Designation:F1426−11StandardPracticeforIdentifyingTireTreadSurfaceIrregularWearPatternsResultingfromTireUse1ThisstandardisissuedunderthefixeddesignationF1426;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONOneofthemainperformancecharacteristicsoftiresisthetreadlife,definedasthenumberofkilometresormilestowear-out,orwheretheconditionofthetreadpatternrequirestheremovalofthetire.Beforereachingtheconditioncalled“wear-out,”intermediateconditionsoftreadweararefrequentlyencountered,bothintiretestingandinnormaltireuse,thatarecharacterizedbycomplextopologicaltreadpatternfeaturesusuallycalled“irregularwear.”Whenirregularwearispresent,certainothertireperformancefeatures,suchasnoiseandhandling,mayfallbelowacceptablenorms.Therefore,itisimportantintiredevelopmenttestingandtheassessmentoftireuseperformancetobeabletodescribeaccuratelytheconditionofthewornsurfaceoftires.Overtheyears,differentdescriptivenameshavebeengiventotheseworntreadpatternfeatures.Astandardizednomenclaturesystemisneededtobeabletoidentifythefeaturesthatarepresentanddescribetheintensityormagnitudeofthesefeatures.Thispracticeisintendedtogivesufficientinstructionstopermitanevaluationofirregularwear.Todescribeadequatelythefeaturesofthesetreadpatterns,itisnecessarytodevelopaspeciallogicalprogressivesequenceofdefinitionsordescriptions.1.Scope1.1Thispracticeprovidestheinstructionsandnomenclaturetoevaluatethewearfeaturesofthetreadpatternonatireforsomeintermediatestateshortoftotalwearout.1.2Atiremaybecharacterizedbycertainworntreadpatternconditionsthatarecollectivelyreferredtoas“irregularwear”features.Definitionsforthesefeaturesaregiveninaspeciallogicalandconceptualsequence.First,basictreadpatterndefinitionsaregiven.Then,additionaltreadpatterndefinitionsdirectlyrelatedtothebasictreadpatterndefini...
