winter stud tyre - snowtyres.com.au · while practical terminology will be used throughout the...

WinterStudTyreTestReport

GlennBillmanMtHothamRoadPatrol20/09/2017

TestReport MTHOTHAMROADPATROL

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Introduction

This report has been compiled and written by the Mt Hotham Road Patrol operator and has beenproduceddueto the increasing interestgenerated fromtheWinterTyreTestReportof2015.To fullyappreciate this report the reader shouldavail themselvesacopyof the2015WinterTyre test report,thiswouldprovideavaluableinsightandunderstandingoftheconditionsandissuesexperiencedontheroadsinthealpineregionsofAustraliaduringthewintermonths.WhilethisreportistitledWinterStudTyreTestReportitwillcoversomeofthepertinentinformationfromthepreviousreport(WinterTyreTestReport,2015).The informationprovided in thisdocumenthasbeencompiled fromobservations,extensiveexperimentationandtestingconductedalongtheGreatAlpineRoadatMountHothambytheMtHothamRoadPatrolduringthewintermonths,overaperiodof17years.TheMtHothamRoadPatrolbeganoperation in2001 to service thehighnumberofmotoristshavingdifficulty on the Great Alpine Road due to the severewinter road conditions experienced. The RoadPatrolprovidesafree24/7servicetoalldistressedtravellersontheGreatAlpineRoadduringthewintermonths.InprovidingthisservicetheRoadPatrolhastravelledinexcessof221,000km’sinalltypesofweatherconditionsandonall typesofwinter road surfaces. Informationandknowledgehasalsobeengainedfromover370seriousvehicle incidentsandmanymoreminorvehicle incidentsexperiencedalongtheGreat Alpine Road. Extensive research from Australian and especially overseas documentation hasprovided great insight into other countries’ solutions and legal requirements to help prevent vehicleincidentsandissuesoniceandsnowcoveredroads.Whilepracticalterminologywillbeusedthroughoutthereport,technicalterminologymaybeusedbutwillbekept toaminimum. It shouldalsobenoted that if anyvehiclenameormodelappears in thisreportitisnottoberegardedasanendorsementoracriticismofthatvehicle.Thetestingofthewinterstudtyresinthisreportwasconductedduringthe2016-17snowseasonswiththetyresbeingfittedtoa2006ToyotaLandcruser6cyl4.2turboDiesel,approximateweight3000kg.ThetyrestestedinthisreportareNokianHakkapeliittaLT2,StudTyresize265/75/16.ThemethodoftestingwasinthenatureofgeneraldrivingthatwouldbeexperiencedbyallmotoristsandintheeverydayoperationaldutiesoftheRoadPatrolservice.Thiswouldincludebutnotbelimitedto, traction testing around corners, braking,movingoff onuphill sectionsof the road, traversing softsnowandtowingloadsinascendinganddescendingsituations.Whilethisreportiswrittenwiththeexperiencedalpinedriverinmind,itcouldbeavaluableresourcefornewdrivers’planningtodriveinthealpineregionsofAustraliaduringthewintermonths.



VictorianAlpineRoads

MountHotham

TheGreatAlpineRoadbetweenHarrietvilleandOmeotraversessomeofthestate’smostpicturesquealpine sceneryandnestledbetweenHarrietville andOmeo is thealpine resort villagesofMtHothamandDinnerPlain,bothofwhichareextremelypopulartouristdestinationsespeciallyduringthewintermonthswhentheroadisoftencoveredwithsnowandice.

ThissectionofroadisfullysealedandpassesthroughtheMtHothamVillageandDinnerPlain;theroadrisestoanaltitudeof1,840metresandissubjectedtoconsiderablesnowfalls,blizzardsandhighwinds.ThissectionoftheGreatAlpineRoadalsoregularlyexperiencestheformationofBlackIce.BlackIceisformedbya thin layerofwater freezingon the surfaceof the roadandhas theappearanceofawetroad.

BlackIce.

Theroadhasnumeroussharpcornersandsteephillsthatcanbecoveredwithmanydifferenttypesofsnowandiceatanytimeofthedayandnight.Theextremeweatherconditionscananddosometimesresult in the road being closed between Harrietville and Omeo due to heavy snow and other safetyconcernsbyauthoritiesandwhilethismaybeinconvenientforsomemotoristsitissaferforall.

In today’smarket a variety ofmotor vehicles are used by tourists, travellers, skiers andworkers andwhiletheroadisutilizedallyearrounditisthewintermonthsthatcausesmostofthesafetyconcerns.In recentyears therehasbeena considerable increase in theAll-WheelDrive (AWD)andFour-WheelDrive(4WD)vehiclesfrequentingthealpineregionsbutunfortunatelytheyarealsothemostcommonvehiclesinvolvedinvehicleincidentsontheroadduringthewintermonths.



TheVehicles

Vehicle manufactures are offering more sophisticated AWD and 4WD systems than ever and theadvancements in this area are in many ways good news for car buyers looking for off-roadvehiclecapabilities. There can also be a lot of confusion, especially with the growing number of differentoperatingtechnologiesutilisedacrossdozensofmanufacturers.Formanyyearstoomuchemphasisandreliancehasbeenplacedonthetypeofdrivesystemthevehicleemploysby theretailers,advertisersandtosomeextenttheenduser,buttheoneissuethatneverseemstobeaddressedistheimportanceoftractionwiththeroadsurface.

InorderforanAWDora4WDsystemtoworkasthevehiclemanufacturedesignedittoitmusthaveorthecapabilitytohaveallfourwheelsnearequaltractionwiththeroadsurface.Nomatterwhattypeofdrivesystemthevehicleemploysifthevehiclelackstractionwiththeroadsurfaceinicyconditionsthevehicleisnothingmorethanabigexpensivesled.

