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26 Comments Add your own

  • 1. Thomas W Gillham  |  November 19, 2007 at 2:56 am

    This is a great site with lots of good information on tyres but I have been unable to find the actual load and speed details that relate to each load index or speed rating.

    Can you advise.

    regards Tom Gillham

  • 3. dev.s.k  |  February 24, 2008 at 5:26 pm

    Is there any standard testing method for tackness of ply, cap or side wall. If so can u please specify.

  • 4. David Matthews  |  February 26, 2008 at 10:51 pm

    I assume that you refer to the tackiness (surface stickiness) of the components during the assembly stage of the green tyre. The tackiness varies with the composition of the compound, the temperature, the liner or plastic film into which it has been wrapped,and also the humidity. As far as I am aware, there is no industry standard test procedure for this.

  • 5. David Matthews  |  March 2, 2008 at 12:08 pm

    I forgot to mention the age- the time that has elapsed since it was processed, by either extrusion, calendering etc. Tack decreases with time after processing also. Becomes a problem after startuing up after annual vacation for any material carried over the vacation period.

  • 6. Carol Wong  |  February 27, 2009 at 9:10 am

    Hi. I’m just wondering if head honchos in the tyre industy/tyre companies should start a blog? Would it help the industry?

  • 7. SALEEM  |  April 29, 2009 at 7:25 am

    DEAR SIR ,
    STOCK SIZE IS 145/70SR/12

    • 8. David Matthews  |  August 5, 2009 at 10:56 am

      I have to assume that you are in Australia in my reply. (It is the World Wide Web you know.) So you are restricted in what you can fit as alternative tyres to those originally fitted, by your State’s regulations.

      Your original fitment of 145/70R12 has the following dimensions:- Diameter 509 mm, section width 150 mm, on a 4.5 inch wide rim. State regulations will only permit an alternative tyre of this diameter plus 15 mm maximum.

      The 155/70R12 that you quote as a suggested alternative is 523 mm in diameter, has a section width of 157 mm on a 4.5 inch wide rim. So that is O.K. PROVIDED that the extra 3.5 mm each side of the tyre doesn’t foul the steering components, or the body work, so check these clearances first. It will affect your speedo by 2.7% slower.The other two tyres are too big in diameter to fit, and are probably too wide as well.

  • 9. nathan  |  June 9, 2009 at 11:31 am

    hi i have a 2002 npr 300 truck that has dual rear tyres. The outer rear tyres are wearing out a lot faster than the inner ones any ideas what could be wrong?

    • 10. David Matthews  |  August 5, 2009 at 9:20 am

      The only listing I have for an NPR300 with Dual rear tyres is for a tipper truck. All others listed from the mid- nineties have 7.50R16 tyres as single fitment.

      So I have to assume that your truck is a tipper. in which case, the outer duals could be wearing faster due to carrying more than their fair share of the load, or the axle housing is bent, or you work on very highly cambered roads (unlikely), or the truck is “short coupled”, and does a lot of work turning very tight circles (as in garbage disposal work).In the tyre maintenance area, it it is all so easy to check the outside dual tyre pressure, and forget about the insides because it is too hard. However, since they are radials, the rolling circumference of the tyre will be the same regardless of pressure differential- assuming that they are radials of course. If you’ve changed to cross ply, it WILL affect rolling circumference, which will set up a scrub between inside and outside dual tyres, causing different rates of wear. So more information please, and I hope that I’m not too far off the mark so far.

  • 11. Damian  |  July 22, 2009 at 12:26 am

    I recently purchased a complete set of GT Radial Champiro GTX 17″ Tyres for my 1999 Commododore Executive Wagon. The dealer also carried a front and rear wheel allignment however in under 4 months both the insideedges of my front tyres are worn back to metal/wire. Although these tyres have a no ifs no buts 5 yr warranty, the dealer claims the wheel allignment wasn’t set properly and voids the warranty. Has anyone else had a similar experience and is thre an expert that could determine what really would cause these tyres to scrub out so quickly. I do 95% highway driving to work daily.

