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Page 1: The Importance of Using an Endurance Machine€¦ · CeramicSpeed has carried out an endurance test to illustrate the difference between a correct and incorrect test protocol. A single

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TheImportanceofUsinganEnduranceMachineinconjunctionwiththeChainEfficiencyTesterforEnduranceTesting.

AddressingMuc-Off’sclaimthattheUFOChainincreasesto14wattsduringaride.

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Muc-Offrecentlyreleasedabrochurewhichincludeddataregardingthelong-termperformanceoftheUFOChains.

ThisdocumentaddressesthemisleadingnatureofMuc-Off’sdata.BasedonwhatweknowofMuc-Off’stestingprocedure,weassumethismisleadingdataiscausedbyincorrectmethodsofacquiring‘endurancetest’data.Wedescribethecorrecttestmethods,andshowtheresultsofacorrecttestaswelltheresultsofatestrecreatingthemisleadingdata.

Inthefollowingparagraph,wewilldiscusshowandwhyusingthewrongtestmachinescanprovidemisleadingdata.ThisisfollowedbyathoroughdiscussionofhowweassumeMuc-Offhasperformedtheirtestingwhichissupportedbyareplicationoftheirassumedtestingmethodcomparedtothecorrectmethod.Astheresultswillshow,thetwodifferentwaysofperformingthetesting,leadstotwoverydifferentdataresults.

1.1HowcanmisleadingdatabecreatedfromanEnduranceTest?

BasedonthetestresultsMuc-Offpresented,wemustassumethattheyperformedthe‘endurancetests’withtheirtesterin“FullTension”mode.Whilethismodeprovidesthemostprecisemeasurementoffrictioninachain,itisdesignedtobeusedonlyforshort-termfrictionmeasurements.The“FullTension”modeshouldneverbeusedforlong-termendurancetesting.Forlongtermtesting,anEnduranceMachineshouldbeusedtomoreaccuratelysimulateanactualbikedrivetrain.Alternatively,forthepurest‘endurancetest’possible,thechainshouldberiddenonanactualbikeforseveralhourswithpre-rideandpost-ridefrictionmeasurementstakenusingtheFullTensionTester.

InthefollowingwewilldiscusshowaFullTensionTesterusedforlong-termtestingwillcausemisleadingdata.

1.2 WhyshouldtheFullTensionTesternotbeusedforlong-termtesting?

Whenattemptingtoaccuratelydeterminethe“Frictionvs.Time”graphforendurancetestingpurposes,boththeFullTensionTesterandanEnduranceMachinemustbeused.TheFullTensionTesterisusedsolelyforobtainingfrictionmeasurementsandtheEnduranceMachineisusedforsubjectingthechaintolong-termruntimesunderload.

TheFullTensionTestermeasureschainfrictionbyapplyinghighlevelsoftensionsymmetricallyontwochainspans.RearderailleurchainspansarenotpresentonaFullTensionTester.Granted,thistypeoftesterproducesthemostprecisechainfrictionmeasurementsofanytestmethod.Yettheconstant

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tensionloadingconditionsdonotmimicatruebicycledrivetrain,andinaccurateresultsforlong-termchainendurancemeasurementscanoccur.

Simplyput,theFullTensionTesterwasdesignedforshort-term,high-precisionfrictionmeasurements.Toperformproperendurancetestingofachain,thechainshouldbetestedonFullTensionTesterforaninitial

frictionmeasurement,thenswappedandlong-termtestedonarigthatissetuptorepresentabicycledrivetrain,withtruedrivepoweratthering,loadonthecog,andarearderailleursetup,suchasanEnduranceMachine,orevenanactualbicycle.Afterthechainisrununderloadforagivenamountoftime,thechainshouldbetransferredbacktotheFullTensionTestertogetasubsequentfrictionmeasurement.

Itisirrelevanttotestwhetherachainremainsfast(retainslowfriction)forlongperiodsoftimeontheFullTensionTester,asnobikechainiseveratsymmetricalfulltensionforseveralhours.Putdifferently,theFullTensionTesterdoesnotreflectareal-usescenario.

FulldescriptionsofthetwotypesofequipmentcanbefoundontheFrictionFactssite.

http://www.friction-facts.com/equipment/full-tension-test-method

http://www.friction-facts.com/equipment/chain-full-load

1.3The‘SlackingEffect’

TheissueswithusingtheFullTensionTesterforlongtermtestingarisefromthefactthatthechainisalwaysunderheavytension,onbothupperandlowerspans,andthechainisneverallowedtoslack.Inatruebicycledrivetrain,thechainslacksasitsnakesthroughtherearderailleur.Whenthechainslacks,thelubricants(solidsorliquids),onamicroscopiclevel,areredistributed,andthecontactlinesoftheslidingsurfacesareconstantlyshifting,continuouslycreatingnewcontactlinesoflubricant.Thisslackingrefreshesthechainandallowsthelubricanttoperformforlongdurations.

