TECH / ISSUE 3 2019 / 77“For typical motorcycle tire R&D, there are four main
technical phases,” he says. “The first is the central
research and development. It’s our engineer in the head-
quarters. He is sort of the orchestra director.
“The second important figure is the blend,” Frare adds.
“It’s just like making a sandwich. You decide what process
you will use in making the cheese, for example. And you
can decide which process you will use to bake the bread.
Once you put it together, you make the sandwich.”
This “sandwich-making” process is perhaps the most
complex and for precise control the once-manual opera-
tion has become automated.
“Once for example, you were manually laminating the
textile fibers and the rubber of the textile fiber,” Frare
says. “This process went progressively more automated.
This is one of the first things we started to do back in
the 1980s. Now we put the raw ingredients on a table
and you will receive the ‘baked’ tire. Of course, you need
someone who controls these processes and checks that
the parameters are correct.”
He goes on to explain that advances in and control of
the process allows more finely dispersed ingredients in
tire compounds.
“Imagine a sponge made up of large stones,” Frare
says. “If you scrub it on a surface, you will progressively
lose these large stones. So the risk is that you wear it out
quite quickly.”
He says that by essentially making the elements of
the tire smaller and thinner, the amount of material you
lose when you scrub it against the ground is reduced
and therefore lasts longer and wears more uniformly.
This also facilitates a stronger structure, because more
individual particles can form more chemical bonds when
measured pound for pound against older processes.
The method used to “cook” the compounds is yet
another critical factor, as is the variation of temperature
applied during final curing.
“We are not simply scrubbing and mixing thinner
and thinner particles,” Frare adds. “The key is to ensure
slow, controllable parametric mixing where the right
ingredients can enter the mixing process at the right
point, without risk of overheating. This is one of the best
processes developed by Pirelli in recent years.“
Following these first two steps, prototype tires are
then thoroughly tested in a lab setting at Pirelli’s Milan
headquarters to ensure the tire meets homologation and
legislative requirements, as well as demonstrating the
hoped for performance characteristics.
The fun part comes fourth, at least for us rider types:
outdoor testing, which is basically what we got to do on
our rapid-fire, 17-bike, two-day rip all over Sicily. This is
where Pirelli’s real-world testing is conducted, thanks to
the island’s ideal mix of terrain, weather, and often slick,
soot-covered asphalt. There is a large dedicated off-road
test facility, as well as the Pergusa racetrack, which Pirelli
leases for exclusive use from the city.
You can thank the active volcano that is Mount Etna
for making Pirelli’s outdoor testing “lab” so interesting,
challenging, and beautiful. Our trip to sample essential-
ly the whole tire lineup from dirt to asphalt racetrack
demonstrates how far tires have come, and how quietly
integral to overall performance they are. Black rubber
“sandwich making” is sure to evolve even more. nTOP LEFT: A zero-degree steel-belted carcass waits for application
of tread rubber. TOP RIGHT: Pirelli operates motorcycle-tire factories
in Brazil, China, Germany, and Indonesia and manufactures nearly
2 million tires annually.