ItshouldalsobenotedthatmostoftheAWDand4WDvehiclesontheroadtodayareofanoverseasoriginandthereforedesignedforanoverseasmarket.Itisassumedbythemanufacturethatthepeoplebuying their vehicles to be driven in alpine conditionswill be experienced enough to understand therequirementstodriveonsnowandicecoveredroadsandtoabidebythelawsofthatcountry.Howeverthevehiclesareoftenexportedtocountriesallaroundtheworld,includingprimarilydrycountrieslikeAustraliawerealpinedrivingisnotwidelyappreciated.

InAustraliamost retailersand salespersonnelhave little knowledgeorexperienceofdriving in snowand icy conditions and therefore fail to pass on pertinent information to the purchaser, even to theextentof giving thebuyer incorrect information.Notmanymotorists readorunderstand thedriver’smanualthat issuppliedwiththevehicleandsometimestheinformationthesalespersonnelhavetoldthemotoristisincontraventiontothemanual.Thisoftenleadstothemotoristbelievingthattheyknowalltheyneedtoknowforasafeandcarefreejourneytothesnow.Butthisleadstocomplacencyandthisiswhenthejourneycancometogrief.

MostoverseasmanufacturesofAWDand4WDvehiclesrecommendthefittingofsnowtyresduringthewintermonthsandassumemotoristswillcomplywiththeinformationprovidedintheirdrivers’manual.Inmanycountriesthatexperiencesnowitismandatorybylawthatsnowtyresarefittedtoallvehiclesforthedurationofthewinterperiodandheavypenaltiesapplyfornon-compliance.

Inoverseascountriesthatexperiencesnowthevehicleandtyremanufactureshaveinvestedbillionsofdollarsinresearch,developmentandtesting.Thevehicleshaveamultitudeofdifferentbuttons,knobsandsensorstoassistwithtractioncontroltokeepthevehicleoperationalandtheoccupantssafeontheroadbutthevehiclemanufacturesalsoknowthegreatimportanceoftractionwiththeroadsurfaceinsuchconditionsforthesystemstoworkasdesignedandthereforepresumethattyressuitablefortheconditionshavebeenfittedtothevehicle.



HighwayTyres

ThemodernhighwaytyresavailableinAustraliaaredesignedandmanufacturedtobeusedspecificallyonAustraliandryorwetpavedroadstoimprovehandling,fueleconomy,safetyandcomfort.Thistypeof tyre is made of a hardwearing rubber compound that is designed to withstand the highertemperaturesexperiencedonAustralianroads,whileimprovingthedurabilityandlongevityofthetyre.Thehighwaytyre is themostcommontypeof tyre fittedtovehiclesandthis includesmostAWDand4WDvehiclessoldinAustraliatoday.

ThemajorityofAWDand4WDvehiclesontheroadtodayaredrivenonsuburbanroadsandarerarelydriveninsnoworoffroadconditionsthereforemostlystandardhighwaytyresarefitted.Highwaytyresservicethevehicleanditsoccupantsextremelywell,afterallthatiswhattheyaredesignedfor.

However if an AWD or 4WD vehicle fitted with highway tyres is required to travel in snow and icyconditionsthetyre’stractionandsafetycapabilitiescanbeseverely limitedandthiswillcontributetopoor vehiclehandling and/orpossible lossof control. The rubber compoundused in this typeof tyrewhenbelow10degreescanbecomehardandworkspoorlyatprovidingtractionwiththeroadsurface.Italso lacksamplecrossgroovesoradequatesipeingandthis inturncompromisesthetyresabilitytoperformwellinfrigidconditionsorretaintractiononasnoworicecoveredroadresultinginthevehiclebecomingincapacitatedontheroad,blockingtrafficorfailingtobeabletostopwhenrequired.



The photographs on page 5 are of four different AWD and 4WD vehicles fitted with road worthyhighway tyres. Threeof the four vehicleswere involved in road incidents requiring thevehicles tobetowedfromtheMountaintheotheronewasparkedinamountaincarpark.All fourvehicleshadlessthansuitabletyresforsnowandiceconditionsandnoneoftheabovevehicleswereatthetime,bylawrequired to fitwheel chains. Tohelpovercome the lack of traction issue, drivers are instructed to fitwheel chains by the Authorities. This decision is categorised by the type of drive system the vehicleemploysandnotthetractioncapabilitiesthetyres.

To exacerbate the situation, advertising and marketing companies promote AWD and 4WD vehiclesdriving on snow covered roads or across snow covered plains doing all kinds of vehiclemanoeuvreswithout any issues. This has a tendency to portray to the onlooker that the vehicle in question isinvincible in snow and ice conditions and is the safest and most dependable vehicle that they canpurchase.Thisismoreorlesstruebutwhatisnotmadeobviousorhighlightedtotheonlookeristhatwith the exception that the driver is an extremely experienced snowdriver the vehicle ismost likelyfittedwithgoodqualitywintertyres.

Thiscanbeanhonestoversightbyadvertisers inAustralia,asmostof thevehicleadvertisementsarefilmedandproducedoverseasandarepresumablylicensedtobeusedworldwide.Afterallitisnottheadvertisers’ responsibility to know if the product they promote works or not. Unfortunately theconsequences of this oversight and the drivers’ belief that they have all the necessary skills andequipmenttodriveonsnowandicecoveredroadscanleadtocatastrophicoutcomesforthedriverandotherroadusers.



