Shimano RD-M780-S GS, RD-M780-S SGS, RD-M780-L GS, RD-M780-L SGS Technical Service Instructions

SGS

10

43T

11T

18T

3. Chain length on bicycles with rear suspension

The length of A will vary depending on the movement of the rear
suspension. Because of this, an excessive load may be placed
on the drive system if the chain length is too short. Set the
length of the chain by adding two links to the chain when the rear
suspension is at a position where dimension "A" is longest and
the chain is on the largest sprocket and the largest chainring. If
the amount of movement of the rear suspension is large, the
slack in the chain may not be taken up properly when the chain is
on the smallest chainring and smallest sprocket.

4. Outer casing length

(1) Loosen the B-tension adjustment screw until it is in the

position shown in the illustration.

(2) Check that there is enough slack in the outer casing. Next,

align the outer casing with the bottom edge of the outer
casing holder at the rear derailleur and
then cut of any excess length of outer
casing.

Connect the cable to the rear
derailleur and, after taking up
the initial slack in the cable,
re-secure to the rear
derailleur as shown in the
illustration.

Add 2 links (with the chain on both the largest
sprocket and the largest chainring)

Largest
sprocket

Chain

Largest

chainring

Series

Shifting lever

Outer casing

Rear derailleur

Type

Freehub

Gears

Cassette sprocket

Chain

Bottom bracket guide

In order to realize the best performance, we recommend that the following combination be used.

Specifications

Model number

Type

Gears

Total capacity

Applicable sprocket combination

Smallest sprocket

Front chainwheel tooth difference

Rear Derailleur

General Safety Information

WARNING

“Maintenance interval depends on the usage and riding circumstances.
Clean regularly the chain with an appropriate chaincleaner. Never use
alkali based or acid based solvents such as rust cleaners. If those solvent
be used chain might break and cause serious injury.”

•

In order to obtain good gear shifting performance, this chain has a forward side
and a reverse side, and the sides are marked so that the chain will face the
correct way when installed. The proper design performance will be obtained when
the chain is installed so that it faces the correct way. If it is installed so that it
faces the opposite way, the chain may come off and the bicycle may fall over and
serious injury may occur as a result.

• Use the reinforced connecting pin only for connecting the narrow type of chain.

• If connecting pins other than reinforced connecting pins are used, or if a reinforced connecting
pin or tool which is not
suitable for the type of
chain is used, sufficient
connection force may not
be obtained, which could
cause the chain to break
or fall off.

• Make sure that the
connecting pin is aligned with the outer link surface from the side that
the pin is inserted. It should feel smooth and flush when you run your
finger over it.The pin will protrude slightly on the backside after the
break off pin is removed.

• If it is necessary to adjust the length of the chain due to a change in the
number of sprocket teeth, make the cut at some other place than the
place where the chain has been joined using a reinforced connecting
pin. The chain will be damaged if it is cut at a place where it has been
joined with a reinforced connecting pin.

• Check that the tension of the chain is correct and that the chain
is not damaged. If the tension is too weak or the chain is
damaged, the chain should be replaced. If this is not done, the
chain may break and cause serious injury.

• 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

• 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.

• You should periodically clean the derailleur and lubricate all moving parts (mechanism and
pulleys).

• If gear shifting adjustment cannot be carried out, check the degree of parallelism at the rear end
of the bicycle. Also check if the cable is lubricated and if the outer casing is too long or too short.

• If you hear abnormal noise as a result of looseness in a pulley, you should replace the pulley.

• You should periodically wash the sprockets in a neutral detergent and then lubricate them again.
In addition, cleaning the chain with neutral detergent and lubricating it can be a effective way of
extending the useful life of the sprockets and the chain.

• If the chain keeps coming off the sprockets during use, replace the sprockets and the chain.

• Use a frame with internal cable routing is strongly discouraged as it has tendencies to impair the
SIS shifting function due to its high cable resistance.

• Always be sure to use the sprocket set bearing the same group marks.
Never use in combination with a sprocket bearing a different group mark.

• Use an outer casing which still has some length to spare even when the
handlebars are turned all the way to both sides. Furthermore, check that the
shifting lever does not touch the bicycle frame when the handlebars are
turned all the way.

• A special grease is used for the gear shifting cable.Do not use DURA-ACE
grease or other types of grease, otherwise they may cause deterioration in
gear shifting performance.

