010-up bikes have extra ports and lines due to the linked portion of the ABS module.
I can't remember all of the specifics, but I did look into all of way back when I wanted to disable my linked brakes. My memory is gettin' fuzzy now.
Rem
IMO you guys are confusing liked brakes and ABS. They are two different functions in the braking system.
The linked brakes means that when I apply only front brake I get some rear brake. Not as much as if I apply both.
When I apply rear brake I get some front brake, but not as much as when applying both.
The ABS part of the braking system consists of sensors on each wheel that determine that a wheel has locked up.
When that occurs the braking powers to that wheel is reduced.
I would sure hope the the designers were not stupid enough to reduce braking at both wheels when only one locks up. :o
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IMO you guys are confusing liked brakes and ABS. They are two different functions in the braking system.
The linked brakes means that when I apply only front brake I get some rear brake. Not as much as if I apply both.
When I apply rear brake I get some front brake, but not as much as when applying both.
The ABS part of the braking system consists of sensors on each wheel that determine that a wheel has locked up.
When that occurs the braking powers to that wheel is reduced.
I would sure hope the the designers were not stupid enough to reduce braking at both wheels when only one locks up. :o
Nope, I'm not confusing anything. What I'm saying is, the ABS module and the linked brake mechanism are one in the same device on the C14...they are combined, controlled, and powered from one place under your seat/tank.
The ABS is combined....same as in your car. Your car has linked brakes already;). What you have is a servo operated valve that releases and re-applies pressure as per braking requirements...to keep the wheels from locking up. If you guys can show me proof that the C14 utilizes independent front and rear wheel ABS, then I'm all ears. I'm not even sure why you'd want independent ABS, but again, I'm open to new ideas if anybody wants to explain them to me;).
Rem
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Yep, what Cory said.
Also, I believe the C-14 is still the only bike that has linked brakes that un-link 'on the fly', and that is a totally digitally controlled thing as opposed to pure hydraulics. I believe the C-14 linked brakes unlink at 12 MPH (or close to that) so that the rear brake can be used on soft ground without engaging the front (both brakes are unlinked of course, but who ever wanted to use the front brake on beach sand?). At 12 MPH they link and stay that way until the vehicle is again below that speed. So there is a baby ECU on board the ABS units on the later bikes.
It <may> be possible to swap the ABS pump on a Gen. 2 C-14 for a Gen. 1 pump, still have ABS but no longer have linked brakes. It would take re- plumbing of the front brakes at the very least. And I am not sure what else may or may not need to be modified but it should be possible.
Brian
Nope, I'm not confusing anything. What I'm saying is, the ABS module and the linked brake mechanism are one in the same device on the C14...they are combined, controlled, and powered from one place under your seat/tank.
The ABS is combined....same as in your car. Your car has linked brakes already;). What you have is a servo operated valve that releases and re-applies pressure as per braking requirements...to keep the wheels from locking up. If you guys can show me proof that the C14 utilizes independent front and rear wheel ABS, then I'm all ears. I'm not even sure why you'd want independent ABS, but again, I'm open to new ideas if anybody wants to explain them to me;).
Rem
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Nope, I'm not confusing anything. What I'm saying is, the ABS module and the linked brake mechanism are one in the same device on the C14...they are combined, controlled, and powered from one place under your seat/tank.
The ABS is combined....same as in your car. Your car has linked brakes already;). What you have is a servo operated valve that releases and re-applies pressure as per braking requirements...to keep the wheels from locking up. If you guys can show me proof that the C14 utilizes independent front and rear wheel ABS, then I'm all ears. I'm not even sure why you'd want independent ABS, but again, I'm open to new ideas if anybody wants to explain them to me;).
Rem
They are controlled from the same module but that doesn't mean that the antilock brake algorithms are the same as the linked brake algorithms. The bike has a front brake reservoir and a rear brake reservoir. The ABS can definitely work independent, because the wheels can lock up independently.
When you are manually braking the bike and the rear locks up, you are not going to let go of both brakes. You are going to modulate the rear brake and continue pressure on the front brake.
But, what it sounds like is that we are both making assumptions. You are assuming linked brakes means linked Antilock Braking System. I am assuming that linked brakes and Antilock Braking System are two different features of the Brakes on the Concours.
