Tyres
 In
radials tyres the ply or ply cords are alligned at 90 degrees to the
circumference. While radials improve performance the fact is that they
are not very good for bad roads and overloading. The suspension of a
vehicle has, also, to be modified to accept radials. Radials offer much
better grip of the road especially on surfaces which offer poor wheel
traction like wet of slippery roads.
What do treads on tyres do?
Treads perform a variety of functions which includes increasing road
grip, cooling the tyre while running at high speeds, forming an effect
whereby tyres with deeper treads may not pick up loose pebbles and nails
on the road, and providing a safe margin of rubber before the complete
tyre wear out. In wet conditions they provide ducts through which the
water is squeezed out. This in turn helps the tyre grip better.
Maintenance of Tyres
The single greatest cause of tyre damage is improper inflation, which
result in unnecessary stress on them and also poor fuel average. Ensure
that tyre pressure is always correct. At least once in every two weeks
the tyre pressure should be checked and also when they are cold. Hot
tyres will reflect wrong pressures and these will reduce once the tyre
gets cold. Make sure the spare is always pressed up correctly, too.
Rotate tyres regularly, as per the owner’s manual. Remember that
some tyres are designed only for uni-directional movement and others
have specific front/rear location rolls. By and large on general
vehicles, the tyre rotation pattern is criss-cross.
Taking out small stones and pebbles from the treads is also a must. As
far as possible, overnight parking should be on hard surfaces. Waste or
stagnant water on the streets is usually very corrosive and will eat
through the sidewalls.
The best way to safeguard your tyres and give them a long life is by
using your right foot carefully. Hard braking or sudden jerky racing
starts finishes a tyre faster. Spinning the wheel is another disaster
for tyres. Refrain from turning the front wheel while the vehicle is
stationery. This also causes excessive wear.
Regular visual inspection is a must, both from inside and outside. Look
for cracks, bulges, cuts and odd wear and tear. If you find uneven wear
and tear, it may because of bad alignment. This can reduce tyre life
drastically, as it causes irregular tyre wear. Avoid overloading of your
vehicle. Never exceed the road limit of your vehicle.
What do the alpha-numerics on the side of the tyre denote?
Ordinary tyres will have rating like 5.65-12 (as in the Maruti 800).
This means the actual cross section on the tyre (in inches) when mounted
on the rim (5.65) and normal rim diameter in inches (12). You may also
see other number which signify month and year of production, serial or
batch number of production line and ply ratings, which simply implies
stronger carrying strength.
Radial tyres are marked with numerals, for e.g. 145/70 R 13 T. This
means that the 145 (MM) stands for tyre width, the ‘R’ stands
for Radial. 70 (MM) is a profile on the sidewall of the tyre. This is
the diameter of the wheel with the tyre minus the diameter of the rim.
13 (inch) is the diameter of the rim. The last alpha(T) signifies the
permissible speed or performance rating of a particular tyre. |
