Singletrack

STEP INSIDE MY LAB
Tyred and Tested!
Even to a self-confessed tyre geek, the array of acronyms,
abbreviations and hieroglyphics on tyre sidewalls can be
downright baffling: TR, TCS, TRSR, Addix, 60 vs 120TPI,
40a, 42a or 60a, Dual compound, 3C and so on.
Fortunately, it’s all pretty straightforward when
broken down and there are three main factors to take into
consideration when looking for a tyre – the casing, the
compound, and the tread pattern.
Casing
The casing is ultimately what holds the tyre together. A tightly
woven fabric wraps around the bead and overlaps under the
tread. A higher thread count (TPI) makes for more densely
woven casing that makes the tyre more supple, but ultimately
how thick the casing is will determine how durable the tyre is
overall. Most trail tyres use a single or 1.5 ply casing, downhill
tyres are dual ply, and in some extreme cases (pun only mildly
intended), manufacturers spec triple ply tyres for maximum
protection against rock strikes. Most manufacturers also offer
additional layers of sidewall protection on some models, to
prevent both pinch punctures and slashes to the sidewalls
from passing rocks, and these are usually strategically placed to
provide maximum protection for minimal weight gain. As for
tubeless compatibility, all the tyres on test claim to be tubeless
ready (meaning they’re designed to work with the addition of
sealant), but they went up with various degrees of difficulty.
Some popped up onto the rim with ease, while others refused
to play ball even after resorting to putting a tube in.
The Compound
Typically measured in Shore A (a), from 0a to 90a, with 0
being the softest and 90 the hardest, most mountain bike tyres
fall in the range of 40a (super-soft downhill and mud tyres) to
60a (more all-round use). A softer compound will give more
grip, but will wear faster and be draggier on the climbs and
tarmac, while harder compounds last longer and roll faster,
but are less grippy, especially in the wet. Manufacturers are
constantly striving for the holy grail of a tyre that has loads
of grip, but doesn’t drag or wear too quickly. They look to
achieve this by fine-tuning the balance of ingredients in the
compound, or by using different compounds in different
places of the tyre – you’ll commonly find a harder compound
on high wear areas (the centre of the tyre) paired with a softer
compound on areas where maximum grip is needed (the
edges), and some manufacturers go as far as to use a triple
compound construction. By using a super-firm compound at
the base, and softer rubber elsewhere in the tread, they’re able
to make the tyre less prone to squirming about under load,
than with a softer dual compound tyre.
The Tread Pattern
Bigger, chunkier knobs are a good thing right? Wrong! Well,
not always… Bigger knobs do a great job of digging down
into mud and loose dirt but they can be skittish on harder
surfaces as the rubber folds under itself and gives way, leading
to a loss of grip just when you need it most. Likewise, smaller
knobs are great on harder surfaces and roll faster on tarmac
and fire roads, but clog up quicker and lose traction when
things get loose. You also need to strike a balance between
traction for pedalling, braking traction, and directional
grip for cornering, and that’s without taking into account
personal preference and riding style. Rounder tread profiles
can build confidence in some riders as there is a less noticeable
transition from the centre blocks to the cornering edges, while
others prefer having a squarer profile with a definite transition
onto the cornering edges of the tyre and really love the feeling
of those edges hooking up into the ground.
So which tyres should you buy? Well, it’s really a matter of
how and where you ride. All the tyres on test shone in some
areas and less so in others, so it’s a question of deciding which
factors are most important to you and striking that balance.
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