| From: Roger Parker Tamworth roger.parker@virgin.net on 25/10/1998
Cars and light vans have to have a MINIMUM of 1.6mm depth of tread in an
uninterupted band for the full circumference of the tyre. This band must cover
the 'central three quarters' of the tread. In simplistic terms this
means that if the tread width is 6" (measured shoulder to shoulder) then the centre
position is 3" in. Either side of that centre line must be 2.25" of the tread width
with the minimum depth of tread. The remaining 3/4" on either side does not have to
have any visible tread left, but must not show wear down to the understructure of the
tyre.
Motorcycles, large goods vehicles and large passener carrying vehicles
(lorries, bus and coaches) have different rules. (the old rules actually) They must
have at least 1mm of tread depth for at least 3/4s of the tread width. This 3/4 can
be achieved in many ways, from one side or the other, or accumulated through two bands
either side of a worn centre. Unlike the other regs the remaining tread area HAS to
show visible tread even though it is below 1mm. The above conditions have to apply to
the whole circumference of the tyre.
The anomoly was created when the 1.6mm tread law was introduced as the legislators
either forgot, or planned other legislation which has not arrived. This means we have
two completely different rules for different types of vehicle.
Whilst this affects those who have cars and bikes I would point out that anyone who
has reached these sorts of tread depths is way beyond the point where the tyres
performance, especially in the wet, has deteriorated very, very significantly. 3mm
should be regarded as the change point for tyres on cars.
Rog
From: Darren, Northants on 23/10/1998
MGF Tyres have tread wear indicators, too, so you can tell from them if they need
replacing. |