Here's another thing

[Huzo]

Further to the topic on ABS.
As far as I can tell, all the opinions were expressed and the topic was well covered. I even changed my mind on a couple of long held beliefs, so I'm not out to put anyone's opinion or explanation down.
BUT !!!
IF... The ABS works due to the sensing of differential in the rotational speed of the front wheel versus rear, (with suitable correction for different radii, therefore circumference), what would the ABS do if you were able in some way to hold the wheels on the point of lock (perhaps on grass), by using maximum lever pressure and the wheels managed to rotate at the same rate ?
The ABS would not perceive a potential lock situation so conceivably would not activate ?
Would it not just "think" it was travelling at a slower speed and all was well ?
Even if all that is just BS, how does the system "know" that the wheel has slowed due to locking and not as a result of reduced road velocity ?
What other parameters does it compute ?

[fotoguzzi]

[et18]

I have two thoughts on this:

1.  The dog picture is friggin' awesome in the context of an ABS discussion!

2.  If by point of lock you mean just before the wheel locks, then isn't that basically what ABS does?  Holding the brakes to this point is perfect braking and is beyond my skill level in the real world, at least consistently.  I bought my Beemer in '94 specifically because it had ABS and I've had many instances to appreciate it in the years since.  The ABS (and TCS) on the Cali 1400 are even better.

[Huzo]

I have two thoughts on this:

1.  The dog picture is friggin' awesome in the context of an ABS discussion!

2.  If by point of lock you mean just before the wheel locks, then isn't that basically what ABS does?  Holding the brakes to this point is perfect braking and is beyond my skill level in the real world, at least consistently.  I bought my Beemer in '94 specifically because it had ABS and I've had many instances to appreciate it in the years since.  The ABS (and TCS) on the Cali 1400 are even better.

yeah maybe.
The more I think about it, the more questions it raises for me.
I KNOW !!!
I'll just stop thinking about it...

[oldbike54]

 Peter , notice that slight stinging sensation in your hamstring ? That is where I hit you with a tranquilizer dart , the calming effect will begin in a minute or so 

 Dusty

[Idontwantapickle]

Although the relative wheel speed front to rear is a factor for the ABS, it is also programmed to recognize a rotational change that would defy the ability of the equipment. In other words it can see change over time that is outside the norm and react. It knows how fast the bike can stop.

Hunter

[Huzo]

Peter , notice that slight stinging sensation in your hamstring ? That is where I hit you with a tranquilizer dart , the calming effect will begin in a minute or so 

 Dusty

Thanks Dusty, your calming tone will suffice

[Huzo]

Although the relative wheel speed front to rear is a factor for the ABS, it is also programmed to recognize a rotational change that would defy the ability of the equipment. In other words it can see change over time that is outside the norm and react. It knows how fast the bike can stop.

Hunter

Jeepers ! I don't get how it does it but that sounds plausible.
Okay.

[Sheepdog]

I’m no automotive engineer, but I’m pretty sure that differential wheel rotation is only one parameter that the ABS evaluates. There are probably some accelerometers and/or inclinometers in there, too. Some of the newer bikes even consider lean angles and throttle modes in the ABS/TC protocols. ABS and traction control have come a long way...

[Huzo]

I�m no automotive engineer, but I�m pretty sure that differential wheel rotation is only one parameter that the ABS evaluates. There are probably some accelerometers and/or inclinometers in there, too. Some of the newer bikes even consider lean angles and throttle modes in the ABS/TC protocols. ABS and traction control have come a long way...

Inclinometers would require gyro's, so I'd be dubious on that one when it comes to our Guzzies, although I'm aware more sophisticated units are fitted to later BMW's and such.
However, I've learned not to be surprised at being surprised.

[Tom]

You can't do a sliding stop on gravel with an ABS bike.   

[Noguzznoglory]

while the system may consider difference in rotation speed between front and rear it will still modulate the braking to each wheel independently.  i have never felt the abs function on the front wheel on my F800GT but in loose sand or gravel i have felt the rear wheel modulating.

[Huzo]

while the system may consider difference in rotation speed between front and rear it will still modulate the braking to each wheel independently.  i have never felt the abs function on the front wheel on my F800GT but in loose sand or gravel i have felt the rear wheel modulating.

Me either.
Of course the weight transfer under braking will load the front wheel and reduce the tendency to "lock", so delay the onset of ABS intervention.