makes short-haul tires wear out so fast?
Mostly, it’s scrub. When you turn, they scrub against
the pavement. That’s like dragging an eraser across
The more turning and maneuvering you do, the more you grind
away that tread.
||At 22/32" the
new Bridgestone R260F
is more than 20 percent deeper than conventional steer
So what’s the answer?
One solution is a deeper tread. Most steer radials are about
18/32" deep. Generally, adding tread lengthens wear.
Why don’t steer tires have
The problem that can accompany deeper treads is irregular
wear. For years, 18/32" has seemed to balance long tread
life and low irregular wear.
What kinds of irregular wear?
Generally, it starts along rib edges and then spreads.
Because steer tires have to be removed, by law, when any
part of the tread is at 4/32" or less, irregular wear
can be a major cause of premature tire removal.
Is there a solution?
Make a steer tire with a deeper tread, and figure out a way
to reduce or prevent irregular wear.
Like the new Bridgestone R260F. It combines a 22/32" tread,
more than 20 percent deeper than conventional steer radials,
with irregular wear-fighting features to help you get even wear.
Equalizer Rib design
fights irregular wear using tiny ribs that sacrifice
themselves by wearing much more quickly than
the main ribs beside them.
How does the R260F fight irregular wear?
Notice the narrow ribs alongside the two main ribs. These are
called Equalizer Rib™ structures – a patented, Bridgestone-exclusive
innovation to fight irregular wear.
How do they work?
These tiny ribs are just a bit shorter than the others, so
they are like the smaller tire in a mismatched dual pair.
They wear faster than the main ribs beside them, just as the
smaller tire in a mismatched dual pair does.
In doing so, they attract irregular wear forces that otherwise
would attack the main ribs. In a sense, they sacrifice themselves
to protect the main ribs.
The R260F’s Equalizer Rib design effectively channels
irregular wear-producing forces away from the main ribs and
into these small ribs, combating irregular wear.
Isn’t this what happens
with your Defense Groove™ design?
Similar, but unlike Defense Groove tires, these ribs are
located away from the shoulders. Still, what works for shoulders
seems to work on inner ribs too.
Does the R260F also use the Defense
In short hauls or P&D service, that structure usually
isn’t necessary. High scrub seems to “rub out”
shoulder wear before it can become a problem. And, when tires
are constantly turning and maneuvering, there’s a tendency
for that outer rib to be damaged or torn, causing more severe
Does the R260F have other
features to combat irregular wear?
In addition to
the Equalizer Rib structures, notice the tiny notches along
the rib edges.
|Tiny notches, called “stress
reduce squirm and scrub that can initiate rib edge
What do they do?
A tire is round, except in its footprint. There, the round shape
That causes stress and scrubbing along rib edges. This almost
microscopic scrub can be a seed of irregular wear.
in the rib edge allow it to be flattened with reduced edge
stress. Called “stress relief siping,” these notches
are very effective against irregular wear.
How is the R260F’s retreadability?
Like all Bridgestone radials, the R260F is designed to be
retreaded. And a few special features make it a good retreading
Notice the shape of the Equalizer Rib structures and those
little “buttons” at the bottom of the inside grooves?
Both are designed to prevent stones from being captured.
|The sloped shape of the
structures in the R260F help prevent damaging
stones from being captured and retained.
Why is that?
As a tire wears, retained stones are pushed into the tread.
Eventually, they can drill into the belts, damaging them and
allowing water and air to get in and cause rust.
Both belt damage and rust reduce retreadability.
platforms at the bottom of the R260F’s inner
grooveshelp prevent stone drilling that can damage
and cause them to rust, reducing retreadability.
The R260F, like any Bridgestone with
the letter “F” in its model name, has thick sidewall
These ribs shield sidewalls from cuts and abrasion, prolonging
useful life. And, because both sidewalls are ribbed, if one
set gets worn away, you can flip the tire over for continued
ribs on both
sidewalls help protect R260F
casings from curbing damage.
When will the R260F be available?
It’s available in 22.5 and 24.5 standard and low profile
sizes. Ask your dealer for more information, or check the
box on the business reply card in this issue of Real Answers
for a brochure on the R260F. It’s just the thing for
stretching tire life in high scrub applications.
free brochure on the R260 is available
from dealers, Bridgestone Representatives
or by requestingone from the Tire