 |
Why do fleets need a
better steer tire? For the past 8 years, fleet managers have been pressured
to find as many productive ways as possible to lower the overall cost-per-mile. Many have
asked tire manufacturers- including Bridgestone-to create a steer tire that combines great
wet traction, long even wear and a fuel-efficient, highly retreadable casing. Features
that can currently be found individually on a tire, but not all available in a single
tire. A request that suggested a total revolution in steer tire technology, since existing
technologies couldn't be revised to accommodate all the features needed. Bridgestone
engineers listened and responded to the challenge. After 5 years of intensive testing, the
revolutionary R227 steer tire is now a reality. |
What's
So Revolutionary About the R227?
The R227 has features unlike any tire you've seen
or used in the past.
True, it has some similarities to previous Bridgestone tires,
such as a unidirectional design.(After all, it makes sense to retain all the things that
work well, fit the design objectives and don't need to change.) But it also has some
revolutionary differences -like a new Side Groove feature, an Equalizer Rib, new
high-performance compounding and an all-steel casing.
Unidirectional Tread Patterns
Aren't New, Are They?
Not on performance tires-for passenger cars. But
on steer radials for heavy duty trucks, they're quite an innovation. In fact, Bridgestone
pioneered the idea of a unidirectional steer tire pattern with the highly successful R226.
When you design a tread to roll only one way, you can really fine
tune it for optimum traction and wear characteristics. With the Bridgestone R226 fleets
saw whopping increases in tread life, resistance to irregular wear, as well as traction.
It just made sense to keep these characteristics in the design of the R227.
Why the Side Grooves?
Traditionally, steer tires use what are called "decoupling" ribs to fight
irregular shoulder wear. These actually do a pretty good job. But they have some built-in
drawbacks: For one, they do nothing to combat irregular wear resulting from side forces
during turns, maneuvering or even cross winds on long combination vehicles.
And, because they are directly in contact with the road, they
tend to get damaged-or even torn away-if you do a lot of turning and maneuvering. Or, they
pick up and trap small stones. These stones then become the seeds of irregular wear, which
can continue even after the stones are removed.
Bridgestone engineers created side grooves that maintain more
uniform tread contact pressure to fight shoulder edge wear-especially from turning side
forces.
The R227 puts that extra rubber on the road, where it will work for you. And because the
side grooves are positioned away from the road surface, the R227 won't tear or collect
stones.
|
 |
|
What's the Equalizer Rib All About?
It's another revolutionary idea Bridgestone
engineers developed. Basically, the design helps absorb river or wavy wear forces so that
the pressure is more uniformly distributed across the main ribs. And, the angled shape
helps prevent stone retention that could result in casing-damaging stone drilling or even
provide a starting point from which more serious irregular wear can spread.
Which means that the R227 wears evenly for a longer time.
The fact is, this feature is one of the more critical features of
the R227. After all, irregular wear has been
a major concern in the past. Because the longer a tire lasts, the worse the problem can
be. And this tire can last a very long time. But with the combination of Side Grooves,
Equalizer Ribs, and the unidirectional pattern design, irregular wear isn't such a big
concern anymore. |
How Do You Stop Irregular Wear?
You don't. You try to reduce it or delay it through a strategy of continuous improvement
in tread compounding, tread and shoulder design and in casing contour.
For more than two decades, that has been a primary mission for
Bridgestone designers and engineers-with some exceptionally rewarding results. That might
explain why many Bridgestone innovations are gradually being incorporated into today's
truck tire technologies.
The R227 represents a significant advance in wear reduction
technology, as you can see below. But more work still needs to be done so that irregular
wear will become even less of a problem in the future. You can be assured that Bridgestone
engineers and designers will soon discover even more answers.
Why Did You Use
a Different Tread Compound?
Not only is the compound "different," it's new
and created for high performance applications (which also means it is suitable for most
conditions). It's formulated to run cooler, wear slowly, resist tearing and reduce rolling
resistance. That results in superb, dependable performance and exceptional wet traction.
How does it do that? Well, let's just say that this new tread
compound marries the best characteristics of natural rubber with those of some rather
precisely engineered synthetic rubber. So precisely engineered, in fact, that like the
Side GroovesTM and Equalizer RibsTM, it's protected by a patent.
(But, honestly, we're not
going to divulge all the details of this formula. We don't want to make life that easy for
our competitors.)
What Makes the Casing Design So Different?