This‘slackingeffect’wasdiscoveredin2015byFrictionFacts.ItwasrecognizedthatduringlongertestingperiodsontheFullTensionTester,somelubricantswouldshowabnormalincreasesinfriction.DuringtestingofachainexperiencingthisabnormalincreaseinfrictionontheFullTensionTester,thechainfrictionwouldinstantlydropbackdowntoanormallevel,yetslowlycreepupagainovertime,iftheloadwasremovedforafewseconds,withtheequipmentstillturning(ie,thechainwasslacked),andtheloadthenre-applied.Thisphenomenoncouldeasilyberepeatedmanytimesduringasinglelong-termtestrun,quicklyliftingandre-applyingtheloadtoslackthechainandthefrictionlevelswouldreturntonormal.

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Thisbehaviourofrisingfrictionlevelsoverlongerperiodsduetoafully-tensedchainisobviouslynotconducivetoaccuratelong-termtesting.ToconfirmtheFullTensionTesterwasnotsuitableforlongtermmeasurementsbasedonthetheorythattheFullTensionTesterdidnotallowslacking,endurancetestingwasperformedonmultiplechainsamplestoexposethedifferencesbetweenusingonlytheFullTensionTesterversustheFullTension/EnduranceMachinecombination.TheFullTension/EnduranceMachinecombinationproducedtherepeatableandrealisticresultsexpectedinthistypeofalong-termtestsituation.

Afterconfirmationtestingprovedthistheory,thefindingsledtotheprotocolofusing1)afull-fledgedreplicaofabicycledrivetrainforlongevityloading(theEnduranceMachine),and2)usingtheFullTensionTesteratpre-describedintervalsforobtainingprecisionfrictionmeasurements.Undoubtedly,thefindingsprovedtheFullTensionTestercannotbeusedaloneforlongtermendurancetests.

Becauseofthisdiscovery,FrictionFactsdevelopedanewEnduranceTestprotocol,whichincorporatedtheuseofanEnduranceMachineinconjunctionwiththeFullTensionTesterforaccurate,fair,andrepeatable“frictionvs.time”endurancetesting.Inthefollowingparagraphs,wewilldiscusswhyitappearsthatMuc-Offarebasingtheirtestresultsonincorrecttestingmethodsandasaconsequenceofthat,haspublishedmisleadingdata.Thediscussionisbasedonassumptionssincewewerenotpresentduringthetesting,buttheseassumptionsissupportedbyathoroughreplicationoftheassumedtestingmethodcomparedtothecorrecttestingmethodsasbeingdiscussedinthepreviousparagraphs.

TogetthefullunderstandingofhowandwhyweassumeMuc-Offhascomeupwiththisdata,pleasereadthebelowdiscussion.

2.1WhyisitassumedthatMuc-OffperformedtheendurancetestingwithonlytheFullTensionTester?

The‘slackingeffect’abnormalityiseasilydetectableonany“chainfrictionvs.time”graph.Theslackingeffectpresentsitselfasarelativelylargerate-of-increaseinfrictionovertime,withadrasticdecreaseinfrictionwhenthefulltensionisremovedandre-applied,followedbyasubsequentincreaseinfrictionsimilartotheinitialincreaseinfrictionbeforethechainwasslacked.

Forthisdocument,FrictionFactsperformedanendurancetestusingtheincorrecttestprocedures,effortlesslyrecreatingsimilar(andincorrect)datatothedatathatMuc-Offpublished.Atestusingthecorrectprocedureswasalsoperformed,highlightingtheproceduralerrors,andprovingtheUFOChainisa4-wattchain,nota14-wattchain.Thisreplicationofdatacanbeseeninalatersection.

Muc-Offoriginallyproducedthe“UFOchainfrictionvstime”graphwithtwodaysofdata,Day1andDay2,usingthesameUFOChainforbothdays(seeGraph1).NotehowtheUFOChain’sfrictionlevelsdroppedfrom14+wattsdownto6wattswhenthechainwasremovedfromtheFullTensionTesterafterDay1andre-testedforthesubsequentDay2testrun.

ThisdrasticdropintheUFOChainfrictionobviouslybegsthequestion;Howcouldachainget8wattsfasterbysittingovernight?Theanswerisitdidn’tget8wattsfaster.Thechainwasnevera“14-watt

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chain”tobeginwith,eventhoughtheFullTensionTesterwasputtingoutthisdata.TheFullTensionTesterwasproducingincorrectandexcessivelyhighfrictionreadingsduetothelongdurationtest.Thisisundoubtedlyduetothe‘slackingeffect”,andisatell-talesignthattheFullTensionTesterwasemployedincorrectlyforlongtermtestinginthiscase.

