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Discussion Starter #1
Even I don't drive or ride extremely hard I like to test my machines at the limit just to know what to expect. I was surprised how the brakes behaves. I have the new 2008 with non assisted brakes. What is happening is that if brakes are progressively applied braking is good enough, not very firm though. If on good road surface and suddenly apply full force brake, as recommended in case of emergency actually ABS came in and prevent from braking, you feel it making click- click- click and keep going and going. Pretty scary. Road was best quality, absolutelly no slipping. Same non assisted brakes are doing a very good job on the GS1200Adv., lifting rear wheel in the air few cm before the ABS is coming in. I may be wrong but if I remember correctly the old assisted brakes on 2006 model worked better. Did yo test your ABS?
 

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Doru,

Yes. I tested my 2007 K1200GT against many other brands of motorcycles. Everyone rode toward a line marked with two cones, then applied the brakes to practice emergency stops. Speeds started out at 20 mph (32 kph) and were increased to 40 mph (64 kph).

My K1200GT did the best. I felt the brakes shudder as I grabbed them hard and held them. The shuddering didn't last long, because the bike stopped very quickly.

The surface was moderately rough asphalt (blacktop).
 

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Testing ABS

I'm not sure what you mean by "non-assisted brakes", I thought all next gen GTs (06+) had the same braking system.

Anyway, I also tested my ABS a lot when I first got the bike, and do so every now and then still. I did hard braking front only, rear only, and combined on gravel, dirt, and dry and wet asphalt.

IMHO the ABS on the KGT is superb. It always did exactly what I expected. I still routinely feel the ABS kick in on the back because I seem to have developed a habit of over-braking on the rear (especially while downshifting), but that's minor and the ABS is helping me kick that habit.

I find it a little surprising when the front ABS does kick in, mainly because I'm slowing down so damn fast by then! The bike stops really quickly, faster than I typically anticipate. That is, I always expect the ABS to kick in sooner. I actually find it very comforting to know that I can literally just squeeze the hell out of the front lever and stop quickly and safely.
 

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07 and 08 GTs have Teva non-servo assist brakes. 06 GTs use the servo assist version.
 

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Doru, I have a late 06 and when I emergency brake my ABS completely fail and my large stomach undulates all over the tank.
My trainer has said if I cut down on the beer and do 100 sit ups a day my ABS will come back and that I wont have this braking problem.
P.S. Sorry, its Friday night and I am on my 3rd glass of red and couldnt resist.
Only the early 06`s had power assistance. By November 06 it had been removed as many found it too sensitive. I have read a number of forums that were critical of the GT ABS for the exact reason that you state however this new feel apparently allows you to still steer the bike at fairly accute angles under heavy braking where as the earlier ABS as on your GS still chirps and would lose traction if steered quickly with a handful of lever.
 

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Discussion Starter #7
man, when a tractor pull brakes out of the sudden in front of you like it happened to me all you need is to stop. well you can't stop with this one. i just want to know if "they all do that" or have to take it to the doctor. enjoy your red. here 2pm, still at the office.
 

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Doru,

Are you talking about actually not stopping or the feeling that you are not stopping because the ABS is reducing braking power? In the latter case the vehicle actually does stop quickly but feels like you could get more braking power without the ABS.

The only experience I have had with the ABS on the bike is with the rear brakes. A few times I have deliberately tried to lock up the rear wheel at slow speeds on a slippery surface, such as sand on smooth bitumen. In this case the ABS reduced braking power to almost zero as soon as it locked up due to the lack of grip available and I am sure I could get more braking by manually controlling the brakes. Maybe this is what happened to you and the surface didn't have as much grip as you thought.

I have never even come close to locking the front brake in any conditions and I ride every day of the year. I have done several very heavy stops and the only ABS the kicked in slightly was the rear, usually because of the extra engine braking due to downshifting in a hurry.