WheelChains

WheelChainsorSnowChainsaretractiondevicesthatarefittedtothedrivewheelsofvehiclesthatarerequiredtotraverseoversnowcoveredroads.WheelChainsorsimilartypesoftractionmethodshavebeenusedonvehiclesforwellover100yearsandhavehadmanychangesindesigninthattimebuttheprinciplehasremainedthesame,toprovidetractiontorubbertyresinslipperyicyconditions.

Itshouldalsobenotedthatwhenwheelchainsfirstcameontothemarketplace,vehiclesofthedayhadlesstorque,lesshorsepower,narrowwheelsandamajorityofroadswerestillgreatlyunpavedandchainsthereforegainedtractionfromthecompactedsnowaswellasthesurfaceoftheroad.

Inorderforwheelchainstoworkeffectivelythechainlinksmustpenetrateintoacompactedsurfacethat has enough integrity to prevent the wheels from spinning when power is applied to the drivewheelsofthevehicle.ThisismuchthesameprincipleasaBulldozercleatondirtbutunlikeaBulldozertrackwithcleatsthatspreadstheweightsofthemachineoverawideareaawheelfittedwithachainwillhaveatendencytospininsoft,looseordeepsnow,diggingaholerenderingthevehiclebogged.

In thepast thebestandsometimes theonlyalternative to improvevehicle tractiononsnowcoveredroads inAustraliawas the fittingofwheel chainsbut theyhavenotbeenwithout their issues.Wheelchainsaregenerallyonlyfittedtothefrontorreardrivewheelsofavehicleandwhilethiswillprovidedrivetoavehicle,itwilldolittletoimprovethehandlingofthevehicle.Itshouldalsobehighlightedthatwheel chain performance is greatly improved if fitted to a winter tyre as is the custom in overseascountries that experience heavy snow. This allows the wheel chain to assist the tyre if needed asopposedtothewheelchainbeingfittedtoahighwaytyreandthechainbeingreliedontosupplytheonlyformoftraction.



Good qualityWheel Chains should be constructed from high quality steel and in a diamond patternconfiguration across theentire treadwidthof the tyre.Wheel chainsprovide tractionbybeing fittedaroundthetyreofthedrivewheelsofavehicletoactasanaggressivetreadthatisabletogainleverageincompactedsnowandiceandbeabletoclearitselfofsnowasthewheelturns.

It also needs to be appreciated that as mentioned, the vehicles in the past had less torque, lesshorsepower compared to the vehicles on the road today.Modern vehicles have a lot more torque,horsepowerandareheaverandthis inturnplacesa lotmorestressonthewheelchainsandthiscancontributetothechainsbreaking,damagetovehiclesandvehiclesbeingleftincapacitatedontheroadwaitingforassistance.

InAustraliaduetothelackofregulationsandofficialstandardsamultitudeofinferiorandinappropriateproductsareonthemarketandtheseproductscananddocauseproblemsformotorists.Wheelchainsshouldonlybepurchasedorhiredfromareputabledealerthatexpertlyfitsanddemonstratesfittingtothe vehicle in question and always consult the drivers’ manual in regard to correct wheel size andcorrectwheelstobefittedwithchains.

Theabovephotosareofatractiondeviceremovedfromavehiclein2017atMtHotham.Thisisadevicethatiscurrentlybeingadvertisedontheinternetandisnothingmorethanaplasticcabletiewithknobson it to serveas cleats. It is fitted to thewheelbyplacingeachone through thewheelandpulling ittight. This product is not suitable forAustralian alpine conditions or legal underVictorian regulationsandmustnotbeused.



TheabovephotosareoftractiondevicecalledtheSnowGloveoranothernameforasimilarproductisSnow Sock. These items fit over the drivewheels of the vehicle a little like fitting a shower cap. TheproductintheleftphotowastestedinthepastatMtHothamunderVicRoadsregulations.Itwasmadefromaclothbasedmaterialandbegantodisintegrateafterapproximately4kmofnormalroadtravel.

Buyerbewaretherearemoreunsuitable, inappropriate,poorqualityandjustplaindangeroustractiondevicesonthemarketthantherearegoodqualitytractiondevices,ifunsureconsultyourpreferredskiresortforadvice.

Most countries that experience snow use wheel chains in one form or another but most of thesecountries have extremely stringent regulations on the use of winter tyres. It is mandatory that allvehiclestravellingonsnowcoveredroadsorincertainareasmusthaveapprovedwintertyresfittedandthesevehiclesmaystillberequiredtofitchainsbylaw.

Inorderforwheelchainstoworkeffectivelytheymustrelyonthetreadandrubbercompoundofthetyretoprovideacertainamountofgripandtractionwiththeroadthishelpspreventthewheel fromspinningwithincertainthechain.Itshouldalsobenotedthatwheelchainsarefittedtoassistthetyretomaintaintractionandarenotdesignedtoprovidetheonlysourceoftractionforthewheel

WheelchainsdonotworkefficientlyonstandardAustralianhighwaytyresandiffittedtohighwaytyresthewheelshaveapredispositiontoover-spinwhenaccelerationisapplied.Thiscancausevehiclelossofcontrolandcontributestothedestructionoftheroadsurfaceandiftheroadiscoveredwithcompactedsnowexcessivewheelspinwillchurnthesnowuptothepointthattheroadsurfacewillresembledeepbeachsand.Inthissituationvehicletravelismadedifficultandvehiclescanbreakwheelchainsandendupincapacitatedinthemiddleoftheroadblockingtraffic.


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Theabovephotoisofdeepcompactedsnowchurnedupbyexcessivewheelspinonanuphillsectionoftheroad.

