Shimano SG-8R20, SG-8R25, CJ-8S20 Service Instructions Manual

SI-34R0B

SG-8R20
SG-8R25

CJ-8S20

Left

Fork end

Non-turn washer

Reversed

Standard

5R/ Yellow

6R/ Silver

5L /Brown

6L /White

Mark/ Color

Size

Right

7R/ Black 7L /Gray

Reversed

(full chain case)

5R/ Yellow

= 0

= 0

5L /Brown

7R

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

C

J-8S
2
0

J

AP
A
N

LOCK

6R

CJ-8S20

JAPAN

LOCK

C

J-8S
2
0

J

A

PAN

LOCK

7R

GREASE

7R

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

Right side of
the hub body

3.

1.

1.

2.

General Safety Information

WARNING

– To avoid serious injuries:

NOTE:

You can shift gears while pedaling, but on rare occasions
the pawls and ratchet inside the hub may produce some
noise afterwards as part of normal gear shifting operation.

The CJ-8S20 cassette joint should only be used with
sprockets from 16T to 23T.

If the wheel becomes stiff and difficult to turn, you should
lubricate it with grease.

Do not apply any grease to the inside of the hub,
otherwise the grease will come out again.

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.

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 handling or
adjustment, please contact the place of purchase.

When securing the brake arm to the frame, be sure to
securely tighten the clip screw and clip nut to the
specified tightening torque. Use lock nuts with nylon
inserts (self-locking nuts) for the clip nut. It is
recommended that standard Shimano parts be used for
the clip screw, clip nut and brake arm clip. If the clip nut
comes off the brake arm, or if the clip screw or brake arm
clip becomes damaged, the brake arm may rotate on the
chainstay and cause the handlebars to jerk suddenly, or
the bicycle wheel may lock and the bicycle may fall over,
causing serious injury.

When installing the hub to the frame, be sure to install
the correct non-turn washers to the left and right sides,
and securely tighten the hub nuts to the specified
torques. If the non-turn washers are installed to one side
only, or if the hub nuts are not tightened sufficiently, the
non-turn washer may fall out, which could cause the hub
axle to rotate and the cassette joint to turn. This may
then cause the handlebars to be accidentally pulled by
the shifting cable, and an extremely serious accident
could result.

Obtain and read the service instructions carefully prior to
installing the parts. Loose, worn, or damaged parts may
cause serious injury to the rider.
We strongly recommend only using genuine Shimano
replacement parts.

Check that the wheels are fastened securely before
riding the bicycle. If the wheels are loose in any way,
they may come off the bicycle and serious injury may
result.

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

Technical Service Instructions

Be sure to read these service instructions in conjunction
with the service instructions for the Inter-M Brake and the
Inter-8 shifting lever before use.

These service instructions explain 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.

Jul. 2003 by Shimano Inc. PIT. SZK. Printed in China

C

One Holland Irvine CA 92618 U.S.A. Phone [phone]

Industrieweg 24 NL-8071 CT Nunspeet‚ Holland Phone [phone]

3-77 Oimatsucho‚ Sakai‚ Osaka‚ Japan Phone [phone]

Please note: Specifications are subject to change for improvement without
notice. (English)

When installing the brake arm clip, securely
tighten the clip screw while holding the clip nut
with a 10 mm spanner.

Note:

After installing the brake arm clip, check that the
clip screw protrudes about 2 – 3 mm from the
surface of the clip nut.

Clip nut

Brake arm

Brake arm clip

Clip screw
(M6 16 mm)

Take up the slack in the chain and secure the wheel to
the frame with the cap nuts.

2 – 3 mm

Non-turn washer

Cap nut

4.

5.

Tightening torque:
2 – 3 Nm {17 – 26 in. lbs.}

Tightening torque:
30 – 45 Nm
{260 – 390 in. lbs.}

Fix the brake arm of the Inter-M brake securely to the
chainstay with the brake arm clip.

