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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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