DT May 2018

The Karoo 3: Dedicated to off-road trail
riding and adventure journeys, aggressively
offroady, works OK on tar albeit a bit on the
noisy side. The noise does distract and it
does not last too long…
The new Karoo Street: Is a unique
combination of off-road looks and traction
with on-road agility. A true 50/50 tyre. That’s
what we were there to sus out…
Techy stuff:
Tyre Compound:
Stiffness is needed to:
Support the profile (that characterizes the
handling), define the footprint area (which
engages the compound and generates grip),
wear resistance, thrust and load derived
from rolling tyre dynamics.
Softness is needed to:
Absorb shocks and hits, Copy terrain
asperities.
The Karoo Street has a high Silica (that’s
the sticky stuff) compound with a balanced
proportion of carbon-black (that’s the stiff
stuff under the sticky stuff) and resins to
achieve a high level of grip on road, in
both dry and wet conditions. A relevant
percentage of Carbon Black filler still is
needed to increase knobs resistance to
‘tearing’ and premature wear when used
on-road.
Tread pattern design:
Much of Karoo Street’s performance is
delivered by a tread pattern evolved from the
layout of Karoo 3 and its uniquely shaped
knobs. The main focus of its development
was to provide great on-road performance
with consistent wear, greater mileage, and
a high level of stability combined with the
ability to hit the dirt tracks.
Extra-large central blocks create a wide
and solid contact patch to ensure both
low and high speed stability on-road. The
footprint characteristics are balanced to
promote uniform wear, thus providing
valuable mileage for this class of tyre.
We asked what mileage to expect. The
answer was around 10000 kilometres on the
rear assuming that the rider does 80 percent
tar, twenty on dirt.
When riding off-road, the V-shaped knob
layout causes multiple operating edges of
blocks to ensure acceleration, traction and
braking grip.
The combination of these characteristics
(extra-large blocks and V shaped layout)
and their effect (stability, traction, wide
contact patch, smooth rolling) helps the
tyres to integrate with electronic rider aids
such as ABS and Traction Control. (See,
we told you.)
Longitudinal grooves in the middle of the
central blocks provide water evacuation
and self cleaning ability for dirt. Wide
transversal grooves contribute to make
central blocks to dig the soil, providing
offroad traction especially on dirt and hardpacked
clay soils.
The variable block shape (together with
the V-shaped knob layout) ensures several
contemporarily operating edges with mixed
orientation, capable to enhance off-road
traction in several conditions.
Big lateral blocks with narrow grooves
ensure a large contact patch, giving proper
cornering grip and stability when leaning
on-road.
It all sounds like a lot – but there you go.
And we bet that you learned a bit.
The ride:
The boys and girls from Metzeler instructed
us all to ride as hard as we liked. No sissy
stuff. “Try and slide, brake hard, enjoy
yourselves, we want to test the tyres to the
maximum.”
What a cool ride we had – everyone raves
about riding in SA – and we could not agree
more, we are truly blessed, but riding in
16 DIRT & TRAIL MAGAZINE MAY 2018