Brake arm clip

Chainstay

Brake arm

Note:

When installing a part such as a mudguard stay to
the hub axle, install in the order shown in the
illustration below.

Non-turn washer

Washer

Cap nut

Carrier stay

Mudguard stay

If excessive force is
applied to the brake
arm, the wheel will
become difficult to
turn. Make sure that
you don't apply
excessive force
when installing.

Install the brake arm of the Inter-M brake to the
chainstay with the brake arm clip, provisionally tighten
the clip screw and clip nut, and then tighten the brake
unit fixing nut.

Tightening torque:
20 – 25 Nm {174 – 217 in. lbs.}

Brake unit fixing nut

Brake arm clip

Chainstay

Brake arm

3.

Note:

If the brake arm is in the incorrect position as
shown in the illustration so that it cannot be
provisionally installed to the chainstay, loosen the
brake unit fixing nut and turn the brake arm. Then,
after provisionally securing the brake arm to the
chainstay, tighten the brake unit fixing nut.

Cassette joint

Groove of fork end

Chainstay

Non-turn
washer
(for right side)

Installation of the hub to the frame

Mount the chain on the sprocket, and then set the hub
axle into the fork ends.

Hub axle

Fork end

The projecting parts should be
on the fork end side.

Install the non-turn washers so that the
projecting parts is securely in the fork end
grooves on either side of the hub axle.

Different types of left and right non-turn washers
are available for use with standard and reversed
fork ends. Use whichever non-turn washers are
suitable.

Place the non-turn washers onto the right side and left
side of the hub axle. At this time, turn the cassette joint
so that the projecting parts of the non-turn washers fit
into the grooves of the fork ends. If this is done, the
cassette joint can be installed so that it is almost parallel
to the chainstay.

Mark

Non-turn washer (for left side)

Cassette joint fixing ring

Cassette joint
fixing ring

Cassette joint pulley

Align the
yellow marks
to install.

Install the driver cap to the driver on the right side of the
hub body.

2.

Turn the cassette joint pulley in the direction of the
arrow in the illustration to align the red marks on the
pulley and the bracket. With the cassette joint in this
condition, install it so that the red mark on the
cassette joint is aligned with the red mark on the right
side of the hub body.

Pulley

Bracket

Cassette joint

Driver cap

Driver cap

Driver

Should be aligned

Note the
direction

Secure the cassette joint to the hub with the cassette
joint fixing ring. When installing the cassette joint fixing
ring, align the yellow mark with the yellow mark on
the cassette joint pulley, and then turn the cassette joint
fixing ring 45° clockwise.

Installation of the cassette joint to
the hub

Fit the cassette joint
bracket securely.

Turn 45°

Align the red
marks to install.

Align the red
marks to install.

Inter-8 Hub

Cassette joint

20

38

CJ-8S20

JAPAN

LOCK

2 mm Allen key
or #14 spoke

Pulley hole

Turn the
pulley

Pull out from
the outer
casing holder

CJ-8S20

JAPAN

LOCK

3

1

Remove the inner
cable fixing bolt unit

2

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

C R

V

V

C R

C R

V

V

C R

CJ-8S

20

JA
PAN

LOCK

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

CJ-8S20

J
AP

AN

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

1

2

SI-6J30A

SB-8S20
BL-IM60
CJ-8S20

10.

2

1

1

2

3

5.

7.

3

3

1

1

2

2

CJ-8S20

JAPAN

LOCK

3

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

CJ-8S20

JAPAN

LOCK

Revo-shift Lever

Cassette Joint

Brake Lever

Be sure to shift the lever one gear at a time, and
reduce the force being applied to the pedals
during shifting. If you try to force operation of the
shifting lever while the pedals are being turned
strongly, your feet may come off the pedals and
the bicycle may topple over, which could result
in serious injury.

