Shimano FD-M781 Service Instructions

Brand: Shimano

Model: FD-M781

Type: Service Instructions

This manual is also suitable for

Shimano FD-M781-D is a triple front derailleur compatible with 42-32-24T chainrings, designed for precise and smooth shifting. It features an adjustable top and low adjustment screws for fine-tuning derailleur position and eliminating chain rub. The derailleur also includes a chain guide to prevent the chain from derailing and is compatible with various frame types, including normal and top-route installations. With its user-friendly design and reliable performance, the Shimano FD-M781-D is an excellent choice for mountain bikers seeking enhanced shifting capabilities.

General Safety Information

WARNING

•

Becarefulnottoletthecuffsofyourclothesgetcaughtinthechainwhileriding,otherwiseyoumayfalloffthe

bicycle.

•

Obtain and read the service instructions carefully prior to installing the parts.Loose,wornordamagedparts

maycausethebicycletofalloverandseriousinjurymayoccurasaresult.Westronglyrecommendonlyusing

genuineShimanoreplacementparts.

•

Obtain and read the service instructions carefully prior to installing the parts.Ifadjustmentsarenotcarriedout

correctly,thechainmaycomeoffandthismaycauseyoutofalloffthebicyclewhichcouldresultinserious

injury.

•

ReadtheseTechnicalServiceInstructionscarefully,andkeeptheminasafeplaceforlaterreference.

Note

•

Thisfrontderailleurisfortriplefrontchainwheeluseonly.Itcannotbeusedwiththedoublefrontchainwheel,

astheshiftingpointsdonotmatch.

•

Ifgearshiftingoperationsdonotfeelsmooth,washthederailleurandlubricateallmovingparts.

•

Iftheamountofloosenessinthelinksissogreatthatadjustmentisnotpossible,youshouldreplacethe

derailleur.

•

Whenthechainisinthepositionshownintheillustration,the

chainmaycontactthefrontchainringsorfrontderailleurand

generatenoise.Ifthenoiseisaproblem,shiftthechainontothe

next-largerrearsprocketortheoneafterifthechainisinthe

positionshowninFigure1.Shiftthechainontothenext-smaller

sprocketortheoneafterifitisinthepositionshowninFigure2.

Fig.1 Fig.2

Front

chainrings

Rear

sprockets

•

Forframeswithsuspension,thechainstayanglewillvarydependingonwhetherthebicycleisbeingriddenor

notbeingridden.Whenthebicycleisnotbeingriddenandthechainispositionedonthelargest/largerchainring

andonthesmallestsprocket,thechainguideouterplateofthefrontderailleurmaytouchthechain.

•

Shimanodoesnotprovidethebottombracketmountxingbolts.

•

Forsmoothoperation,usethespeciedoutercasingandthebottombracketcableguide.

•

Partsarenotguaranteedagainstnaturalwearordeteriorationresultingfromnormaluse.

•

FormaximumperformancewehighlyrecommendShimanolubricantsandmaintenanceproducts.

•

Foranyquestionsregardingmethodsofinstallation,adjustment,maintenanceoroperation,pleasecontacta

professionalbicycledealer.

•

BesuretoreadtheserviceinstructionsfortheFrontDriveSysteminconjunctionwiththeseserviceinstructions.

Technical Service Instructions SI-5N30A-001

FD-M780 / FD-M780-E

FD-M781 / FD-M781-D

Frontderailleur

Speciﬁcations

 X=Available

Modelnumber FD-M780 FD-M780-E FD-M781 FD-M781-D

Normaltype X

Toproutetype X

Frontchainwheeltoothdifference 18T

Min.differencebetweentopandintermediate 10T

Frontderailleurinstallationbanddiameter S,M,L – S,M,L –

Chainstayangle(α) 66°-69°

Applicablechainline 50mm

Applicablefrontchainwheel Fortriplechainwheelonly(42-32-24T)

Installation of the front derailleur

For bracket type

Installasshownintheillustration.

