page 4 summery of abs test
With that information in hand, we ran a second non-ABS test but found that
without the ABS safety, net, stopping distances were, on average, only 11
feet shorter than the first set of non-ABS tests. Every tester agreed that
with knowing the ABS was there to catch them, pushing the braking envelope
to the outer edge was not a problem for them.
In A Turn
Unfortunately, anti-lock brakes are not very effective while cornering. Ask
an engineer and he'll get this far-away, glassy look and start talking
about tire slip ratios, lean angles and traction coefficients. Roughly
translated, it means this: The farther you lean over, the less traction is
available for braking (or acceleration). Get on the brakes hard in a
corner and long before either wheel lock, you'll find yourself sliding.
When a tire loses its grip, the slide is toward the outside of the turn.
Getting off the brakes (or the throttle) may not be enough to regain
directional control (the motorcycle is trying to go sideways, not forward,
you'll need to help the process along by steering with the bars. It's a
pretty intense maneuver.
So, if ABS can prevent wheel lock-ups, what's the problem in turns?
Unfortunately, today's generation of ABS, though quite complex, does not
account for lean angles. The same computer logic for straight-line braking
(i.e., calibrated to allow near tire-smoking stops) does not apply when
tilted over. Someday faster computers with more capacity to handle
increasingly complex ABS programs, combined with faster hydraulics with
the ability to regulate (not just modulate) brake line pressures, may be
able to solve the problem.
Still, the ultimate answer, as one source hinted, may be the addition of
lean-angle sensors and computers that completely take over the full-tilt
braking chores. A solution that will take years of R & D to sort through,
and even then will only happen if riders are willing to accept an
increasing level of automation.
ABS Operation Over Other Hazards
Although we tested ABS on a variety of surfaces, braking problems could be
broken down into two basic groups: Limited distance hazards (such as metal
gratings, tar strips, a patch of sand, gravel, or dirt), and long-distance
hazards (wet pavement and dirt roads).
Oil and grease created a unique problem. During one of our tests (run at
30 mph due to the location), while crossing a 13-inch patch of oil mixed
with some grease and dirt, the tires picked up enough gunk to be a problem
as the same spot came around on the next rotation, six feet down the road.
After our Racer nearly lost it on a non-ABS Yamaha, we limited the test to
ABS only. ABS didn't bat an eye at this challenge. It simply went through
the gunk and cycled two to five times until the garbage scrubbed off the
tires.
We also incorporated another test not on our original list. One of our BMW
riders reported missing a stop sign on a rainy night. Not entirely
unusual, except that the road ended (Illinois farm roads tend to end in
T's quite often-a real problem if you're not alert) and he found himself
on a farmer's lawn going 40 to 50 mph. To verify his claim of a "a very
long, but controlled stop," we ran the ABS Yamaha and ABS BMW over a newly
sodded, water-soaked lawn. While a series of passes would have been nice,
no one was willing to let us destroy their lawn. We were limited to three
test passes.
Next to ice, wet grass is about as slippery as it gets. Our reader was
correct. Both the BMW and Yamaha models with ABS came to a nice, controlled
stop in a reasonable distance. And yes, ABS does work on ice, too. Given
that we didn't get our hands on the Yamaha until the end of March and the
Honda until June, a comparison was not possible (besides, no one was
really anxious to try it anyway). However, we did book some winter miles
on a BMW K100LT-ABS. Winter riding also brought out another problem. In
temperatures lower than -5 degrees F, the drag from the wheel bearing
grease and the brake pads rubbing against the discs keeps the wheels from
turning after ABS releases the brakes (on ice). That's not an engineering
problem related to ABS, but rather a cold weather problem you should be
aware of.
On dirt roads, ABS wasn't even flexing its muscles. Like the wet pavement
tests, riders were amazed at how much traction was actually available.
Gravel was the same story. Without the fear of a slide-out, you can
actually feel the tires gripping against the tiny, loose rocks as they
move around under the wheels. Now that is impressive!
In Conclusion
If we are to try to pick a winner of this "contest," based on both the
stopping data and the testers' comments, it would have to be the Yamaha
FJ1200 ABS. Though all the ABS systems worked extremely well, it was
unanimously felt that the Yamaha system worked the smoothest and was the
easiest to handle. The lever and pedal "feedback" were the least harsh and
obtrusive on the FJ, and therefore probably less likely to disturb or
frighten the rider into over-reacting during a high-stress, panic stop
situation.
In the end, everyone could hardly believe just how good ABS really is.
It's certainly not a sales gimmick. This is clearly the biggest advance in
braking safety since the advent of the disc brake. Our group of testers
had just one complaint: Why is ABS not available on more motorcycles?
At least part of the answer to that question lies in our own resistance to
change and, in particular, to bikers' reluctance to abdicate any amount of
control of their mounts to "technology." We're a fairly independent lot,
and take a certain amount of pride in the fact that we regularly rely on
our own abilities and talents to get ourselves out of trouble.
Still another part of the answer comes with the rather large cost of ABS.
High-tech braking has a price, and it's one that is high enough to make
most of us stop and think twice about purchasing it. BMW's system adds
$1000 and 20 pounds to the equivalent non-ABS models. Honda's system
weighs 11 pounds and raises the ST's price tag by $1900 (though to be
fair, that also includes the Traction Control System, which we will test
in a future issue). The Yamaha is the light-weight king at 9 pounds,
adding $1200 to the FJ's retail price.
I guess in the end the only real question is not whether or not you can
afford ABS, but can you afford to ride without it?
If you would like to see the entire test, let me know.