Blackicecanalsocontributetovehicleissueswhenwheelchainsarefitted.Vehiclesinthissituationcanexperience excessive wheel spin particularly when travelling uphill or moving off from a stoppedposition.Thisisduetotheicebeingtoothintoofferanyresistanceforthechaintogainpurchaseandcombinedwiththevehicle’sweightwithincreasedaccelerationthewheelswillspinandsparkscanflyfromthesteelchainsandthenthechaincanbreakandthiscanhappenwithinsecondsdependingonthedriversexperienceorinexperience.Blackicealsohasatendencytomakebrakingdifficultandwheelchains may contribute to the problem if the driver over estimates the chain capabilities to providetraction. Steel chain on frozen asphalt can slide; this is dependent on the speed and weight of thevehicleanddriverexperience.

Themodernvehiclesoftodayareoftendesignedwithmanydifferenttypesofsensorysystemstoaidinthecontrolandhandlingofthevehicle,oftenknownasatractioncontrolsystem.Butforthetractioncontrolsystemofavehicletoworkasdesigned,thevehicle’sallfourwheelsmusthavethecapabilitiestoachieveanequalamountof tractionwiththeroadsurface.Thiscanbeproblematical if thevehiclehas little chanceof obtaining tractionwhich is often the case if fittedwith highway tyres or ifwheelchainsare fitted toone setofdrivewheelsonly.Withouta certainamountof tractionwith the roadsurfacethesesystemscanberendereduselessandsometimesdangerous.

Wheel chains canalso contribute to vehicleswith traction control systems tohaveoperational issuesdue to the differential between the chained wheels circumference and the unchained wheels. Thechained wheels circumference is increased and this has a tendency to confuse the traction controlsystem and this in turn can become detrimental to the handling of the vehicle. Many drivers havereportedthattheyhadnocontroloftheirvehiclejustpriortocollidingwithasolidobject.Someowner’smanualsstatethattractioncontrolsystemsshouldbeturnedoffwhenwheelchainsarefitted.



WinterTyres

WinterTyres(alsoknownasSnowTyres)havedeepertreadpatternsspecificallydesignedtocompactand grip on to snow to provide traction. Winter tyres are made from a softer rubber compoundcomparedtoothertypesoftyresonthemarket.Thisallowsthewintertyretoretainflexibility incoldconditionsandinconjunctionwiththemanysmallserratedgroovesknownassipesandsipeactivatorsprovideextratractioninsnowandicyconditionscomparedtoHighwayandAllTerraintyrescommonlyfittedtovehiclestoday.Thewidersipeactivatorslocatedonthesideofthetyreassistsinopeningthenarroweronesthusprovidingtractionwiththesnow.

WinterTyre

InAustraliaWinterorSnowtyresarerelativelyunheardofandmostAWDand4WDvehiclestravellingtothesnowarefittedwithstandardhighwaytyresor inregardto4WDvehiclessomemayhavelargelugtypetyresfittedbuttheytoocanbeproblematicinsnowandiceconditions.

WintertyresareidentifiedbyM+Sand symbolonthesidewallofthetyrehoweverwintertyresareoften confusedwith All TerrainM+S (Mud& Snow) tyres however there is a considerable differencebetweenthetwo.

Winter tyres are designed andmanufactured specifically for snowand ice and canprovide enhancedbrakingperformanceinsnowandicyconditionscomparedtoothertypesoftyres.Theyperformwellinall typesofwinterconditions includingsnow, ice,sleet,slush,wetandcolddryroadsaswellasroadscoveredwithloosesnowchurnedupbyvehiclesfittedwithsnowchains.Thetreadreducessnowbuildupandmostdrivers’experienceanimprovedvehiclecontrolandhandlingduetotheaggressivetreadand softer rudder compound used to manufacture the winter tyre, wheel chains also work moreeffectivelywhenfittedtothewintertyres.

Howeverwhilesnowtyresareanexcellentoptionforwintersnowdrivingtheyshouldberemovedfromthevehicleattheendofeachwinterandreplacedwithsuitablesummertyres.Ifstoredcorrectlytheycanbe refitted to the vehicle at the start of the followingwinter and themotorist shouldbe able toachieveagoodfewwinterseasonsfromasetofgoodqualitywintertyres.



Inoverseascountriesthe introductionofa legalmarkingrelatedtotheperformanceof thesnowtyre

has made the identification of winter tyres simpler. The "Alpine" symbol, or the three-peak-mountainwithsnowflake(‘3PMSF’)cameintoforceinNovember2012underEURegulation661/2009on the Safety ofMotor Vehicles. The 3PMSF can only be used if a tyre passes aminimum requiredperformanceonsnow-thesocalled“snowgripindex”.

“MudandSnow”(eithermarkedasM+S,M.SorM&S)hasbeenusedtoindicatewintertyresformanyyears.AlthoughM+Shasalegaldefinition,itisnotrelatedtominimumperformancerequirementsbuthas been widely used by tyremanufacturers to indicate winter products. M+S remains a permittedmarkingbutwhileM+Styrehavebettersnowtractionthanregulartires, theydonotnecessarilypassthelegalsnowgripthreshold.TruewintertyrescarrybothM+Sand 3PSMFmarkings.

StuddedWinterTyres

Whilethewintertyreprovidesexcellenthandlingandcontrolofthevehiclecomparedtoothertypesoftyresusedonwinterroads,thestuddedtyreprovidesimprovedvehiclecontrol,brakingandhandlinginicyconditions.