Graph1:Muc-Off’soriginalgraphshowingaUFOChaindecreasing8wattsovernight,betweenDay1andDay2testing.

Muc-Off’soriginalgraphindicatessomethingispotentiallyflawedwiththetestduetotheinstantaneousdropinfrictiononthesameUFOChainbetweentestruns.WhentherecentNTCChainbrochurewaslaunched,the“Day2”datacontainingtheanomalywasremovedfromthegraph(seeGraph2).

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Graph2:The“revised”graphasseenintheNTCBrochure.TheDay2datawasdeletedforthepublicationoftheNTCbrochure.

CeramicSpeedhasnowayofknowingifMuc-Offisawareoftheconsequencesofthe‘slackingeffect’phenomenaorindeedwhythegraphwasrevised.

Regardlessofthat,an8-wattimmediatedecreaseinchainfrictionbetweentestruns,onthesamechain,shouldquicklyraiseeyebrowsinanysituation,andMuc-Offoughttohaverevisitedtheirtest.

2.2ReplicationofMuc-Off’sEnduranceTestandSubsequentDataCollected

CeramicSpeedhascarriedoutanendurancetesttoillustratethedifferencebetweenacorrectandincorrecttestprotocol.

AsingleCeramicSpeedUFORacingChain(KMCversionforthesakeoftesting)wasruncontinuouslyfora4-hourendurancetest.Thefirst3hoursofthetestwereperformedproperly.The4thhourwasperformedincorrectly.Thegraphbelowisanactual“printscreen”fromthetester.Ithasnotbeenalteredormanipulatedinanywayexceptfortheaddedtext.

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Forthefirstthreehours,thechainwasrununder250WloadontheEnduranceMachine.At15-minuteintervals,thechainwasremovedfromtheEnduranceMachine,placedontotheFullTensionTesterfora1-minutefrictionmeasurement,andthenplacedbackontheEnduranceMachine.Notethestable,realistic,andexpectedbehaviouroftheUFOChain.Thefrictionlevelsmaintainamid4-wattrangeforthefirstthreehoursofthetest.

Afterthe3-hourcorrecttest,theincorrecttestprocedurewasinitiated.ThechainwasremovedfromtheEnduranceMachineandplacedontheFullTensionTester.However,thechainwasallowedtoremainontheTensionTesterforonehour.NotetherelativelyfastincreaseinfrictionlevelswhenthechainisontheFullTensionTesterforthislongperiodoftime.Thissteadyincreaseinfrictionduringthe4thhourisverysimilartotheUFOChainfrictionincreaseseeninMuc-Off’sgraph.

Afteranhouroftheincorrectprocedure,thechainwasremovedfromtheFullTensionTesterandplacedbackontheEnduranceMachinefor10minutes,toallowthechaintoslackthroughtherearderailleurspans,andthenafinalfrictionreadingwastakenontheFullTensionTester.Thefinalfrictionreadingwas4.75W.

Thistestshowshowfrictionmeasurementscanincorrectlyclimbwhenachainisrunlong-termonaFullTensionTester,andhowthefrictionalmostimmediatelydropstooriginallevelswhenthechainistakenoffthetesterandallowedtoslack.ThedatafromthisincorrecttestissimilartoMuc-Off’soriginalgraph.ThechainfrictionincreasedsignificantlyduringDay1underFullTension,thensuddenlydroppedduetoslackingattheendofDay1,thenthefrictionincreasedagainduringDay2underFullTensionTester.

ThistestalsoprovesthataUFOChainmaintainssub5-wattfrictionlevelat250Wover4hours.

Asmentionedearlier,theFullTensionTesteristheonlyknownwaytomeasurechainfrictionprecisely,butmustbeusedforshortdurationstoobtainaccuratefrictionreadings.

BothCeramicSpeed’sFrictionFactslabintheUS,andtheirtestlabattheDenmarkheadquartershavematchingFullTensionTestersandEnduranceMachines.Anyandallendurancetestingisperformedwiththeproperprotocol,byusingthesetwomachinestogether.

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Severalmonthsago,CeramicSpeedtestedvariousfactory-treatedchainsforcomparisonpurposes.Thegraphbelowshowstheresultsaproperlyperformed,realisticendurancetest,usingthetwomachines.

Pleasenote,thattheMuc-OffNanotubeChainwasn’treleasedatthetimethistestingwasperformed.TheMuc-OffchaininthisgraphisthereforenottheNanotubeChainbuttheMuc-OffNTOCChain(NanotubeOptimisedChain).

CeramicSpeedhaspubliclypostedthe“EnduranceTestProtocol”forpurposesoftransparencyandintegrityintestmethodology.

Theprotocolcanbefoundonlinehttp://www.ceramicspeed.com/sport/techlab/tests/chain-efficiency-over-time/.


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