Pedaling becomes heavier

Indicator moves toward

8

Indicator moves toward

1

Pedaling becomes lighter

Indicator

Revo-shift lever

General Safety Information

CAUTION

WARNING

– To avoid serious injuries:

– To avoid serious injuries:

NOTE:

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

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

Obtain and read the service instructions
carefully prior to installing the parts. Loose,
worn, or damaged parts may cause serious
injury to the rider.
We strongly recommend only using genuine
Shimano replacement parts.

It is important to completely understand the
operation of your bicycle's brake system.
Improper use of your bicycle's brake system
may result in a loss of control or an accident,
which could lead to severe injury. Because
each bicycle may handle differently, be sure to
learn the proper braking technique (including
brake lever pressure and bicycle control
characteristics) and operation of your bicycle.
This can be done by consulting your
professional bicycle dealer and the bicycle's
owners manual, and by practicing your riding
and braking technique.

These brake levers are equipped with a mode
switching mechanism to make them
compatible with cantilever brakes and Roller
Brakes or V-Brakes with power modulator.

Use the brake levers with mode switching
mechanism in the combinations given above.

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

Technical Service Instructions

Be sure to read these service instructions in
conjunction with the service instructions for
the Inter-8 hub before use.

Revo-shift lever operation

Mode position

Applicable brake

The V indicates the mode
position for compatibility
with V-Brakes with power
modulator.

V position

C/R position

The C indicates the mode
position for compatibility
with cantilever brakes.

The R indicates the mode
position for compatibility
with Roller Brakes.

If the incorrect mode is selected it
may cause either excessive or
insufficient braking force to occur,
which could result in dangerous
accidents.
Be sure to select the mode in
accordance with the instructions
given in the table below.

Tighten

Tighten

Handlebar

Half grip

5 mm Allen key

Clamp bolt

22.2 mm

22.2 mm

In case of using Shimano
half grip, the straight
section of the handlebar
should be 166 mm or more
in length; attach the Revo­shift lever to this straight
section.

Tightening torque:
6 – 8 Nm {60 – 80 kgfcm}

Leave a gap of 0.5 mm
between the Revo-shift
lever and the half grip.

Installation of the lever

Install the lever as shown in the illustration.

5 mm Allen key

Clamp bolt

Grip

V-Brakes with power
modulator

Cantilever brakes

Roller Brakes

Note:

If reusing the cable, refer to steps 7 to 9 in
"Installation of the shifting cable".

Disconnect the cable from the cassette joint
when removing the rear wheel from the
frame.

1

Set the Revo-shift lever to .

1.

Pull the outer casing out from the outer
casing holder of the cassette joint, and then
remove the inner cable from the slit in the
bracket.

2.

Remove the inner cable fixing bolt unit from
the cassette joint pulley.

3.

Disconnecting the shifting cable when

removing the rear wheel from the frame

Cassette joint

Inner cable fixing bolt unit

Cassette joint pulley

Remove from
the slit

Pull out from outer
casing holder

Bracket

Slit

Set to

1

If it is difficult to pull the outer casing out
from the outer casing holder of the cassette
joint, insert a 2 mm Allen key or a #14
spoke into the hole in the cassette joint
pulley, and then turn the pulley to loosen
the inner cable. Then remove the inner
cable fixing bolt unit from the pulley first,
and after this remove the outer casing from
the outer casing holder.

Outer casing holder

CJ-8S20

JAPAN

2

1

Installation of the shifting
cable

Use a shifting cable with one inner cable drum.

Cable with one inner cable drum /
SIS-SP40 (4 mm dia.)

1.

Set to

1

Cover fixing screw

Upper cover

Hole in cable adjustment bolt

Loosen the cover fixing screw, and then remove
the upper cover.

2.

Pass the inner cable through the hole in the cable
adjustment bolt. Next, hook the inner cable into
the groove of the pulley, and pull the inner cable
so that the inner cable drum fits into the hole in
the pulley.

3.

Revo-shift lever side

Groove in pulley

Hole in pulley

Cover fixing screw

Upper cover

Replace the upper cover and tighten the cover
fixing screw.

4.