Thestuddedwintertyreisdesignedtoprovideimprovedtractiononhardcompactedorglazedicyroadsbythestudspenetratingintothehardicewhilethetyreitsselfprovidestractionfromthelooseiceandsnowon the surface of the road. Contrary to popular belief the studs do not resemble spikes or thestudsfoundonadogcollarbutaresmalllittlemetalprotrusionsthatprotrudeoutwardsfromthetyresurface. The stud housing is imbedded in the tyre and the stud protrudes out of the housingapproximatelythethicknessofafivecentcoin.Thisenablesthetyretreadtoprovidemaximumtractionwithloosesnowandiceonthesurfaceoftheroadwhilethestudspenetrateintoanyhardcompactediceontheroadsurfacetogreaterimprovethetyre’stractioncapability.

Another characteristic of the studded winter tyre is the minimal stud length, the tyre’s rubbercompoundand treaddesign.Whenblack ice isexperienced the studspenetrates the thin layerof icejustenoughtoprovidetractionwhileallowingthetyretreadtomaintaincontactwiththesurfaceoftheroadallowingthetyretoprovidemaximumtractionwiththeroadwithoutanyexcessivewheelspinningthatcancausedetrimentaldamagetotheroadsurface.



Wheelchainswhenfittedinablackicesituationpreventthetreadofthetyremakingadequatecontactwiththeroadsurfacethusthevehicleisrelyingjustonthesteelchaintoprovidetractionforthevehicleandthiscontributestowheelspinandslippage.

Thephotoontheleftisofawinterstuddedtyreafteritssecondseasonofoperationandthephotoontherightisofanactualstud.Thesectionofthestudabovetheyellowlineiswhatprotrudesfromthetyresurfacetomakecontactwiththesurfaceoftheroad.Thesectionofthestudbelowtheyellowlineisimbeddedintothetyre.



WinterRoadTrial

TheRoad

The sectionof road the trialwas conductedon is fully sealed and traverses throughMtHothamandDinnerPlain,itrisestoanaltitudeof1,845metresandissubjectedtoconsiderablesnowfalls,blizzardsandhighwinds.TheGreatAlpineroadisalsoregularlysubjectedtotheformationofBlackIceduetothesnowmeltingandleavingathinlayerofwaterontheroadsurfaceandthenre-freezing.Theroadhasnumeroussharpcornersandsteephillsthatcanbecoveredwithdifferenttypesofsnowandiceatanytimeofthedayandnight.ExtremeweatherconditionsandvisibilityissuescansometimesresultintheroadbeingclosedbetweenHarrietvilleandOmeoforsafetyreasons.Thesurfaceoftheroadcandiffergreatlyandthismayincludevaryingdegreesoficeandsnowcover,slush,dry,frozenandwetandoftenallduringthesameday.

TheTrialVehicle

Asmentioned in the introduction of this report the vehicle used for testingwas a 2006 Toyota 4WDLandcruser6cyl4.2turbodieselsteeltrayutility.Theapproximateweightofthisvehicleis3000kgwithtools and equipment and the tyres fitted and tested in this report are Nokian Hakkapeliitta LT2(Studded).



TheTrial

Thestuddedwinter tyre trialhasbeenconductedonTheGreatAlpineRoadbetweenHarrietvilleandOmeoduringthewintersnowseasonsof2016and2017,overacombinedperiodof23weeks.Thetrialandassessmentshavebeenmadefromobservations,investigationsandexperimentationsandhasbeenconductedduringnormalroadpatroloperationalprocedures.

Duetotheweatherconditionsandtrafficflowitisimperativethatallroadpatrolissuesareconductedquickly, efficiently and safely, with minimal disruption to the public and other road users. The roadpatrolvehicleisrequiredtotravelquicklyandsafelytothesceneofvehicleincidentsandforthistobeachieveditisessentialthattheRoadPatrolvehiclehasthemaximumpossibletractionwiththesurfaceoftheroadatalltimes.

Please Note: It is assumed that all motorists will be driving to the requirements of the law or theconditions,whicheveristhesafer.Howevercertainparameters,withauthorisation,havebeenexceededwhensafe todoso for thebenefitof this trialandundernocircumstanceshouldanymemberof thepublicattemptanytypeofdrivingprocedureoutsidetherequirementsofthelaworconditions.Alsoforthe benefit of this trial is should be assumed that all roads are covered with snow and ice unlessmentionedtothecontrary.

FlatRoadTest

Drivingonflatsectionsofroadwithfreshsnowdepthsofapproximately25to100mmthevehiclefittedwith the previously mentioned winter tyres has a remarkable holding ability. The vehicle tracksextremelywell in a straight line and the rear of the vehicle hasminimal to no indication of slippagewhenpowerisappliedviatheacceleratorwhilstthevehicleisin2WDdrivemode.

Corneringtotheroadconditionsisaccomplishedwitheasewithnorearendslippageorlossofcontroldetected.Hard rapid accelerationwas applied andminimal rear end slippageoutwardswasdetectedwithoutanylossofcontrolofthevehicleandoncetheaccelerationwaseasedofftheslippageceased.

When the vehicle was placed in 4WDmode and the same test applied to the vehicle, it performedwithoutanyslippageatall.

In 2WDmodewhen travelling at 60 km/h, the brakewas applied at an even constant pressure; thevehicledrawstoastopwithoutanyslippage.

Travellinginthesamescenariobutthistimeapplyingthebrakehardandfastthevehiclebeginstoslidebutcomestoahaltrapidly.Atnotimedidthevehiclegainspeedbyslidingoniceorfeeloutofcontrolwhichisoftentheoutcomewithacomparablevehiclefittedwithhighwaytyresorwheelchainsiffittedtothefrontwheels.



Inthe4WDmodewhentravellingat60km/h,thebrakewasappliedatanevenconstantpressureandthevehicledrawstoastopwithoutanyslippage.