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Here is a Kawasaki video explaining ABS. It shows how the control unit senses wheel lockup at each wheel and modulates the braking at that wheel.
Kawasaki Motorcycles: Anti-Lock Brake Systems (ABS) (http://www.youtube.com/watch?v=BBhxjIkRFCw#ws)
Here is an explanation of K-ACT, but not the ABS function (or what happens when wheel lockup is sensed)
Kawasaki K-ACT (http://www.youtube.com/watch?v=nRqSTkwQRMM#)
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Here is a Kawasaki video explaining ABS. It shows how the control unit senses wheel lockup at each wheel and modulates the braking at that wheel.
Kawasaki Motorcycles: Anti-Lock Brake Systems (ABS) (http://www.youtube.com/watch?v=BBhxjIkRFCw#ws)
Here is an explanation of K-ACT, but not the ABS function (or what happens when wheel lockup is sensed)
Kawasaki K-ACT (http://www.youtube.com/watch?v=nRqSTkwQRMM#)
I have found verbiage that states that K-ACT complements the standard ABS.
So, since the point is to provide optimum braking force without locking the wheels up, it makes sense that if the system senses wheel lock in only the front wheel, it would only modulate the front brakes to maintain maximum braking force.
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They are controlled from the same module but that doesn't mean that the antilock brake algorithms are the same as the linked brake algorithms. The bike has a front brake reservoir and a rear brake reservoir. The ABS can definitely work independent, because the wheels can lock up independently.
When you are manually braking the bike and the rear locks up, you are not going to let go of both brakes. You are going to modulate the rear brake and continue pressure on the front brake.
But, what it sounds like is that we are both making assumptions. You are assuming linked brakes means linked Antilock Braking System. I am assuming that linked brakes and Antilock Braking System are two different features of the Brakes on the Concours.
Yup...we are both making assumptions...lol. I just know that the brakes are linked and I've never heard anything about them becoming unlinked during an ABS 'incident' until now. But that's totally fine...I'm always open to learning new things.
I've done some pretty aggressive braking on my C14, and while I've never locked a wheel up, I can certainly feel the linking activity taking place (and the ABS). It never occurred to me that the ABS would work independently between the front and rear on a 2nd gen C14.
I don't know how the ABS/Linked module could modulate the pressure independently when the pressures are already linked and constantly affecting each other. If the ABS module is unlinking the brakes during an ABS interaction, and then doing separate calculations on both front and rear wheel speeds, then the ABS module is far more complex a device than I thought it was.
I was going to buy a used ABS module a while back and take it apart in an effort to better understand how it worked and to find a way to unlink my brakes electrically, but the linking never annoyed me enough to spend the money to do it...lol.
Rem
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Just read an article on the BMW ABS system, and it was noted that applying the front brake lever in an emergency situation activates both front and rear ABS simultaneously. Didn't say what applying only the rear to lock up did. Would go try my RT tomorrow to find out, but suppose to rain all day.
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I can do that on my 08 at half the price although it's somewhat manual in nature.
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I have found verbiage that states that K-ACT complements the standard ABS.
So, since the point is to provide optimum braking force without locking the wheels up, it makes sense that if the system senses wheel lock in only the front wheel, it would only modulate the front brakes to maintain maximum braking force.
Hehe...yes, you are absolutely correct...but in the video and verbiage, the independent front and rear ABS activity pointed out are on the models that do not have linked brakes, like the ZX10R. When the video gets to the Concours-14, it says that the K-Act ABS module synchronizes all front and rear braking activity...it doesn't mention anything about the ABS acting independently on the front and rear wheels.
On models that have completely separate front and rear brakes, then yes, absolutely, the ABS will work independently.
Don't worry, I'm not saying that you're wrong...since I obviously don't have any evidence to the contrary. The 08-09 C14 models with ABS would have independent ABS actions for sure. If the 2nd gen linked brake models are doing this, then they would definitely have to unlink the brakes at that time, and I've never heard of that before today, that's all;).
Rem
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Just read an article on the BMW ABS system, and it was noted that applying the front brake lever in an emergency situation activates both front and rear ABS simultaneously.
Well, if that bike has a linked braking system, then that would make sense to me. I don't know poop about BMW's though, so I can't comment really...other than I understand the concept.