    • 12. David Matthews  |  August 5, 2009 at 8:23 am

      Strange indeed that both INSIDE shoulders are worn excessively. There are several possible causes, that can only be solved by putting the vehicle on the alignment rack again.
      You can probably rule out a misalignment of the rear axle, as this would cause wear on one inside, one outside shoulder (See Barber pole Wear in “All about tyres”. If due to excessive camber, this should be visible if it’s so bad that four months wear resulted. The car would look “knockneed”. Excessive toe-in could only be checked on the aligner. Truly, if the dealer carried out the alignment, he should be prepared to put it up on the rack and check it out for you.
      That leaves the tyres! A radial tyres rolls around the centreline of the steel belts . If these are placed off centre, then the part of the tyre that is not supported by the steel belts will wear prematurely. This is known as “conicity”. The tyre rolls as though it was a cone on its side. If placed on the car with both tyres off centred belts the same way, then it develops a strong steering pull. If placed with the off-centred belts opposed, then you would never know till they each wear out fast on one shoulder. In the early days of steel radials, this phenomenon was not unknown. Today, it is extremely rare but I suppose it could still happen. It all depends on whether the tyre building machine was set up properly in the first place- requires quality control.

  • 13. Damian  |  July 22, 2009 at 12:29 am

    This site doesn’t already have any reviews/ratings for GT Radial. Can this be added. I’m sure there would be plenty of people ready to comment. I have now had 2 bad experiences with these tyres.

  • 14. Jenni Hart  |  September 15, 2009 at 10:33 am

    Hi, The Continental Tyres- Sport Contact 3 that came with my new EOS TDI, wore out before 15000 km. The report stated that they were scalloped on the inner edges and worn from spirited driving. I take this to mean fast, hard cornering and braking.
    I am horrified. I only do country miles and I am a careful driver with a perfect record and am certainly not a spirited driver.

    Has anyone else had problems with these tyres???

  • 15. David Matthews.  |  October 8, 2009 at 9:42 am

    I can only suggest that you have a look at my reply to 12 above.
    Such wear is quite abnormal, and a reputable dealer should be able to solve the problem for you.It is very easy to blame the tyres, since these are NOT guaranteed by the car dealer, but the tyre manufacturer.It’s called the “flick pass” Feathered wear indicates a mis-alignment of the vehicle. Ask for a full “Four wheel alignment to the thrust line”

  • 16. Lesley Matthews  |  October 15, 2009 at 3:15 am

    I need some advice. I am up for 4 new tyres for my 100 series Landcruiser. Last time just opted for the tyres from factory- Grand Trek and have had no issues got 60,000 km out of both sets. Have been told there are now better tyres in the market. I am looking at either BFGoodrich Long trail or Michellin Latitude cross. Only use my car for long trips to the snow and around town. Which tyres would you say is the better for snow and mileage?

  • 17. David Matthews  |  October 26, 2009 at 12:17 pm

    Reply for Lesley Matthews. The “Grandtreks” seem to be doing a good job, and yes, they were developed for that particular vehicle.
    BFGoodrich are now owned by Michelin, and there has never been a bad Michelin tyre yet. After that, seems you also met a good salesman selling the product he knows. But it’s your choice,and price must influence your decision.

  • 18. Gerald Davies  |  October 27, 2009 at 12:06 pm

    I am buying 4 new tyres for my son’s BMW Z4 so I am shopping around. Why do prices vary so much. I went online and asked for price to be fitted locally and he gave it to me. Then he said if your son contacts me direct, I can offer discount and he can them fitted locally. My logic tells me that if I want the best deal I go in with this quote to the local tyre place and bargain!! But why does life have to be so complicated?

