VOLUME ISSUE AUGUST , P103
Development and Cyber, Pierangelo Mis-
ani. "The speed was starting to be more
important. The world of motorcycling in
terms of tires had always been based
in the past on cross-ply construction.
However, the automotive segment had
already switched to steel radials some
20 years prior, but the motorcycle world
had not yet adapted."
This was an optimistic time at Pirelli,
which had earlier in 1979 completed the
purchase of Metzeler and bought every
-
thing in house. The first innovation came
in the form of the Metzeler Belted System
(MBS), developed for the diagonal Kevlar
belt on cross-ply tires of the 1980s, but
it was only the beginning.
A tire is nothing but a spring, or, rather,
a spring and a damper.
"The spring is made by the construc-
tion, by the carcass. The damper is all
the rubber that is inside," says Misani.
"Bikes are inherently unstable. The only
way to make them stable is the tire, but
the tire also creates a character to the
bike. As a tire wears down, many as-
sume it just loses grip. That is true to
some extent, but what really happens is
the wearing down of rubber means you
lose the damping effect the tire was
designed to give. Less rubber, less
damping of the forces."
Where steel showed its real benefit
was in compression resistance—again,
learned from the automotive side that
required high sidewall strength to avoid
deformation. For a bike, it allowed the
tread to stay uniformly connected to the
road while the motorcycle was leaned
over without caving in on itself and you
crashing to the ground.
Over time, Kevlar tire belts had
moved from 90° to the direction of trav
-
el, to alternating 35-40° patterns with
the MBS. Now, the option of a 0° belt
became a possibility, but using steel.
Legendary
German rider
Helmut Dähne on
his way to breaking
the Nürburgring
Nordschleife lap
record in 1991 on
pre-production
0° belt Metzeler
radials.