, Tightening torque :

35 - 50 N·m {305 - 435 in. lbs.}

Tightening torque :

5 - 7 N·m {44 - 60 in. lbs.}

FrontChainwheel

FrontDerailleur

Bolt

AdapterAdapter

Note:

Wheninstallingthecomponentstocarbonframe/handlebarsurfaces,verifywiththemanufacturerofthecarbon

frame/partsfortheirrecommendationontighteningtorqueinordertopreventovertighteningthatcancausedamage

tothecarbonmaterialand/orundertighteningthatcancauselackofxingstrengthforthecomponents.

Aftertakinguptheinitialslackinthecable,re-securetothefrontderailleur

asshownintheillustration.

< Normal type > < Top route type >

Pull

Top adjustment

Setsothattheclearancebetween

thechainguideouterplateand

thechainis0-0.5mm.

Smallest

sprocket

Largest

chainring

Chain position

Chainguide

outerplate

Chain

FD-M780

FD-M780-E

FD-M781

FD-M781-D

Topadjustment

screw

Adjustment of the intermediate

chainring

Whencarryingoutadjustment,setthechain

tothelargestsprocket,andatthefront,set

thechaintotheintermediatechainring.

Adjustusingtheoutercasingadjustment

barrelsothattheclearancebetweenthechain

guideinnerplateandthechainis0-0.5mm.

Chainguide

outerplate

Chain

Largest

sprocket

Intermediate

chainring

Chain position

Chainguideouterplate

Troubleshooting chart

Aftercompletionofsteps1-4,movetheshiftinglevertocheckthe

shifting.(Thisalsoappliesifshiftingbecomesdifcultduringuse.)

Ifthechainfallstothecrankside. Tightenthetopadjustmentscrew

clockwise(about1/4turn).

Ifshiftingisdifcultfromthe

intermediatechainringtothe

largestchainring.

Loosenthetopadjustmentscrew

counterclockwise

(about1/8turn).

Ifshiftingisdifcultfromthe

intermediatechainringtothe

smallestchainring.

Loosenthelowadjustmentscrew

counterclockwise

(about1/4turn).

Ifthechaindoesnotshift

smoothlyfromtheintermediate

chainringtothelargestchainring

eventhoughthetopadjustment

bolthasbeenadjusted.

Turntheoutercasingadjustment

barrelabout1/4ofaturn

counterclockwise.

Ifthechaindoesnotshift

smoothlyfromtheintermediate

chainringtothesmallestchainring

eventhoughthelowadjustment

bolthasbeenadjusted.

Turntheoutercasingadjustment

barrelabout1/4ofaturn

clockwise.

Ifthereisinterferencebetween

thechainandthefrontderailleur

innerplateatthelargest

chainring.

Tightenthetopadjustmentscrew

clockwise(about1/8turn).

Ifthereisinterferencebetween

thechainandthefrontderailleur

outerplateatthelargest

chainring.

Loosenthetopadjustmentscrew

counterclockwise

(about1/8turn).

Iftheintermediatechainringis

skippedwhenshiftingfromthe

largestchainring.

Loosentheoutercasing

adjustmentbarrel

counterclockwise(1or2turns).

Ifthereisinterferencebetween

thechainandfrontderailleur

innerplatewhentherearsprocket

isshiftedtothelargestsprocket

whenthechainwheelisatthe

intermediatechainringposition.

Tightentheoutercasing

adjustmentbarrelclockwise

(1or2turns).

Ifthechainfallstothebottom

bracketside.

Tightenthelowadjustmentscrew

clockwise(about1/2turn).

Iftheleverisstiffwhenshifting

fromtheintermediatechainringto

thelargestchainring.

Loosenthetopadjustmentscrew

counterclockwise(about1/4turn).

Installtheinnerholecoverbyturningitas

shownintheillustrationuntilitstops.

Donotturnitanyfurtherthanthis,

otherwiseitmaydamagethethreadonthe

cover.

Innerholecover

Cutting the outer casing

Whencuttingtheoutercasing,cutthe

oppositeendtotheendwiththemarking.