Travelling in4WDmodeandapplyingthebrakehardandfastthevehicledrawstoastopwithoutanyslippageatall. Infactwhenthevehiclespeedwasincreasedto75kmhinthissituationthevehiclestillfailedtoslide.Howeverinablackicesituationwithnosnowontheroadsurfaceatall,thevehicledidexperience a small amount of slippage of approximately less than 1.0meter but at no time did thevehiclefeeloutofcontrol.

During this trial numerous skid tests were conducted on varying road surfaces under varying snowconditionsincludingsmoothglazediceandblackicesituations.Askidtestisconductedbytravellingatnear the legal speed limit and applying the foot brake rapidly when safe to do so to encourage thevehicletoslide.AskidisnormallyachievedquiteeffortlesslybutusingtheNokianWinterStudTyresitwasquitedifficulttoachieveanyformofslideorskid.ThisisasimilarresultachievedwhentheNokianHakkapeliittaLT2Non-Studtyrewastestedduring2015undersimilarconditions.

UpHillTest

Theuphill testwas conductedon varying road surfaces due to thedifferent types of road conditionsexperiencedit includedblack ice,smooththick ice,freshsnowanddeepsnowchurnedupbyvehiclesfittedwithwheelchains.

Drivinguphillin2WDmodewasexceedinglyimprovedcomparedtostandardhighwaytyresandamarkimprovementoverstandardAllTerraintyres.

Whenaccelerationwasappliedtherearwheelsexperiencednoexcessivewheelspinandtractionandcontrol was not lost to the point to cause a concern. When rapid acceleration was applied a smallamountofwheelspinwasdetectedbutceasedatsoonasaccelerationwaseasedoffandtractionwasregained.Thetestvehiclewasabletoconductthistestregularlywithlittlechangetotheoutcomeeachtime.

When the 4WDmodewas engaged the vehicles steering wasmore responsive when driving aroundcornersandwhenaccelerationwasappliedaroundcornersthevehiclecontrolwasimproved.Thiswasduetothevehiclesfrontwheelspullingthevehiclewiththerearwheelpushingasopposeto justtherearwheelpushingthevehicle.Thisresultwasonlypossiblebecauseallwheelshadgoodequaltractionwiththeroadsurface.

Whentraversingaroundcornersiftherearofthevehiclehasgreatertractioninthissituationthanthefrontwheels,therearofthevehiclewilltrytoovertakethefrontofthevehiclebypushingthefrontofthevehicletotheside.Thesameoccursifthefrontwheelshavemoretractionthantherearwheelsofthe vehicle and the rear of the vehicle can slide out around the corner. This often happens ifwheelchainsarefittedandthedriverisalittleoverenthusiasticwiththeaccelerator.



It is imperative that vehicle momentum is maintained while driving uphill on snow or ice. If vehiclemomentumislostduetowheelspinoradriverfailstomaintainasuitableamountofaccelerationandtractionwiththeroadwhendrivinguphilland/oraroundcornersthevehiclewillslowdownandthiscanoftenresultwithavehiclestoppedontheroad,blockingtraffic.

Ithasbeenobservedovermanyseasonsthatvehicleswithhighwaytyresandfittedwithwheelchainswhentravellinginuphillsituationsexperienceexcessivewheelspinduetothelackoftractionandthisisexacerbatedbydriversapplyingexcessiveacceleration.

Itisoftenseenonuphill lanesoftheroadthatarecoveredwiththickicethathasbeenchurneduptotheconsistenceofbeachsandwhilethedownhillsideoftheroadremainscompactedascoveredearlierinthisreport.

Duringthe2017roadtestMtHothamenjoyedheavysnowfallsandthiscontributedtoagreatamountofsnowandicecoveringtheroad.Thewinterstudtyreshadnoissuewiththedeepchurnedupiceontheroad.Thewinterstud tyreshave theability to traveloversoft snowand iceandcompact it so toprovidetractionwithoutdiggingintothesnowandbecomingbogged.

Thetestvehicleconductedtestbytravellinguphillandcomingtoafullstoponicysectionsoftheroad.This testwasconductedonsectionsof the road inshadowsorshade, this isoftenwere the roadwillexperienceaslickertypeof icedependingonthetimeofdayduetothe lackofsun lightontheroadsurface.OntheGreatAlpineroadatMtHotham,CRBHillandDiamantinaCorneraretwooftheplacesutilisedforthisassessmentduetothesteepnessofthegradient.

Itmustbenotedthatavehicletravellinguphillatamoderatespeedcanmaintaintractionbutoncethevehicleisrequiredtostop,tractioncanbelostandthevehiclewillhavedifficultyregainingtractionandmoving off. This has been seen to happen to numerous vehicles includingmany newAWDand 4WDEuropeanvehiclesdesignedtooperateinthesnow.Inthissituationtheroadcanoftenbeblockedandothervehiclesarerequiredtostoponthesteepsectionofroadandthisleadstomorevehiclesloosingtractionandbecomingincapacitated.

Thetestvehiclehadlittleissueregainingtractionafterstoppingonuphillsectionsoftheroad.ThemanySipesandSipeActivatorsincorporatedintothesoftrubbercompoundofthetyrewiththeadditionofthestuds,noslippagewasexperienced.Thiswouldallowthe tyres togripandcompress thesmallestamountof snowon the surfaceof the road to regain traction to allow the vehicle tomoveoffwhenaccelerationwasappliedslowlyandgraduallyandoncemomentumwasachievedthevehicletravelledasnormal.

Inthesamesituationallterraintyresrequirealotmoresoftdrysnowtoregaintractionandthisisalsodependant on the amount of tread left on the tyre. This often requires the driver to roll the vehiclebackwardsintosoftdrysnowonthesideoftheroadandusethesameproceduretomoveoffslowly.However this is no guarantee that the vehiclewillmoveoff andwheel chainsmaybe required tobefitted.



