Tuesday, Apr 15, 2003 at 23:59
Hi guys,
I have had Cooper ATs and they were great. Now thinking of STs for my Patrol given more gravel work. Last week another thread referred to lug tearing on STs, so I asked Coopers direct. The reply was extremely informative and for anyone thinking of purchasing STs it may pay to wait to mid-year for the STCs (anti-chipping compound).
Feedback like this from the Oz distributor is why I am and will remain a user of Cooper tyres,
Hugh
.........................................................................................................
We have just had a visit from the
technical people from Cooper USA so I am up to date with all the information
about changes in Cooper product etc. As you may be aware Hugh our company
has been the Australian importer of Cooper Tires for 13 years and we work
with distributors in each state as
well as having a retail store in
Brisbane
that specializes in 4x4 tyres. So we have seen a lot of tyres over the years
and all the brands which has given us the ability as a wholesaler to see
first hand the effects of the Aussie conditions on tyres, in fact we have
had input into the design on some of the Cooper patterns in recent years.
The comments you have read on Explore OZ website on Cooper ST's chipping and
tearing of lugs. Yes we are aware of it, and yes it has happened more than
we first expected, however most of the people who experience this and feel
that it excessive, have been comparing to other mud pattern tyres. You see
Hugh the Cooper ST is a unique pattern and is designed to fit between a mud
pattern and an All Terrain pattern and for people looking for more traction
than other All Terrain tyres. The only trade off is that it is still an All
Terrain pattern and does have limitations. What I mean by that is the ST
has Sipes or tiny cuts in the tread blocks. These sipes are designed to
squeeze water out form under the tyre on the black top, however on sharp
dirt roads the tyre chips away as it does with all siped all terrain
patterns. It is just that people think that it should not chip, however
whenever we have seen a direct comparison between a Cooper ST and other
brands of AT patterns the ST does better
miles in the long run and does chip
less in the same conditions.
Remember that the mud patterns do not have sipes (even the Cooper Mud
pattern) and that's why Mud pattens do not chip and do better in sharp or
gravelling conditions. Also remember that many people that should be using
mud pattens for these reasons and have switched to Cooper ST's to reduce
tyre noise and improve on road performance have been the ones to notice the
difference. (many of these people that come through our retail outlet we
have changed back to Cooper STT's and they have now realised that their
application does require the Muddy's)
Tearing lugs is for similar reasons. The Cooper ST has a small but sharp
shoulder lug with a fine split or sipe in the middle of it and if you
compare with the Cooper Mud pattern in the same size the Mud pattern lug is
at least 3 times the size.
It is obvious to us now why the ST lugs tear. Put simply, they are doing the
job. What I mean is they are getting traction, to much traction, and because
of the small lug they can tear. Now when given the same condition with a
Muddy they don't tear and get the same grip, whereas if the same tyre had of
been an All Terrain pattern it may have not torn, however it also would not
have griped like the ST. (they probably would of got stuck) The people that
buy the ST for more traction than the average AT have been happy, it has
only been the Mud tyre buyer that has bought ST's or people that use them
for the same sort of work that have concerns.
Now the good news as some people have heard is Cooper are improving the ST
compound. In late may we are expecting our first shipments of the new
compound. (the pattern name with be STC standing for Chip Resistant) Now all
tests show a huge improvement with a 90% improvement in tear resistance and
40% improvement in chip resistance. Remember Hugh that although it will be
improved it will still chip as the sipes are still in the design as
well as
the small shoulder lugs, so it will be far better that any other All Terrain
but still not as resistant as a Mud pattern given the same conditions.
If you would like to discuss this further please feel to give me a call toll
free on 1800 681 298
Thankyou for your inquiry
Robert Keilar
P.O. Box 101
Moorooka Qld 4105
Australia's 4WD Tyre Specialists
Phone: 07 3272 9888
Fax: 07 3272 9588
e-mail. robertk@exclusivetyres.com.au
AnswerID:
17740