Truck & Driver UK – August 2019

(^48) Summer 2019 Truck & Driver
Barron, who has been
working at Strang for
over 20 years. The
company has depots in Hamilton,
Broxburn, Dundee and Irvine and
offers a full mobile tyre fitting
service for trucks, including
24-hour breakdown and fleet
inspections.
How old are
your tyres?
You may have noticed in the
press some news about the
DVSA tightening its guidance on
the age of tyres, spotlighting
tyres over 10 years old.
Independent research on older
tyres is due to be published this
summer. Until then, it’s not an
MoT fail if you have one on your
vehicle providing it’s in good
condition, but you’ll be asked to
explain about the tyre and your
maintenance programme.
Michelin does not recommend
using tyres of this age on any
vehicle’s steer-axle though.
To check the age of your tyre,
a four-digit code is stamped on
the sidewall; this may be prefixed
by ‘DOT’, which is an American
marking and has no bearing on
regulations here in the UK. The
four digits will be the week of
production and the year, so 1217
is week 12 of 2017.
Retreads &
regrooving
Retreading a tyre is an important
part of a tyre’s overall lifespan. A
new Michelin tyre can potentially
have as many as six ‘lives’, as
follows: new; regrooved;
retreaded as a Remix; regrooved;
retreaded as an Encore; and
regrooved for a final time.
Regrooving a tyre ideally
should take place when the
remaining tread depth is 3-4mm.
At this point the rolling resistance
is at its most efficient and an extra
25% is added to the tyre’s life.
The vast majority of Michelin’s
retreads are manufactured using
the bead-to-bead process, where
a new sidewall and tread is fitted
to the casing. A very small
number of its retreads are made
by using the cold-cure process,
where the old tread is buffed off
and a new one fitted to the
original sidewalls. The date of
manufacture or remanufacture
will be stamped on the sidewall
as per a new tyre.
Michelin does not recommend
the use of retreads on the front
steer-axle. It’s recommended that
you use retreads from the same
manufacturer across an axle,
although you can move a set of
regrooved steer-axle tyres onto a
midlift or tag-axle.
Tyre labels
You’ll have seen the labels on
car tyres advising the wet grip,
economy and noise ratings. The
same categories apply to truck
tyres, you just don’t get a label;
the info is available online and
your tyre service agent should
make you aware. In terms of wet
grip, the difference in stopping
distance from one category to
the next is 4.5m. It could
be as little as 10cm from
the lowest point in one
BFGoodrich is a recent entry to the European truck tyre market
Regrooving and retreading gives tyres multiple lives