I have had an experience a bit like you have described in my Volvo 850. In this case I think my brain went missing and I was accelerating straight for pedestrians crossing the road in the middle of the city when I suddenly realised what was happening and hit the brakes. The ABS took over and I felt like the car wasn't stopping. However, it did stop about 1m from the crowded pedestrian crossing. It is disconcerting when no matter how hard you apply the brakes you don't get any more braking power and this is what ABS does to cars and bikes. I think it is mostly a feeling rather than an actual significant drop in braking capacity, especially on good surfaces.
 

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Discussion Starter #9
BobD said:
Doru,

Are you talking about actually not stopping or the feeling that you are not stopping because the ABS is reducing braking power? In the latter case the vehicle actually does stop quickly but feels like you could get more braking power without the ABS.
what i was saying is that pulling brake to the bottom as recommended in case of emergency makes breaks weaker than if using them progressivelly. a different bike, gs1200adv with exactly same breaks lift the rear wheel before entering abs, this one is not stoping, abs is entering too early.
 

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I Have an 07 GT, 03 FZ1 (Yamaha Fazer 1000 in Europe), 00 Ducati, I ride the same route to work every day, altering the bikes. The only time I can really tell a difference in hard braking is when it is wet, with the BMW its just brake, the others you have to pay attention to lever pressure.

I think you need to try another GT to compare to yours. It sounds like the ABS software is not correct in your bike. (After all the iterations of the engine management software, I would expect maybe some bits are confused in the braking computer) A comparision between bikes should answer that question.
 

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Brakes

Doru-in-Romania said:
i'm talking about new 2008 non assisted brakes, i remember 2006 were fine. anybody tested non assisted brakes?
I've got an '07 GT, so non-assisted brakes. What you describe is definitely different from what I experience -- I've never experienced my GT not stopping fast enough for me! ...good thing the first service is only 600 miles, ask the dealer to check it out.
 

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Doru-in-Romania said:
i'm talking about new 2008 non assisted brakes, i remember 2006 were fine. anybody tested non assisted brakes?
Yes. The tests that I described above were done on a 2007 K1200GT with non-servo brakes and ABS.

The bike stopped very quickly. The braking force was very strong. It took arm strength and a good grip with knees and thighs to keep from sliding forward during maximum braking.
 

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BobD said:
The only experience I have had with the ABS on the bike is with the rear brakes. A few times I have deliberately tried to lock up the rear wheel at slow speeds on a slippery surface, such as sand on smooth bitumen. In this case the ABS reduced braking power to almost zero as soon as it locked up due to the lack of grip available and I am sure I could get more braking by manually controlling the brakes.
No, actually, you couldn't. :)

ABS simply measures the rate of wheel spin. When it kicks in, it's because the wheel has stopped rotating, i.e. you are in an imminent skid. So ABS pumps the brakes for you, resulting in maximum effective braking for the exact conditions encountered without locking up the wheels.

Without ABS, you would simply lock a wheel. If that's the rear and you're skilled enough to control the slide without crashing then maybe you could stop just a bit quicker. If it's the front wheel however, you're pretty much guaranteed to go down, hard. And plastic sliding along the pavement has a much lower coefficient of friction than rubber so he bike will just keep sliding until it hits something. :)

So yes, the ABS sometimes feels like you're not stopping as fast or that you're actually speeding up a bit, when in fact it's just the brief pulsing sensation that you're feeling. Think of it as going from 100% braking efficiency, down to 50%, then back to 100%. The brakes are applied and braking the whole time, but the 50% cycles feel like you're speeding up some when in fact you're still stopping, just not quite as fast.

And yes, stopping a bike with ABS engaged will take slightly longer than stopping at just the limit of traction right before the ABS kicks in, but there are probably only about 1/10th of 1% of professional riders who can reliably and repeatedly hit that point.

For the rest of us mortals riding in highly uncontrolled street situations, ABS allows us to nail the brakes hard in a panic situation while maintaining control even while we're over-braking for the conditions.

So in a true panic stop, if you're not activating ABS on both wheels then you're not braking the front hard enough, and thus you're actually taking longer to stop than you should. And if you're activating the rear ABS in merely aggressive riding then again, you're not using the front brake enough. And if you are activating ABS on both wheels in anything other than a full-on panic stop, then you're seriously outriding the conditions and you will eventually pay for it.
 

