Shimano RD-7800 - TECHNICAL,RD-7800 Service Instructions Manual

4. How to use the B-tension adjustment screw

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

1. Top adjustment

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

5. 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.

Technical Service Instructions SI-5V50D

Rear Derailleur

General Safety Information

WARNING

• Use neutral detergent to clean the chain. Do not use alkali-based or
acid based detergent such as rust cleaners as it may result in
damage and/or failure of the chain.

• 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.

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

• 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.

• 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.

• Be sure to check that the
connecting pin protrudes
uniformly from the link surfaces
at both ends after the chain has
been joined.

• 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 par ts may cause injury to the
rider. We strongly recommend only using genuine Shimano
replacement parts.

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

Note

• If gear shifting operations cannot be carried out smoothly, clean 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.

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

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

• 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.

• The tension pulley has a mark which indicates the direction of
rotation. The side with the arrow is the front side.

Chain toolChain

10-speed super narrow

chain such as

CN-7801 / 6600

Reinforced

connecting pin

TL-CN32 / TL-CN23

with groove (3)

1

1 2

2

Link Pin

Reinforced
Connecting Pin

Aluminum cap

Dropout tab

5 mm Allen key

B-tension adjustment screw

Smallest
sprocket

Largest
chainring

Chain

90°

Guide pulley

Tension pulley

Right angle to the ground

Derailleur side

4-mm cap

Plastic cap or 4-mm cap

Guide pulley

Outer line of
smallest sprocket

Top adjustment

screw

Link Pin

1

1 2

2

1

2

2

1

1 2

Largest sprocket

Guide pulley

Largest sprocket Smallest sprocket

Low adjustment

screw

B-tension

adjustment screw

2. Connection and securing of the cable

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.

Pull

Series

Type

Total capacity

Largest sprocket

Smallest sprocket

Front chainwheel
tooth difference

Double

Triple

Shifting lever

Gears

Outer casing

Rear derailleur

Type

Freehub

Cassette sprocket

Chain

Bottom bracket cable guide

DURA-ACE

ST-7801

ST-7803

10

SIS-SP41

RD-7800

SS / GS

FH-7800

CS-7800

CN-7801

SM-SP17

GS

37 teeth or less

27T

11T

22 teeth or less

SS

29 teeth or less

27T

11T

14 teeth or less

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

Specifications

Installation of the rear derailleur

Chain length

Stroke adjustment and cable securing

Bracket spindle

tightening torque:

8 - 10 N·m

{70 - 86 in. lbs.}

When installing, be careful that deformation is not caused by the
B-tension adjustment screw
coming into contact with
the dropout tab.

● In case of a triple
front chainwheel

RD-7800

Tightening torque:

5 - 7 N·m {44 - 60 in. lbs.}

Note:

Be sure that the
cable is securely in
the groove.

Groove

3. Low adjustment

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

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

Largest
sprocket

Largest
chainring

2

3

Chain

+2 links

Lever (A)

When shifting to 3rd

Tighten the outer cable
adjusting barrel until the
chain returns to the 2nd
sprocket. (clockwise)

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.

These service instructions are
printed on recycled paper.

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

Outer casing
adjustment barrel

Outer casing
adjustment barrel

Please note: specifications are subject to change for improvement without notice.
(English)
© Jan. 2005 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]

3-77 Oimatsu-cho, Sakai, Osaka 590-8577, Japan

Not OK OK

Play

If the smallest sprocket is
15T or 16T