TYRE
REPLACEMENT
Tread
depths should be checked regularly, tyres carry tread depth
indicators which show whether a tyre is reaching its wear limit.
At low tread depths, the risk of skidding on wet surfaces is
increased.
In the case of replacing two tyres, for the best handling it
is best to fit the new or least used tyres to the rear axle.
If used tyres are fitted, always consult a professional.
For safety reasons, it is recommended to fit a new tube with
a new tube type tyre and a new tubeless valve with a new tubeless
tyre.
Tubeless tyres should only be fitted to suitable tubeless type
wheels.
MIXED
FITMENTS
Except
in particular cases such as the use of a temporary spare tyre,
tyres fitted across an axle must be of the same size and type.
It is not recommended and even illegal in some countries to
fit bias-belted or cross-ply tyres to the rear of a vehicle
if radial tyres are fitted on the front.
FITTING
THE TYRE ON THE WHEEL
As
a general rule, Michelin advises placing the side marked “DOT”
(near the bead) towards the outside of the wheel.
(Except for:- directional tyres Whitewall tyres Tyres
with a protector on the sidewall)
- A tubeless tyre should be fitted without a tube on vehicles
fitted with the correct tubeless type wheels
(hump, flat hump etc.)
- It is strongly recommended that tubes are NOT fitted to a
tubeless tyres fitted on the correct tubless
type wheels (hump, flat hump etc.)
- Should it be necessary to use a tube with this combinations,
inflation must be undertaken slowly to facilitate
the evacuation of any air trapped between the tyre and tube.
Michelin does not recommend to
fit tubes in low profile tyres.
- A tubeless tyre (80 and 70 series) fitted to a tube type wheel
(straight taper, flat edge, reversed etc.)
must be fitted with a tube.
- A tube type tyre fitted to either a tubeless or tube type
wheel must be fitted with a tube.
- Fit a new Michelin tube with a new tyre.
- For tubeless fitments, use the correct valve for the wheel.
A new valve ( or new joint in the case of
metal valves) should be fitted with each new tyre.
- After fitting, inflate car tyres to 50 psi to correctly seat
the beads and then reduce to the working pressure.
Modern
air lines allow rapid inflation to high levels.
On these airlines set the regulators to :
- 60 psi for car tyre inflation.
- 70 psi for utility vehicle tyre inflation.
FACTORS
AFFECTING TYRE LIFE
As
well as the factors already listed, a tyre’s life can also
be affected by a number of other things ;
- Speed and conditions of driving : twisty roads, frequent acceleration
and breaking put constraints on tyres
that can considerably effect their wear (a tyre running at 120
km/h wears twice as fast as one running
at 70 km/h ).
- Ambient temperature : tyre wear is also affected by temperatures
under which the tyre is used.
- Overloading : a tyre overloaded by 20 % will lose 30 % of
its potential life.
- Under-inflation : a tyre under inflated by 20 % will lose
on average 30 % of its potential life.
- Shocks : kerbing, hitting potholes at speed, stones and other
obstacles can all be the cause of a tyre’s
deterioration. Often with the consequences not becoming
immediately apparent.
- Pressure differences A: difference between twinned tyre pressures
can cause severe damage.
