Spare
tyres are not included in the inspection. However, if a defect
is seen, the owner should be notified.
The owner should be advised of loose or missing security bolts.
Serious under-inflation of tyres is not a reason for failure.
However, the tester may decide not to conduct a brake test if
tyre damage is likely, or a headlamp test if alignment could
be affected. Advise the owner.
A tyre repair may be drawn to the attention of the presenter.
Examples of unsuitable tyres:
a. side car tyres or car tyres on a solo machine (note side
car outfits may be fitted with 'solo' type tyres on any wheel);
b. Motocross or similar tyres, i.e. tyres where the space between
tread blocks is substantially greater than the size of the blocks
themselves; which do not have MST (multi service tyre) with
an 'E' in a circle or an e in a rectangle moulded into or on
to the tyre wall
c. tyres designated by their manufacture as unsuitable for road
use e.g. racing tyres or those marked NHS or NOT FOR HIGHWAY
USE on the sidewall.
d. a tyre specifically designed for front wheel use fitted to
the rear wheel;
e. a bias belted tyre fitted to the front with a cross-ply tyre
fitted to the rear wheel
f. a radial tyre fitted to the front and a cross ply or bias
belted tyre fitted to the rear wheel
On radial tyres care should be taken to distinguish between
normal manufacturing undulations in the carcass and lumps or
bulges caused by structural deterioration.
Where the engine capacity is not greater than 50cc, tread depth
may be less than 1 mm, if the tread pattern is clearly visible
around the entire circumference and across the whole breadth
of the tread.
Directional tyres these tyres must be fitted in accordance with
the instructions on the sidewall. The direction of forward rotation
is indicated by an arrow, words or both.
Tyres which do not meet the three-quarters width rule when new
must have a minimum of 1 mm tread over the whole of the original
tread pattern.
'Breadth of tread' means that part of the tread which can contact
the road in normal use. Including cornering.
'Tread pattern' excludes tie-bars, tread wear indicators, features
designed to wear out substantially before the rest of the pattern
and other minor features. Original tread pattern must be taken
into account when assessing tread wear.
The position of tread wear indicators
are normally marked TW1 on the side wall of the tyre in line
with the tread wear indicator-
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1.
Examine the tyres for type and suitability. (see information
column)
2. With the wheels raised clear of the ground, rotate each slowly
and examine each tyre for:
a. cuts. lumps, bulges, tears or exposure of the ply or cord,
separation of the tread
b. incorrect seating in the wheel rim
c. valve condition and alignment
d. recutting of the tread
e. fitment in the correct direction of rotation
3. Check that there is a visible tread pattern around the complete
circumference of the tyre- Ensure that the tread depth meets
the requirements using a depth gauge.
4. Check for signs of fouling of tyres on other components.
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1.
An unsuitable tyre.
(see information column)
(i) A tyre has a cut longer than 25mm or 10% of the section
width of the tyre. whichever is the greatest, and deep enough
to reach the ply or cord.
(ii) A tyre with a lump, bulge or tear caused by separation
or partial failure of its structure, including lifting of the
tread, (see information column).
(iii) Any ply or cord exposed
b. a tyre not correctly seated in the wheel
rim
c. a seriously damaged or misaligned valve stem which could
cause sudden deflation of the tyre
d. a tyre with a recut tread
e. A tyre not fitted in accordance with the direction of rotation
marked on the sidewall (see information column).
3.
(i) the tread pattern is not clearly visible over the whole
tread area. (see information column)
(iij The depth of tread is not at least Imm throughout a continuous
circumferential band measuring at least three quarters of the
breadth of the tread, (see information column).
4. A tyre fouling another component
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