When we set out to revolutionize steer tire
design, we realized the casing technology would be critical. That's why we created an
all-steel casing that maintains its original new shape, still another technique of
resisting irregular wear. The new casing fights heat build-up by balancing stresses in the
tread, sidewall and bead areas. This technology increases fuel efficiency-not only during
original steer applications, but also for drive and trailer applications once it has been
retreaded.
And remember, casing retreadability has always been a distinguishing advantage of
Bridgestone tires.
How Well Does the R227 Perform?
The R227 is truly a revolutionary steer tire. But
Bridgestone engineers didn't just design this tire and turn it loose in the market. In
fact, this tire has been
put through some of the most rigorous tests-and survived them-that we have ever put a tire
through.
(That says a lot, since you're
probably already aware of Bridgestone's obsession with testing tires.)
The R227 performs incredibly well. |
|
|
|
|
How's the Traction in Wet Conditions?
More reliable than you can imagine.
The R227's unidirectional tread pattern has hundreds of
precisely-angled sipes that slice through water and then pump it out of the footprint to
ensure exceptional wet traction and stopping power, as well as precise, easy steering.
In fact, test after test, the R227 beat leading competitive
tires.
By driving the R227 over a thick glass plate and photographing it
from underneath with a high speed camera, Bridgestone engineers were able to see that what
they designed the tire to do was actually happening.
As you can see in this photo, the R227 pushes water in front of
it out of the way. And pumps the rest out behind it. Notice also that there's almost no
spray out the sides of the tire.
That means virtually most of the water underfoot has been driven
into the grooves and out of the footprint. The result is a huge footprint-making solid
contact with the road surface-for confident handling and pinpoint control. 
In wet stopping power tests at Bridgestone's Ft. Stockton Test
Center, tractors equipped with R227 radials demonstrated better wet stopping over
competitors.
This "road's-eye" view of the R227, as it drives across
a water-covered sheet of glass at 30 mph, shows a nearly ideal footprint shape and
excellent water evacuation. |
 How Does the R227
Improve Fuel Economy?
In a number of ways.
To begin with, the R227's tread pattern and compound are
inherently fuel efficient. They were designed to conserve fuel-but not at the expense of
tread life or traction. Because you made it clear that you wouldn't trade long tread
life-or traction-for fuel economy.
But with most fuel-efficient tires, the benefits completely go
away when the tread does and they don't return when the tire is retreaded.
Bridgestone engineers also built fuel efficiency into the casing
so the R227 will help save fuel-even when it is retreaded. The casing technology is
revolutionary in its ability to fight stress, generate less heat and use less fuel.
That means the R227 not only saves fuel when it's new, but
throughout its life. At the same time, because this new casing generates less heat-and
because heat
is the number one killer of casings-the R227 casing is "as retreadable as a
Bridgestone."
That means that you'll get to enjoy fuel efficiency benefits over
and over again. |
|
|
|
|
How Long Will the Tread Last?
Much longer than you expect.
Bridgestone engineers know that tread life is critical for steer
tire performance. That's why they tested it exhaustively in a variety of conditions in
both long and regional haul applications-against other Bridgestones as well as competitive
tires.
The R227 won the battle- almost embarrassingly.
What's the Real Value of the R227?
The real value of the R227 lies in the questions
fleet managers asked (and complained about) a while back.
In answering those questions, Bridgestone engineers discovered
that for a steer tire to be able to help significantly lower the cost per mile, it must be
built to wear evenly, last a long time, offer superb wet traction and have fuel efficiency
built into the casing so it will remain after retreading. (Like every Bridgestone tire,
the R227 is unusually retreadable. Tire Retreading/ Repair Journal named Bridgestone #1 in
retreadability in 1995-the 10th year in a row. In the history of the survey, no tire has
ever outranked Bridgestone.)
We invite you to examine and test the revolutionary new R227
steer tire.
When you do, you'll discover how it will save money for you.
Simply, it's worth it.
What's Next?
Bridgestone engineers are working on it right now.
|
 |
 |
This is what a brand new
Bridgestone R227 looks like. |
TThis is what a Bridgestone R227
looked like after running 217,810 miles. 9.5/32nds of tread remains.* |
|
* This tire was used in a long haul
operation with an excellent maintenance program. Your tread life and irregular wear
experience may vary, depending on equipment, equipment maintenance and conditions of use. |
|
|
| << close >> |
| |
© 2006-2010 Bridgestone Americas Tire Operations, LLC l legal notice |
|
|