Rem
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I don't know how it works either but your assumption here makes logical sense: if both brakes were applied by the rider such that, say, the rear brake began to lock up, the ABS system would modulate only the rear brake to stop it from locking while leaving the front brake alone (and under the same [not yet to lock] braking force already being applied). Which effectively amounts to 'unlinking' the linked brakes.... sort of. But that would require two separate modulator pumps in the ABS module. ??
Interesting discussion and topic either way though.
Brian
I have found verbiage that states that K-ACT complements the standard ABS.
So, since the point is to provide optimum braking force without locking the wheels up, it makes sense that if the system senses wheel lock in only the front wheel, it would only modulate the front brakes to maintain maximum braking force.
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Well, if that bike has a linked braking system, then that would make sense to me. I don't know poop about BMW's though, so I can't comment really...other than I understand the concept.
Rem
The article was on a model with semi linked brakes. Front applies both, and rear, only the rear, but the ABS is applied to both with the front lever. My 04 has fully linked; front or rear apply both equally, and can scare the crap out of you if you get on the rear too hard.
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Just read an article on the BMW ABS system, and it was noted that applying the front brake lever in an emergency situation activates both front and rear ABS simultaneously. Didn't say what applying only the rear to lock up did. Would go try my RT tomorrow to find out, but suppose to rain all day.
In a straight line on wet pavement would be the preferred way to exercise ABS. I'm not yet familiar enough with the ABS systems on motorcycles to have an intelligent opinion as to the need to "exercise" the system. 25 years ago the automotive systems needed to be activated or "exercised" periodically to keep the valves from sticking due to non use. After several years the manufacturers realized that in order to minimize the sticking valve problems, a simple momentary activation upon start up eliminated the vast majority of their ABS related warranty claims.
We used to tell customers to go ahead and try the ABS in a wide open space (i.e. parking lot) to activate the system and to experience what it felt like when it was used
W
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In a straight line on wet pavement would be the preferred way to exercise ABS. I'm not yet familiar enough with the ABS systems on motorcycles to have an intelligent opinion as to the need to "exercise" the system. 25 years ago the automotive systems needed to be activated or "exercised" periodically to keep the valves from sticking due to non use. After several years the manufacturers realized that in order to minimize the sticking valve problems, a simple momentary activation upon start up eliminated the vast majority of their ABS related warranty claims.
We used to tell customers to go ahead and try the ABS in a wide open space (i.e. parking lot) to activate the system and to experience what it felt like when it was used
W
That is excellent advice especially on two wheels. A rider should be familiar with all the electronic systems that affect handling. Since I have neither abs nor traction control I'm left with practicing activating the rev limiter. :)
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I don't know how it works either but your assumption here makes logical sense: if both brakes were applied by the rider such that, say, the rear brake began to lock up, the ABS system would modulate only the rear brake to stop it from locking while leaving the front brake alone (and under the same [not yet to lock] braking force already being applied). Which effectively amounts to 'unlinking' the linked brakes.... sort of. But that would require two separate modulator pumps in the ABS module. ??
Interesting discussion and topic either way though.
Brian
I think between the videos I posted and articles I have read that I have a pretty good understanding how the K-ACT ABS system works. The ECU and control loop software are in control of what is happening when you brake and when the system determines front or rear wheel lock up. The goal of the system is to keep the braking force between the front and rear brakes balanced to provide maximum stopping power so that you don't reach the point of causing wheel lock up as soon as you would on a non K-ACT bike.
The computer monitors the amount of braking pressure applied to either the front or rear brakes individually and applies the calculated solution force to the opposite brake, or when both brakes are applied the computer adjusts the pressure going to each brake to maintain the optimum balance point for braking.
Knowing that the computer can modulate the pressure in EACH circuit (front or back) then it certainly can modulate the braking pressure to only the wheel that is experiencing lock up.
The brakes are always linked, but are individually modulated by the computer based on the inputs it receives.
The inputs are:
1. front brake fluid pressure caused by the rider pulling in on the front brake lever.
2. rear brake fluid pressure caused by the rider pushing the rear brake lever.
3. rear wheel sensor
4. front wheel sensor.
5. motorcycle speed.
6. there may be others but I have not discerned any additional information from what I have read.
These inputs go into the calculated solution to determine how to distribute the fluid pressure going to both the front and rear brakes.
