Re: ABS

["Steve Makohin" <wateredg@xxxxxxxxxxxx>]

Hello Dan,

Thanks for your reply. I have snipped material with which I have no 
contention.

(original dialog}

Dan:
>> I also disclaim the notion that one stops sooner than the other. I just
>> don't know that from my experiences.

Steve:
> Could you please clarify the meaning of your closing sentence above?...




From: "Seattle Dan" <danweb@xxxxxxxxxxxx>

> No problem. What I actually meant by that disclaimer is not covered by 
> your
> multiple choice. Here's clarification on both though:
>
> 1) I'm a big believer that ABS is great for 'non pro' riders...
[...]

I agree with your statement above providing that it is qualified by the 
additional proviso of "under racing conditions". Tests have concluded that 
even the best motorcyclists, those being world-class professional racers, 
are better off with motorcycle ABS than without under the majority of 
scenarios when riding on the street. Let me know if you would like me to 
itemize a number of those scenarios.



[...]
> 2) Yesterday's comment was about the difference between Honda VFR
> ABS vs BMW ABS. For this I didn't want to say which would stop me
> faster in absolute terms.

>From the material I have read, various reviewers have commented extremely 
positively about the VFR's ABS (I don't know if these comments pertained to 
a specific year's model). The context of those very positive comments was 
not the stopping distance (i.e., they did not devise a test to determine 
which *brand* of ABS, such as BMW vs Honda, delivers the shortest stopping 
distances, presumably because so many other factors play a part such as the 
design of the bike being used), but rather, the "feel" when ABS kicked in.

According to many motorcycle magazine reviewers, including Cycle Canada 
(renown for their non-biased, stick-to-the-facts writing style), Honda's ABS 
shines because it is "uneventful" when ABS kicks in. The transition from 
normal braking to an ABS-engaged state is smooth, whereas other systems are 
abrupt and may alarm the rider. Additionally, while ABS is engaged and doing 
its work cycling the brakes, reviewers alleged that Honda's ABS feels much 
smoother than other systems. BMW's comes to mind, where I can actually feel 
the ABS pulses, which translate into vibration in the handle bars. This too 
may be unsettling to some riders.

The conclusions I drew from this information, is that Honda's ABS 
implementation on the tested VFR *feels* considerably better than others. I 
take my hat off to Honda for creating ABS that feels so good as to receive 
widespread critical acclaim.




[...]
>  A true pucker moment -- Toss up / not sure
> Because I'm beginning to feel that after every day riding of
> the GS that I'd NOT give it a fist full but rather gradually apply
>  the brakes. It has trained me to be more cautious. This would
> cost me precious stopping distance. Another side of me says
> that in a true pucker moment, I would grab a fist full
> without any hesitation.
[...]

Your comment above touches upon a topic that is somewhat related to ABS: 
Linked brakes, and servo-controlled brakes. I'd like to relate them to your 
comments above.

I spent 4 seasons and 20,000 km on an R1100S (2000 model year) with ABS, 
non-linked, non-servo brakes. I have also ridden an R1100S (2001 model year) 
for 1 season and 7,000 km with ABS, semi-linked, servo-controlled brakes. As 
a result of a fairly long trial with both systems, combined with my research 
on the subject, I feel safe in asserting the following:

 o My personal preference for brake feel is non-servo controlled
   brakes. The servo brakes seem to "come on" too suddenly for
   by taste when I first apply them. This applies only to the hand
   lever which is linked to the front and rear brakes, and not to
   the foot pedal which actuates the rear brake only. Comments
   apply to my semi-linked brakes.

 o I felt I could modulate the non-servo brakes better, so I could
   get closer to the locking threshold without actually activating the
   ABS than with the servo brakes. This is useful for planned, quick
   deceleration from high speeds. This statement is "perception
   only", as I have no facts to disclose as to whether either system
   is "better" in some way in this regard.

 o I have learned to adapt to the servo brakes by "choking up" on
   the hand brake lever. That is, I use only two fingers to apply the
   brake lever, and I position them as closely to the lever's "hinge"
   as possible. This reduced the amount of leverage I can use, and
   therefore, applies less brake force per finger force applied. This
   technique has allowed me to brake pretty smoothly.

 o Extensive studies with cars and motorcycles show that in an
   emergency, the operator often does not apply brakes early
   enough, or hard enough, to maximize brake effectiveness, and
   thereby unnecessarily lengthens stopping distance. BMW's
   servo brakes (and Mercedes as well) try to compensate for
   this reality by (a) detecting what they *believe* is an emergency
   application of brakes (rapid application), and then (b) rapidly
   increasing brake pressure (e.g., that sudden "grabby" feel), and
   (c) under certain conditions, raising brake pressure to the
   maximum level automatically.
      In extensive test in which vehicle operators were "surprised"
   by an emergency situation, servo brakes were effective in
   shortening stopping distances when combined with ABS as
   compared to non-servo ABS brakes.

Even though I know the facts, those being that BMW's servo brakes may save 
my butt one day by stopping me a few feet short of a collision, emotionally 
speaking, I still prefer the feel of BMW's non-servo brakes.

- -Steve Makohin
 '01 R1100S/ABS
 Oakville, Ontario, Canada 

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