  • 19. Cliff  |  August 7, 2010 at 4:09 pm

    Sticking with Original Equipment Manufacturers?
    Have typically replaced tyres with the exact same type but doesn’t technology improvement mean that tyre choices should be updated as well?

    2002 Saab 9-5 Arc Estate (I am told) is a Good Year Eagle NCT5 Eco 215/55R16 9V but what are my options if I am after a touring tyre with long wear characteristics? Highway driving at 100km/hr for 95% of the time? Should I just look at what the car manufacturers put on their latest models and follow suit?

  • 20. David Matthews  |  September 2, 2010 at 7:24 am

    The Goodyear NCT (neutral contour tyre from memory) is a design about 12 years old by now.
    Most modern tyres from 16 plus inches, have improved designs to give better wet road holding- and that’s a generality if ever I wrote one. Quite often, this improvement comes at the expense of tread wear, either by redesign of the pattern to incorporate wider water channels, or more of them; or by recompounding the tread rubber by incorporating some silica.
    So the improvements may or may not, be what you’re looking for- improved tread wear? But with another 12 years design expertise under their belt, and greatly improved machinery to build tyres on these days, so that they’re “straight”, a more modern design would certainly be worth investigating. Won’t be any cheaper though!

  • 21. David  |  September 10, 2010 at 11:14 am

    Have a look at “GoodTyres Bad Tyres- What’s the difference anyway” in the blog, dated November 2, 2009. Maybe this will help.

  • 22. Ray B  |  September 13, 2010 at 10:50 pm

    I’m an aussie putting together a turn key tyre manufacturing plant in south america,operational by 2012,focus on 13″ & 14″ light passenger vehicle tyres, would like to locate Australian tyre/compound engineer/expert to work with us in an advisory role, any assistance would be greatly appreciated. By the way great info on this site!

  • 23. David  |  September 15, 2010 at 10:26 am

    See my article on “Vale- Australian tyre manufacturing” earlier in my blog. Wth the closure of both Goodyear/ Dunlop, and Bridgestone (Melbne and Adelaide respectively) I would think that you would be swamped with offers. Numbers of Olympic people went to China for an extended period to launch a tyre factory there in the late eighties.
    The articles in this blog are my distilled experience of now over 60 years in the industry, but South America is too late for me. I’d advertise in the Sydney Morning Herald, or “Age” professional columns. You need a compounding chemist, and a tyre development engineer, by the sound of things. I assume you have some technical tie-up to a major manufacturer to supply the basics.

    • 24. David  |  September 18, 2010 at 2:31 am

      Silly old me. Of course there’s the Adelaide “Advertiser” included in the mix. But Carbonblack.com.au also has an employment section on this site. And why not try “Adage” which actively recruits “experienced” workers- read mature age. That is where Carbonblack found me!

  • 25. Oscar Bohorquez  |  February 14, 2011 at 11:42 am

    Hi David, Dunlop SP SPORTER tyres 255-145 Z R18 on my Mercedes CL500 coupe (oldtimer). Tyres are 4 years old and have 5000kilometers on them. The car have not been used for 3 years and the tyres are not roud anymore. I pumped them extra hard but it did not help. What else can I do.
    Regrds, Oscar.

  • 26. David  |  February 23, 2011 at 5:42 am

    The idea would have been to pump them up hard for storage. Now you have to get them to flex , which will make them warm. This will take the thump out of them, which is because the nylon casing is “flatspotting”. So the way to fix it is to deflate the tyres to normal pressure, then take the car for a run for about 20 km, preferably at highway speeds. The out of round will gradually disappear. If it persists, get the tyres rebalanced, but AFTER running them. We call it “morning sickness”, which happens only with nylon casings after they’ve been run, and allowed to stand ( over a cold night generally) If you examine the legend on the sidewalls in small letters, it will read something like “sidewalls 2 plies of nylon”.
    Most ZR rated tyres have nylon casings.There’s nothing wrong with the tyres! You’re a lucky man to have a CL500 coupe-I’ve always lusted after one!


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