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The brakes are always linked, but are individually modulated by the computer based on the inputs it receives.
And also the linked setting the user chooses (high or low).
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I think between the videos I posted and articles I have read that I have a pretty good understanding how the K-ACT ABS system works. The ECU and control loop software are in control of what is happening when you brake and when the system determines front or rear wheel lock up. The goal of the system is to keep the braking force between the front and rear brakes balanced to provide maximum stopping power so that you don't reach the point of causing wheel lock up as soon as you would on a non K-ACT bike.
The computer monitors the amount of braking pressure applied to either the front or rear brakes individually and applies the calculated solution force to the opposite brake, or when both brakes are applied the computer adjusts the pressure going to each brake to maintain the optimum balance point for braking.
Knowing that the computer can modulate the pressure in EACH circuit (front or back) then it certainly can modulate the braking pressure to only the wheel that is experiencing lock up.
The brakes are always linked, but are individually modulated by the computer based on the inputs it receives.
The inputs are:
1. front brake fluid pressure caused by the rider pulling in on the front brake lever.
2. rear brake fluid pressure caused by the rider pushing the rear brake lever.
3. rear wheel sensor
4. front wheel sensor.
5. motorcycle speed.
6. there may be others but I have not discerned any additional information from what I have read.
These inputs go into the calculated solution to determine how to distribute the fluid pressure going to both the front and rear brakes.
I'm with ya, the system likely does work the way you describe.
I wasn't really thinking of the locking up of the rear wheel affecting the front ABS...I didn't put much though into that, but no, you certainly wouldn't want that to happen imho. However, when considering heavy front braking....I would want my front and rear ABS to work together.
Keep in mind the ABS will become active long before the wheel actually locks up...even if we're only talking about milliseconds here, but still...the point isn't for the ABS system to sense a wheel locking up before it activates.
Under heavy front braking...and I mean not even touching the rear brake at all...you're still activating both brakes, and the bike knows you're in a panic situation. It would make sense to me if the ABS were activated on both wheels...they're both turning the same speed, and they're both in a situation where the ECU is sensing they may lock up. Now, even though the rear brake is activated via the front, it's still under a lighter pressure than the front...BUT, as the front dives and the rear of the bike becomes raised/lighter, the back wheel can lock up much easier with much less pressure. This is why vehicles used to have those mechanical brake proportioning valves.
Anyway, just food for thought is all. It would seem logical to me if there's an "ABS calculation" involved that activates both wheels under single front brake activation (when both brakes are actually activated).
That's all, nothing more. In my little mind, that's how I would want it to work. It would be the same as Tomp mentioned above about the BMW...that activating only the front brake operates the ABS on both wheels. There are likely calculations to make the ABS system work both ways...depending on the situation;).
At the end of the day, I have no idea...lol.
Rem 8)
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This is all very interesting. Even though it is one "system" that controls the two functions- linking and ABS, I never quite thought of how the two might work together, especially in lockup situations where the ABS kicks in. It is too bad the manuals don't have any theory info about how the two work together. The owner's manual says little other than very generic stuff. In the service manual, although there is a lot of info about troubleshooting and repair of the ABS system, it says nothing about how it actually works and no mention at all about linked brakes, other than the indicator and the switch for mode selection.
Having looked through the whole service manual on the topic and comparing the old (Gen 1) ABS system to the newer (Gen 2) ABS system (which they renamed "K-ACT" which is "Kawasaki Advanced Coactive-braking Technology"), it is apparent they added additional functionality for connectivity to the ABS system through CAN (Controller Area Network) communication lines (missing on Gen 1). This does hold out a little (although probably not much) hope that it might be programmable. The line is more likely just for the ABS computer to talk to the main computer to share data and/or for service.
Also of interest, while the Gen 1 ABS system has a primitive method of relaying trouble codes via shorting a connector and dealing with counting the flashing ABS light, the Gen 2 system will just display the codes directly on the main LCD display.... although it is very unclear from the manual (12-32 through 12-40) how to trigger it to do so or if it is automatic. It might require connection to some type of Kawasaki service computer.
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WOW, this is getting more confusing by the post. Being handled by some form of computer, I guess it works with lightening speed and amazing accuracy, at least that's what a computer genius friend once told me. He is now dead, but I believe his thoughts were correct. RIP, Charles...