Shimano FC-M771-K,FC-M770 Service Instructions Manual

Bracket Type

Band Type

Technical Service Instructions SI-1J10A-002

General Safety Information

Specifications

Installation of the Front Chainwheel

WARNING

• The two left crank arm mounting bolts should be tightened alternately in stages rather
than each bolt being fully tightened all at once. Use a torque wrench to check that the
final tightening torques are within the range of 12 - 14 N·m.
Furthermore, after riding approximately 100 km (60 miles), use a torque wrench to re­check the tightening torques.
It is also important to periodically check the tightening torques.
If the tightening torques are too weak or if the mounting bolts are not tightened
alternately in stages, the left crank arm may come off and the bicycle may fall over.

• Before riding, you should carefully check your crankset to make sure that there are no
cracks, and if you find any sign of a crack or any other unusual condition, do NOT use
the bicycle.

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

• 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 cause serious injury.

• If the inner cover is not installed correctly, the axle may rust and become damaged,
and the bicycle may fall over and serious injury may occur as a result.

• 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

• Make sure that the chainring combination matches the front chainwheel tooth
configuration in the Product specifications table. If other combinations are used, the
distance between the chainrings will be incorrect and the chain might slip off and get
caught in between them.

• 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 bottom bracket shell is not parallel, gear
shifting performance will drop.

• Before riding the bicycle, check that there is no play or looseness in the connection.
Also, be sure to retighten the crank arms and pedals at periodic intervals.

• If a squeaking noise is heard coming from the bottom bracket axle and the left crank
arm connector, apply grease to the connector and then tighten it to the specified
torque.

• If you feel any looseness in the bearings, the bottom bracket should be replaced.

• In addition, if pedaling performance does not feel normal, check this once more.

• Do not wash the bottom bracket with high-pressure jets of water.

• Apply grease to the left and right adapters before installing them.

• To ensure the best performance, be sure to use only the specified type of chain. The
wide type of chain cannot be used.

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

• You should periodically wash the chainrings in a neutral detergent and then lubricate
them again. In addition, cleaning the chain with neutral detergent and lubricating it can
be an effective way of extending the useful life of the chainrings 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 installation, adjustment, maintenance or
operation, please contact a professional bicycle dealer.

■ Follow the procedure in the figure.

1, 2 Use the special tool TL-FC32/36 to install the right adapter (counterclockwise thread) and the left

adapter (clockwise thread).
Tightening torque: 35 - 50 N·m {305 - 435 in. lbs.}

3 Insert the right crank unit.

4 Set section A of the left crank into the axle of the right crank unit where the groove is wide.

5 Use the TL-FC16/18 to tighten the cap.

Tightening torque: 0.7 - 1.5 N·m {6 - 13 in. lbs.}

6 Push in the stopper plate and check that the plate pin is securely in place, and then tighten the bolt

of the left crank arm. (5 mm Allen key)

Note : Each of the bolts should be evenly and equally tightened to 12 - 14 N·m {106 - 122 in. lbs.}.

Front
chainrings

Rear
sprockets

■ Spacer installation method

1 Check whether the width of the bottom bracket shell

is 68 mm or 73 mm.

2 Next, install the adapter while referring to the

illustrations below.

68mm
73mm

Model number

Chainwheel tooth combination

Bolt circle diameter

Crank arm length

Chain line

Bottom bracket shell width

Thread dimensions

5

6

2

4

1

3

TL-FC16

TL-FC32

Stopper plate

Plate pin

Push up

Note :

Set the stopper plate in
the right direction as
shown in illustration.

Apply grease to the left
and right adapters
before installing them.

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

* Service Instructions in further languages are available at : http://techdocs.shimano.com

These service instructions are printed on recycled paper.
Please note: specifications are subject to change for improvement without notice.(English) © May 2009 by Shimano Inc. XBC SZK Printed in Japan.

2.5 mm 1.8 mm 0.7 mm

Spacer

FAFBF

C

<

FC-M770

>

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

For bracket type

Install as shown in the
illustration.

Bolt

AdapterAdapter

Front Derailleur

Front Chainwheel

Tightening torque :

35 - 50 N·m {305 - 435 in. lbs.}

Band Type

Bracket Type

<

FC-M771-K

>

73 mm

F

A

68 mm

68 mm

BB mount-type
bracket

73 mm

F

A

F

A

F

A

F

A

F

A

68 mm

68 mm

Chaincase stay

73 mm

73 mm

68 mm

BB mount-type
bracket

73 mm

F

A

F

A

FAF

C

F

C

FCF

B

F

A

F

A

F

A

F

A

F

A

FC-M770

44-32-22T

104 mm / 64 mm

165 mm, 170 mm, 175 mm, 180 mm

50 mm

68, 73 mm

BC1.37 (68, 73 mm)

FC-M771-K

48-36-26T

104 mm / 64 mm

165 mm, 170 mm, 175 mm, 180 mm

50 mm

68, 73 mm

BC1.37 (68, 73 mm)

Chaincase Stay Type

FC-M770 / FC-M771-K

SI-1J10A-002-00

Wide groove

area

(A)

Bottom bracket shell

Inner cover