101 mm

Gap in pulley

Bring the cable around to the cassette joint pulley,
hold so that the inner cable fixing nut is facing to
the outside (toward the fork end), and then slide
the flats part of the inner cable fixing washer into
the gap in the pulley.

Flats part of inner
cable fixing washer

Inner cable
fixing nut

Pulley

6.

After checking that the end of the outer casing is
sitting securely in the cable adjustment bolt of the
Revo-shift lever, attach the inner cable fixing bolt
unit to the inner cable.

Cassette joint side

Inner cable fixing bolt unit

10 mm

Note: Do not use this inner cable fixing bolt

unit with the CJ-4S30 cassette joint.

Inner cable fixing nut

Inner cable fixing
washer

(Black)

Inner cable fixing bolt

Pass the inner cable through the hole.

Pull the inner cable while attaching
the inner cable fixing bolt unit.

Tightening torque:
4 – 6 Nm {40 – 60 kgfcm}

Pulley

Bracket

Guide

9.

OK Not OK

Secure the cable to the frame with the outer
casing bands.

10 cm

10 cm

15 cm

Turn the
cable 60

Hook

8.

Turn the cable 60 counterclockwise and attach it
to the hook.

Attach the inner cable to the pulley as shown in
the illustration, pass the inner cable through the
slit in the cassette joint bracket, and then insert
the end of the outer casing securely into the outer
casing holder.

Inner cable

Slit

Outer casing holder

Pass through
the slit.

Note:

Check that the inner cable is correctly seated
inside the pulley guide.

If first inserting the outer casing into the
outer casing holder is easier, then first insert
the outer casing into the outer casing holder,
and then insert a 2 mm Allen key or a #14
spoke into the hole in the cassette joint
pulley, and then turn the pulley so that the
inner cable fixing bolt unit fits into the gap in
the pulley.

Hole in pulley

Insert into the
outer casing
holder

Insert the inner cable
fixing bolt unit

Guide

Outer casing bands

Bracket

Insert into the
outer casing
holder.

2 mm Allen key
or #14 spoke

Turn the
pulley

These service instructions explain 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.

Adjusting the cassette joint

Set the Revo-shift lever to .
Check to be sure that the yellow setting lines on
the cassette joint bracket and pulley are aligned at
this time.

After adjusting the cassette joint, cut off the
excess length of inner cable and then install the
inner end cap.

4

Inner end cap

Cable adjustment bolt

Cassette joint
pulley

Cassette joint
pulley

Yellow setting lines

15 – 20 mm

Should be straight

Should be straight

When bicycle is upside down

When bicycle is standing up

If the yellow setting lines are not aligned,
turn the cable adjustment bolt of the Revo­shift lever to align the setting lines. After this,
move the Revo-shift lever once more from
to and then back to , and then
re-check to be sure that the yellow setting
lines are aligned.

These service instructions are printed on recycled paper.

Please note: Specifications are subject to change for
improvement without notice. (English)

The yellow setting lines on the cassette joint
are located in two places. Use the one that
is easiest to see.

2.

1.

Cassette joint bracket

Cassette joint bracket

Set to

4

Pass the inner cable through the SIS-SP40 outer
casing through the end with the plastic cap.

If cutting the outer casing, cut it near the end
with the plastic cap while the cap is still
attached. Then make the cut end perfectly
round and attach the plastic cap.

(Lever side)

Remove the plastic cap.

Make the cut end
perfectly round.

Attach the plastic cap.

Aluminum cap

Plastic cap

Plastic cap

1

Set the Revo-shift lever to .

4 41

One Holland Irvine CA 92618 U.S.A. Phone [phone]

Industrieweg 24 NL-8071 CT Nunspeet‚ Holland Phone [phone]

3-77 Oimatsucho‚ Sakai‚ Osaka‚ Japan Phone [phone]

Turn the Revo-shift lever to shift to each of the eight
gears.

Mar. 2003 by Shimano Inc. PIT. SZK. Printed in Japan

C