Shimano SG-8R20 Service Instructions

General Safety Information
WARNING
– To avoid serious injuries:
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.
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.
SG-8R20
SG-8R25
CJ-8S20
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.
Installation of the cassette joint to
the hub
1.
Install the driver cap to the driver on the right side of the
hub body.
Driver cap
Driver
Driver cap
t
SI-34R0B
Inter-8 Hub
Cassette joint
Note the
direction