Aftercuttingtheoutercasing,maketheend

roundsothattheinsideoftheholehasa

uniformdiameter.

Attachthesameouterend

captothecutendofthe

outercasing.

Outerendcap



•

FD-M780 / FD-M780-E

FD-M780-E (Models without BB plate)

Usean8mmspannerora4mmAllenkeytotightenthewirexingbolt.

8mmspanner

< Normal type > < Top route type >

4mmAllenkey

Note:

Passthecablethroughasshown

intheillustration.

Wirexingbolt

•

FD-M781

< Normal type > < Top route type >

5mmAllenkey

Note:

Passthecablethroughasshown

intheillustration.

Wirexingbolt

•

FD-M781-D

< Normal type > < Top route type >

5mmAllenkey

Note:

Passthecablethroughasshown

intheillustration.

Wirexingbolt

Tightening torque :

6 - 7 N·m {52 - 60 in. lbs.}

SI-5N30A-001-00

•

FD-M780 / M781

Installthefrontderailleurasshownintheillustration.

Atthistime,adjustthepositionofthefrontderailleur

whileinstallingitsothatthereisaclearanceof1-3

mmbetweenthechainguideouterplateandthe

maximumouterdiameterofthelargerchainring.

Chainguideouterplate

Clearance:

1 - 3 mm

Pro-Setgauge

Maximumouterdiameter

Pro-Setalignment

block

Settheheightofthefrontderailleur.Theatsection

ofthechainguideouterplateshouldbedirectlyabove

andparalleltothelargestchainring.Secureusinga5

mmAllenkey.

Tightening torque :

5 - 7 N·m {44 - 60 in. lbs.}

Chainguide

Chainwheel(largestchainring)

•

FD-M781-D

Tightening torque :

5 - 7 N·m {44 - 60 in. lbs.}

155.5mm*

42T

159.5mm*

42T

155.5mm/159.5mm*

(Frombottombracket

center)

*

Theinstallationheightwillvarydependingonthe

positionoftheframewasher.

Models without BB plate

•

FD-M780-E

Bottombracketmountxingbolt

Note:Shimanodoesnotprovide

thebottombracketmount

xingbolts.

Bottombracket

mount

Bracket

Example:WhenusinganAllenkey

Tightening torque :

5 - 7 N·m {44 - 60 in. lbs.}

SIS Adjustment

Besuretofollowthesequencedescribedbelow.

*

Ifthebicyclehasrearsuspension,rstchecktherecommendedsegmentpositionaccordingtotheowner’smanualfor

thebicycle.Next,useaxingbandorsimilartosettherearsuspensiontotherecommendedstrokefortherear

suspension,andthenadjustthefrontderailleur.

Low adjustment

FirstremovethePro-Setalignmentblock.

Next,setsothattheclearancebetweenthechainguideinnerplateandthe

chainis0-0.5mm.

Chainguide

innerplate

Chain

FD-M781

FD-M781-D

FD-M780

FD-M780-E

Lowadjustment

screw

Pro-Setalignment

block

Largest

sprocket

Smallest

chainring

Chain position

Connecting and securing the inner cable

Switchthemodeconvertertothe3x(triplemode)position,andthencheck

thelowestposition.OperateleverBtwotimesormoretosettheleverto

thelowestposition.Removetheinnerholecover,andinstallthecable.

Mode converter

Modeselectswitch

Note:

Donotforcethemodeselectswitchtoturn.Ifyouforceittoturn,itwill

break.

Innercable

Lever(B)

Innerholecover

One Holland, Irvine, California 92618, U.S.A. Phone: +1-949-951-5003 Industrieweg 24, 8071 CT Nunspeet, The Netherlands Phone: +31-341-272222 3-77 Oimatsu-cho, Sakai-ku, Sakai-shi, Osaka 590-8577, Japan

*

ServiceInstructionsinfurtherlanguagesareavailableat:http://si.shimano.com

Pleasenote:specicationsaresubjecttochangeforimprovementwithoutnotice.(English)©Nov.2014byShimanoInc.HTR