• Grease the inner cable and the inside of the outer casing before use to ensure that they slide
properly.

• For smooth operation, use the specified outer casing and the bottom bracket cable guide.

• Operation of the levers related to gear shifting should be made only when the front chainwheel is
turning.

• The guide pulley has an arrow on it to indicate the direction of rotation.Install the guide pulley so
that the arrow is pointing counterclockwise when looking at the outer side of the derailleur.

• The tension pulley has an arrow on it to indicate the direction of rotation.Install the tension pulley
so that the arrow is pointing clockwise when looking at the outer side of the derailleur.

• 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.

g

a

-

18

T

-

S

H

I

M

A

N

O

H

Y

P

E

R

G

L

I

D

E

C

a

g

-

1

5

T

a

g

-

1

3

T

Group marks

Pull

Less than 30 mm

Tightening torque :

6 - 7 N·m {52 - 60 in. lbs.}

Groove

Note: Be sure that the cable is

securely in the groove.

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

* If the rear derailleur moves to a large degree, such as in

bicycles with rear suspension, it is recommended that you
replace the cap with an
aluminum cap.

The end of the outer casing
which has the aluminum cap
should be at the derailleur side.

Aluminum cap

Derailleur side

The sealed cap with
tongue and the rubber
shield should be
installed to the outer
casing stopper of the
frame.

Rubber shield

Rubber shield

Be careful not to bend

Sealed cap with tongue

5. How to use the B-tension adjustment screw

Mount the chain on the smallest chainring and the largest
sprocket, and turn the crank arm to shift gears.Then tur n the B­tension adjustment screw
to adjust so that the guide
pulley does not interfere
with the sprocket but not so
close that it touches the
chain. Next, set the chain
to the smallest sprocket
and repeat the above to
make sure that the pulley
does not touch the
sprocket.

<Checking the distance between the largest sprocket
and the guide pulley>

Set the rear derailleur to the lowest gear
position, stop the wheel from turning, and then
check that the distance from the edge of the
guide pulley to the edge of the largest sprocket
is within the range of 5 - 6 mm.Turn the crank
arm to shift gears and check that there is no
roughness in the feel. If the number of teeth for the cassette
sprocket is changed, carry out this setting again.

Largest sprocket Smallest sprocket

B-tension

adjustment screw

6. SIS Adjustment

Operate the shifting lever several times to move the chain to the
2nd sprocket.Then, while pressing the lever just enough to take
up the play in the lever, turn the crank arm.

When shifting to
3rd

Tighten the outer casing
adjustment barrel until the
chain returns to the 2nd
sprocket. (clockwise)

Loosen the outer casing
adjustment barrel until the
chain touches the 3rd sprocket
and makes noise. (counter
clockwise)

When no sound
at all is heard

Best setting

The best setting is when the shifting lever is
operated just enough to take up the play and the
chain touches the 3rd sprocket and makes noise.

* Return the lever to its original position (the position where

the lever is at the 2nd sprocket setting and it has been
released) and then turn the crank arm clockwise. If the
chain is touching the 3rd sprocket and making noise, turn the outer
casing adjustment barrel clockwise slightly to tighten it until the noise
stops and the chain runs smoothly.

Operate lever to change gears, and check that no noise occurs
in any of the gear positions.

For the best SIS performance, periodically lubricate all
power-transmission parts.

Adjustment barrel Adjustment barrel

Note:

The distance between the outer stopper to the outer casing
holder of the rear derailleur may change when the rear
suspension moves, so determine the length of the outer casing at
the point where this length is at its greatest.

Note:

Set the inner cable so that it protrudes by a
length of less than about 30 mm, and then
check that the inner cable does not interfere with
the spokes of the wheel. Stop the wheel from
turning while carrying out this step.

* Service Instructions in further languages are available at :

http://techdocs.shimano.com

Please note:specifications are subject to change for improvement without notice. (English)
© Jan.2011 by Shimano Inc. XBC SZK Printed in Japan.

One Holland, Irvine, California 92618, U.S.A. Phone: [phone]

Industrieweg 24, 8071 CT Nunspeet, The Netherlands Phone: [phone] Oimatsu-cho, Sakai-ku, Sakai-shi, Osaka 590-8577, Japan

This service instruction explains how to use and maintain the Shimano bicycle parts which have been
used on your new bicycle. For any questions regarding your bicycle or other matters which are not
related to Shimano parts, please contact the place of purchase or the bicycle manufacturer.