AsforvehiclesfittedwithHighwaytyres,regardlessofwhattypeofvehicleitis(FourorAllWheelDrive)thisprocedurewillmostlikelyfailandwheelchainswillneedtobefittedtothedrivewheelstoassistthevehicletomoveoffandthisofteninvolvesalotofwheelspinningandthestrongpossibilityofthechainbreaking.

Howevertheonlytimeduringthetrial thatthetyreshaddifficulty ingainingtractionwasonasteep,sharpuphill cornerof the roadafter the testvehiclehadstoppedand thiswasdue to the roadbeingcoveredby smooth icewith theabsenceof any snow.Tractionwas soon regainedoncea fewshovelfull’sofsnowwereappliedtothesurfaceoftheiceandnormaltravelwassoonachieved.

Brakingonuphillsectionsoftheroadwasnotamajorissueassoonastheacceleratorwasreleasedthevehiclewouldsooncometoahaltwithoutanylossofcontrol.

DownHill

Travelling downhill and remaining in control of a vehicle on any typeof tyre in icy conditions canbedifficult.Asageneralruleregardlessofwhetherthevehicleisa4WDorAWD,thiswillnotassistinthebrakingprocessandmayworsenthesituationduetotheincreasedweightofthevehicle.Thisismoreorlesstrueinregardtothenewer4WDvehiclesthatemployanelectronicbreakingsystembuttheoldermechanicalsystemstillused intheToyotaLandCruiserandsomeothermodelsofvehiclesdobenefitfrombeinginthe4WDmodewhenbraking.Thiswasfoundtobetheoutcomeduringthetestingofthestuddedsnowtyres,usingaToyotaLandCruiserasthetestvehicle.



Whentravellingdownhillinastraightlinebrakingwasappliedbyapplyingpressuretothebrakepedalwiththefootjustlongenoughtoslowthevehicledownandthenreleased.Thiswasrepeateduntilthedesiredspeedwasachieved.

This method helps prevent the vehicle from sliding and if the vehicle does slide the foot brake isreleased,thewheelsbegintoturnandtheslidingstops.Thisisknownasfeatheringthebrake.

TheNokianHakkapeliittaLT2(Studded)tyrehandledthissituationwithease;thetestvehicleremainedin the tracking line of the frontwheels at all timeswith no indication of slippage. Slippagewas onlyachievedfortestingpurposeswhenspeedwasincreasedandtheclutchpedalandbrakepedalappliedabruptly.Oncethebrakeandclutchwasreleasedslippagestoppedandthefrontwheelbegunturning.

When negotiating a corner the on/off brakingmethod or featheringwas applied before entering thecornertoslowthevehicledowntothedesiredspeed.Onceinthecornerthevehiclecontinuedtotrackperfectly and the feathering brakingmethodwas employedwhile turning and no controlwas lost atanytimeorslippagedetected.

A simular testwas performed on the same corner 10minutes later at an increased speed and usingabruptbrakingmethods.Thevehicleslidinastraightlinebutassoonasthebrakewasreleasedtheslidestopped.Whentravellingaroundthecornertherearofthevehicleslidoutslightlybutregainedtractionassoonasthebrakewasreleased.

Itshouldbenotedthat inthissituationbrakingshouldbeappliedslowlyandcarefullytohelppreventsliding.Howeveritwasnotedthatthesmallestamountofsnowonanicecoveredroadgreatlyassistedwith traction but this can be dependent on several factors, the type of ice under the snow, thesteepnessoftheroadandtheweightandspeedofthevehicle.

Manyvehicleaccidentsonsnowandicecoveredroadsareduetovehiclesnotbeingabletostopwhenrequiredandthisisparticularlytrueondownhillsectionsoftheroad.



SummingUp

After extensive testing and experimentation of the Nokian Hakkapeliitta LT2 (Studded) tyre, it hasproventobearemarkabletyre.IthasallthepositivecharacteristicoftheNokianHakkapeliittaLT2Non-Studdedtyrebutwiththeaddedabilitytoprovidethatextratractionwhenneededonhardsmoothicyroadsurfacesincludingblackicesituations.Thetyresareabletoprovidetractionacrosssoftsnowwithoutspinningthewheelsthusgettingbogged.They provide the motorist with the reassurance to drive comfortably and consistently in a relaxedmanner,whilehandlethevaryingroadconditionsexperiencedontheGreatAlpineRoadduringwinterwhilstallowingthevehicletooperateasthemanufacturehadintended.The2017snowseasonprovidedMtHothamwithaperiodofintensesnowfallsnotseenformanyyearsandduringthisperiodtheroadwasclosedtothegeneralpublicfortwodaysduetotheheavyvolumeof snow on the road. This provided a unique opportunity to test the winter tyres beyond therequirementsofnormaldriving. This involveddriving throughandoverdeep snowat various speeds,stopping andmoving off on steep sections of the road and towing the odd stranded vehicle off thecarriageway.Thiswasallconductedwithoutanyissuesorproblemsandnotoncedidthetyresfailtoprovidethenecessarytractiontoaccomplishanoperation.Inthepastsimilarheavysnowsituationswouldrequirethefittingofwheelchainsandthiswouldgreatlyreducethecapabilitiesofthevehicleduetowheelspinningandtheincreasedlikelihoodofthechainedwheelsdiggingintothedeepsnowandthevehiclebecomingboggedandtheninmanycasesrequiringassistance.

