Tyre
Tip 3 - Maintaining Your Tyres

We are all aware of the necessity to operate truck tyres within the
recommended parameters of correct inflation pressures, alignment
settings, loading, speed, and eventually remove the tyres when the
treadwear indicators tell us it's time. But what is the bottom line
when these factors are not quite optimum, what does it cost us
through not maintaining our tyres?
The short answer
is, quite a lot.
While the tyre
manufacturer can extol the virtues of new constructions or
innovative compounds to give benefits in treadlife, stability, fuel
economy, safety, etc.; you, the truck operator can cause all these
attributes to be nullified by simple maintenance negligence.
For a start,
lets look at tyre inflation pressures. We know that tyres are
designed to operate at specific deflections and optimum footprint
configurations, with inflation pressures adjusted to achieve this at
the various loads.
Generally we
find that if a tyre is under inflated, this leads to:
• Increased
flexing, which causes the tyre to overheat and may cause tyre
failure.
• Increased wear, which in turn equals shorter service life. As a
general rule if a tyre is run, say, twenty percent under inflated
then expect its service life to be shortened by a similar twenty
percent.
• Higher rolling resistance and subsequent increased fuel
consumption. This twenty percent rule of thumb continues to apply in
this aspect as well, so twenty percent under inflation roughly
equates to twenty percent increased tyre rolling resistance, which
in turn converts to three or four percent decrease in vehicle fuel
economy. How much was your annual fuel bill?
• Irregular wear.
While over
inflating tyres doesn't have the same deleterious effect as under
inflating, it can lead to a shortened service life due to irregular
wear and increased vulnerability to impact and staking.
Tread depths,
too, can contribute to both the economy and safety of operation. We
know the legal minimum tread depth on tyres is shown by the
treadwear indicators placed at regular intervals around the tyre
circumference. These are 1.6 mm in height and tyres are classified
as worn out if below this level. Any further operation of the tyre
past this point exposes the casing to a greater chance of
penetration damage, thereby raising the possibility of losing
retreading capability.
Sufficient tread
depth is obviously vital on wet roads and braking effects. We know
the wet braking distance for a worn passenger tyre with a tread
depth of 1.6 mm can be almost twice as long as for a new tyre with
full tread depth. Truck tyres may not be as significant as this due
to the ground pressures involved, but the principal is the same.
So for your
peace of mind, and your hip pocket nerve, make sure you maintain
your fleet at the correct tyre pressures for your particular
operation. Institute an inflation pressure check around every two
weeks. Ensure all valves (particularly inner duals) are accessible
and operable. Use sealing valve caps. And when a tyre has completed
it's first life, remove it early rather than later thus ensuring a
satisfactory retread is obtained.