Outer casing

(1) (2)

SI-5XP0A-001-00

SI-5XP0A-001 Technical Service Instructions

RD-M780

Rear derailleur

Reinforced Connecting Pin

Link Pin Link Pin

Link surface

Connecting pin

Chain toolChain

10-speed super narrow

chain for MTB

Reinforced

connecting pin

TL-CN32
TL-CN23
TL-CN27

with groove (3)

with groove (2)

XT

SL-M780 / SL-M780-I

OT-SP41

RD-M780

SGS / GS

FH-M785 / FH-M788

10

CS-M771-10

CN-HG94

SM-SP17 / BT17

RD-M780

GS

10

35T

11T

18T

11 - 32T, 11 - 34T, 11 - 36T

Outer casing holder

Note: Periodically check that there is no gap between the
dropout and the bracket as shown in the illustration.If there is a
gap between these two parts, problems with gear shifting
performance may occur.

Installation of the rear derailleur

5 mm Allen key

Dropout

Bracket

Bracket spindle

Tightening torque :

8 - 10 N·m {70 - 86 in. lbs.}

1. Top adjustment

Turn the top adjustment screw to adjust so that the guide
pulley is in line with the outer line of the smallest sprocket
when looking from the rear.

2. Low adjustment

Turn the low adjustment screw so that the guide pulley
moves to a position directly in line with the largest sprocket.

SIS Adjustment

Top adjustment

screw

Low adjustment

screw

Guide pulley

Largest sprocket

Outer line of
smallest sprocket

Installation of the sprockets

For each sprocket, the
surface that has the group
mark should face outward
and be positioned so that
the wider part of each
sprocket and the A part
(where the groove width is
wide) of the freewheel body
are aligned.

The groove is
wide at one
place only.

a

c

-

1

4

T

A

Wide part

For installation of the HG sprockets, use
the special tool (TL-LR15/LR10) to tighten
the lock ring.

To replace the HG sprockets, use the
special tool (TL-LR15/LR10) and TL-SR21
to remove the lock ring.

Tightening torque:

30 - 50 N·m {261 - 434 in. lbs.}

Lock ring

Tool
(TL-SR21)

Disassembly

TL-LR15/LR10

< CS-M771-10 >

(bL) 11 - 32T
(bJ) 11 - 34T
(bk) 11 - 36T

Lock ring

Sprocket spacer

Lock ring spacer

■ Replacing the rear derailleur

Guide pulley / Tension pulley

Tightening torque :

2.5 - 5.0 N·m {22 - 44 in. lbs.}

3 mm Allen key

DEORE XT Rear Derailleur

RD-M780-S

(GS/SGS)

Silver Version (Long Cage/Super Long Cage)

RD-M780-L

(GS/SGS)

Black Version (Long Cage/Super Long Cage)

ITEM

NO.

1 Y5XP98010 B-Axle Assembly B
2 Y5XP98020 Bracket Axle Unit
3 Y5XP98030 B-Tension Adjusting Screw (M4 x 18) & Plate
4 Y5W798030 Cable Fixing Bolt (M5 x 8) & Plate A
5 Y5W798020 Stroke Adjusting Screws & Plate B A
6 Y5UC14000 P-Seal Ring AA
7 Y5W722000 P-Tension Spring A

Y5XP98040 Outer Plate Assembly (GS-Type)
Y5XP98050 Outer Plate Assembly (SGS-Type) B

9 Y5XF98060 Guide & Tension Pulley Unit B A

Y5XC09100 Inner Plate (GS-Type) B
Y5XF10100 Inner Plate (SGS-Type) A

11 Y53M24400 Pulley Bolt (M5 x13.95) B A

A: Same parts. Mar.-2011-3180
B: Parts are usable, but differ in materirals, appearance, finish, size, etc.

©

Shimano Inc.

A

Absence of mark indicates non-interchangeability.

Specifications are subject to change without notice.

8

10

INTERCHANGEABILITY

SHIMANO

CODE NO.

DESCRIPTION

R

D

-

M

9

8

0

R

D

-

M

6

6

3