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Well, rarely, you could

Meese said:
No, actually, you couldn't. :)
Well, rarely, you could. :teeth

In the conditions he described (almost no traction to begin with) locking the wheel might actually have provided more braking power (along with a complete lack of control) than not locking it.

ABS is a good thing mainly because the coefficient of sliding friction is typically less than that of static friction for the wheel against the ground. As these both approach zero, they approach each other and so ABS or not doesn't matter. (...because you're not getting much stopping power either way.)

Now if you think about really bad surfaces (snow, wet leaves, loose gravel) you might actually stop faster if you lock the wheel because you'll "push through" the crappy surface and maybe get the wheel in touch with something underneath that offers some traction. But on the other hand you might only make it worse, I had a lady hit my car from behind because she locked her brakes on some wet pine needles, then pushed the mass of slippery crap forward onto the dry pavement and kept sliding on it. ABS would have let her stop normally once she got out of the slippery patch.

So I agree that ABS will beat no-ABS any time where it would actually matter. (But I like to argue.)
 

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grifscoots said:
Unless you're on washboarded caliche!
Well sure, when your wheels are actually airborne then the coefficient of friction is zero. :D
 

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bonafidebob said:
So I agree that ABS will beat no-ABS any time where it would actually matter.
And that's the point. For most folks most of the time, in a full-on panic stop ABS will help keep you from crashing. And that's a good thing.

bonafidebob said:
(But I like to argue.)
Really? Who knew? :D
 

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Meese said:
And that's the point. For most folks most of the time, in a full-on panic stop ABS will help keep you from crashing. And that's a good thing.
My biggest problem was relearning memory to use the ABS. I had ridden longer without it and in a panic situation was trying to modulate the brakes myself.

In ERC's or playing in parking lots where I consciously was trying to use ABS, I could. When in a panic, I fell back to modulating.

I THINK, after 128,000 BMW miles I'm starting to just nail them when needed.
 

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grifscoots said:
I THINK, after 128,000 BMW miles I'm starting to just nail them when needed.
You gotta learn to trust the technology, but keep your own skills sharp. BMW makes some awesome bikes, despite their faults. :)
 

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Meese said:
No, actually, you couldn't. :)

ABS simply measures the rate of wheel spin. When it kicks in, it's because the wheel has stopped rotating, i.e. you are in an imminent skid. So ABS pumps the brakes for you, resulting in maximum effective braking for the exact conditions encountered without locking up the wheels.
I agree with most of what you said but in the conditions I was talking about if I didn't have ABS I would not let the back wheel lock up and I reckon I would get more braking because of the big reduction in braking power as soon as grip is lost by hitting the brakes hard on such a slippery surface. What I was talking about is a deliberate test to see how the ABS works on very poor surfaces at slow speeds where I can easily control a rear wheen slide. In normal riding I am like others and ride so I don't need to go anywhere near the point of losing traction after many decades of riding bikes without a crash.

Nice to know that the ABS is there for a real emergency however, even if I have never actually had one yet.

On second thoughts I did need it the other day. I tuned off a highway into a reservoir access road late in the afternoon in thick forest with my 14 year old son on the back, accelerated to 40mph. The road was steeply sloping down hill and winding with continuous sharp corners. As soon as I hit 40 I almost panicked. There was almost no grip as it had just been resealed and was covered in an inch or so of loose blue metal (crushed granite) with no previous traffic over it and unswept.

I didn't dare to use the front brake and with engine braking and light rear brake I tried to reduce speed down the steep hill. We had one big rear wheel slide, probably engine braking that ABS can do nothing about and managed to turn a couple of the corners while sliding everywhere until I managed reduce speed enough to match the grip available. My heart was beating fast but I didn't fall off.

Maybe I should have used the front and let the ABS help out but I don't think so as I was on the limit of traction just trying to turn the corners and any extra forces would have tipped it over the edge literally.
 
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