Earlier in this report Imadereferenceto thewaywheelchainswork likeaBulldozercleatondirtbutunlikeaBulldozertrackwithcleatsthatspreadstheweightofthemachineoveralargearea,avehiclefittedwithwheelchainswillnoteasilytravelacrossdeepsnowwithoutspinningawheel.Awheelofaroadvehicleconcentratestheweightofthevehicledirectlyatthebottomofthetyre,approximatelythesizeofaCDcover. If thetyreoffers little tonotractionthewheelwill spinandthevehiclewill fail totravel.Ifwheelchainsarefittedtoatyrethatlackstheappropriatetractionthewheelchainswilldigthewheelintothesnowasthewheelspins.

Foravehiclefittedwithwheelchainstoworkattheoptimum,thevehicleneedstobetravellingonahard compacted surface that can provide enough penetration of the chain links and also enoughstrengthtoallowforthechaintogainresistancefromthecompactedsurfacetoallowthetorqueofthevehicletorotatethewheelwithoutspinning.Thesameapplieswhenbrakingand if thesurface is toothinorsoftforthechainstogainanyresistancethevehiclewillslide.

Thereareother factorsthatmustalsobeconsideredandtheyaretheweightof thevehicle, thetypeandconditionoftyresfittedtothevehicle,thegradientoftheroad,driverexpertiseandtosomepointthedrivesystemutilizedinthevehicle.



Up until 2014 the Road Patrol vehicle was fittedwith Bridgestone Dueller All Terrain tyres and theyservicedthevehicleverywellforthewholeyear.Duringthewintermonthstheyperformedequallywellbutitwouldbenecessarytofitwheelchainsonaregularbasisduetothevaryingroadconditions.

Howeverindoingsothevehicle’shandlingabilitychangeddramaticallyrequiringconstantreadjustmentofdrivingskillstomaintainsafeuninterruptedtravel.Thechainsalsohadadispositiontocontributetodamagingthevehicleandtheroadpavementifexcessivewheelspinoccurredorcontributedtofurtherdamageiftheroadpavementhadalreadybeencompromised.

Conclusion

After extensive experimentation, testing and assessments and considering the safety factor, vehiclehandling, driver experience or inexperience, vehiclemanufacture’s expectations and the varying roadconditions, thecertifiedwinter tyreand the studdedwinter tyreareamajor improvement forwinterconditionsoveranyother tyre seen inAustralia todate.While the fittingofwheel chains tohighwaytyres improves the traction capabilities of the vehicle, it is an inferior and sometimes problematicsolution togain tractioncompared to theuseofgoodquality certifiedwinter tyres.This isnot to saythat wheel chains are obsolete, they are an inexpensive method of gaining traction for the generalmotorist and have serviced many motorist in this country extremely well for many years and willcontinue todo so in to the future.Butover recent yearsoverseasTyreManufactureshave improvedtyre design way beyond the capabilities of the wheel chain. This is due to factors like; vehiclemanufacturesrequirements,newrubbercompoundsbeingproduced,driverconvenienceandsafety.

This is not to say thatwheel chainswill never be required to be fitted towinter tyres.Wheel chainsshouldstillbecarriedbutwouldnotneedtobefittedasoftenduetowintertyresbeingabletoprovideincreased traction over the use of wheel chains in amultitude of road conditions. But in certain icysituationswheelchainswould improve tractionwith the roadsurfaceandwhen fitted towinter tyreswillperformastheyareintendedto.

Afterallthathasbeencoveredinthisreportandduetothemanyvaryingfactorsinvolvedtherearefewhardandfastrulesthatcanbeadheredto.Buttheonerulethatisalwayspresentisthelawofphysics,thelackoftractionwiththeroadresultsinseriousissuesontheroad……andsometimesofftheroad.

TheStuddedTyreswouldnotbesuitableforvehiclestravellingtoandfromthesnowfieldsonnonsnowcovered roads but would be of a major advantage to vehicles that travel on snow covered roads amajorityofthetimethiswouldmostlikelybemountainstaffvehiclesorpeoplelivingabovethesnowlineduringwinter.Thenon-studdedwintertyreismorethancapabletotravelonsnowandnonsnowcoveredroadsbutshouldberemovedfromthevehicleattheendofeachwinterseasonandstoredforthefollowingseason.



It iswith absolute conviction that I strongly believewithout equivocation, that good quality certifiedwinter tyres, studded and non-studded are a superior method of gaining traction on snow and icecoveredroadsforpassengervehicles.

I would also like to advocate for consideration by Authorities for the introduction of certifiedwintertyresasasuperioralternativetowheelchains(asisthecustominoverseascountries)formotoristwhowish to utilise themhere inAustralia. Thiswould not be a practical option formost travellers to thesnowbutfortheregulartravellersandmountainresidentswhoarewillingtoinvestinwintertyresthiswouldbeanadvantage.

Butwhilethiswouldhelpimproveroadsafetyitwouldneedtobecloselymonitoredpossiblywiththeintroductionofa self fundedpermit system.Thepermit systemwouldhelpkeepunacceptable cheapqualityuncertifiedwintertyresofftheroadunlikethepresentsystemduetothelackofanAustralianstandard the market place has been inundated with substandard inappropriate cheap quality wheelchains.

Certainrequirementsandsafeguardswouldneedtobeimplementedforawintertyrepermitsystemtoworkreliablyandflawlessly,recommendationsareavailableonrequest.

ThisreporthasbeencompiledandwrittenbyGlennBillmanMtHothamRoadPatrol.

Thisconcludesthe2017WinterStudTyreReport.

Kindregardstoall.

GlennBillman.

winter stud tyre - snowtyres.com.au · while practical terminology will be used throughout the...

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