BRIDGESTONE S21
TIRE TEST
P92
The new
tread pattern
is claimed to
increase high-
speed stability.
The front S21 has
a much larger
hard center
compound than
the rear.
The real acid test
for the tire will be
if Bridgestone's
claim of 36
percent longer
mileage can be
backed up in the
real world.
FRONT AND REAR CONSTRUCTION
Bridgestone has used their standard three-layer compound
(3LC) with high stiffness bead fillers in the front S21, with a
harder center construction to aid that massive claim of an
extra 36 percent gain in mileage.
The front tire's crown is slightly smaller compared to the
S20EVO with the shoulders also a touch lower. This is aimed
at increased turn rate and side-to-side agility, while still
remaining stable when cranked over. Again, more tire on the
ground equals more traction.
As for the rear tire, it's the opposite of the front in that it
now features a larger crown for increased stability under
acceleration. Bridgestone is claiming the rear S21 tire
has 30 percent less slip in the contact area than the old
S20EVO, enabling the tire to lap two seconds faster than the
S20EVO at the Sugo test facility in Japan (the same venue
that hosted WorldSBK during the late 90s and early 2000s).
The rear tire is made up of five separate compounds with
the stiffer construction again in the center, but the softer
compounds in the shoulders of both the front and rear tires
are all-new, proving a larger micro contact patch that aids
turn-in speed and greater mid-corner stability.
