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
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
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
The position of tread wear indicators
are normally marked TW1 on the side wall of the tyre in
line with the tread wear indicator-
Examine the tyres for type and suitability. (see information
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.
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
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).
(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