Triumph Spitfire MK3, Handbook

Page: 26 / 81

WHEELS AND TYRES
25
Excessive wear in the centre of the tread (Fig. 41) results from
over-inflation, in which condition the fabric is more easily damaged.
Excessive wear at the outer edges of the tread (Fig. 40) results
from under-inflation, a condition which causes excessive heating
and premature tyre failure.
Tyres
Adjust tyre pressures in accordance with the recommendations
given below.
NOTE. Maintenance of the pressure differential between front and
rear tyres is essential for correct steering behaviour.
Never bleed a warm tyre but always adjust the pressure whilst
the tyres are cold, i.e. before a run. As the tyres warm up their
pressures will increase.
To prolong tyre life, avoid severe braking, sudden changes of
direction at speed, and driving over or against high kerbstones, as
this can result in severe damage to the tyre walls. Examine the tyres
occasionally and remove flints or other road matter which may have
become embedded in the treads. Clean off any oil or grease which
may be on the tyres by using a cloth moistened in petrol.
Repairs to Tubeless Tyres
A temporary repair can be made to tubeless tyres using a special
kit, provided the puncturing hole is small and confined to the central
tread area.
The following precautions must be observed:
1.
Do not use more than one plug in each hole.
2. Do not use the tyre for high speeds.
3. Ensure that a permanent "cold patch" or vulcanised repair
is made at the earliest opportunity.
RECOMMENDED TYRE PRESSURES
FRONT REAR
Tyre Size and Type Psi Kg/cm
2
Psi Kg/cm
2
5.20 S – 13 .. 18 1.26 24 1.69
1.45 – 13 Radial ply .. 21 1.47 26 1.83
Where maximum performance is regularly used or if the vehicle
is tuned to increase its maximum speed, radial ply tyres are
recommended. They are satisfactory at the pressures given
above, up to a sustained speed of 110 m.p.h. (176 k.p.h.).
For sustained speeds above 110 m.p.h. (176 k.p.h.) consult
the respective tyre company regarding the need for tyres of full
racing construction.