2. The level section of the chain guide outer plate should be
directly above and parallel to the largest chainring.
3. Secure using a 5mm Allen key.
When installing the components to carbon frame/handle bar
surfaces, verify with the manufacturer of the carbon
frame/parts for their recommendation on tightening torque in
order to prevent over tightening that can cause damage to the
carbon material and/or under tightening that can cause lack of
fixing strength for the components.
Chainwheel
(largest chainring)
Chain guide
Tightening torque:
5 - 7 N·m
{44 - 60 in. lbs.}
4. Top adjustment
Set so that the clearance between the chain guide outer
plate and the chain is 0 - 0.5 mm.
* 1/8 turn of adjustment screw (45 degrees) = 0.4 mm
movement of front derailleur
Tighten the top adjustment screw clockwise
(about 1/4 turn).
Loosen the top adjustment screw
counterclockwise (about 1/8 turn). If it still
does not solve the problem, adjust the cable
tension again.
Loosen the low adjustment screw
counterclockwise (about 1/8 turn).
Tighten the low adjustment screw clockwise
(about 1/2 turn).
1. Adjust so that the clearance between the chain guide outer
plate and the large gear is 1 - 3 mm before installing.
Te c h n i c a l Ser vice I n s t r uctions SI-5LB0A-002
General Safety Information
QObtain 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.
QObtain 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.
QUse the CN-7900 in combination with the chain. If a 10-speed chain for
components such as the CN-7801 or CN-6600 is used, the chain may fall off and
the bicycle may suddenly fall over, and serious injury may occur.
QBe careful not to let the cuffs of your clothes get caught in the chain while riding,
otherwise you may fall off the bicycle.
QRead these Technical Service Instructions carefully, and keep them in a safe place for
later reference.
Note
QIf gear shifting operations cannot be carried out smoothly, clean the derailleur and
lubricate all moving parts.
QIf the amount of looseness in the links is so great that adjustment is not possible, you
should replace the derailleur.
QFor smooth operation, use the specified outer casing and the bottom bracket cable
guide.
QGrease the inner cable and the inside of the outer casing before use to ensure that
they slide properly.
Q
Parts are not guaranteed against natural wear or deterioration resulting from normal use.
QFor maximum performance we highly recommend Shimano lubricants and
maintenance products.
QFor any questions regarding methods of installation, adjustment, maintenance or
operation, please contact a professional bicycle dealer.
WARNING
FD-7900
Please note: specifications are subject to change for improvement without notice. (English)
©Sep.2008 by Shimano Inc. XBC SZK Printed in Japan.
SIS adjustment
1. Low adjustment
Set so that the clearance between the chain guide inner
plate and the chain is 0 - 0.5 mm.
* 1/8 turn of adjustment screw (45 degrees) = 0.4 mm
movement of front derailleur
To improve gear shifting performance, the SIS adjustment method for the
FD-7900 front derailleur is slightly different from previous derailleurs.
In addition, the trimming mechanism has also been abolished in order to
improve shifting performance.
2. Connection and securing of cable
While pulling the inner cable, tighten the wire fixing bolt with a 5 mm
allen key to secure the cable.
Largest
sprocket Inner ring
Smallest
sprocket Outer ring
Low adjustment
screw
Chain guide
inner plate
Chain
Pull
Tightening torque:
6 - 7 N·m {52 - 60 in. lbs.}
After taking up the initial slack in the cable,
re-secure to the front derailleur as shown in
the illustration.
3. Adjustment of the cable tension
(1) Set the chain to the largest rear
sprocket, and shift the front to
top gear.
(2) Adjust the clearance (by using the
cable-adjustment bolt) of the chain
and chain guide to the minimum (0 -
0.5 mm).
Top adjustment
screw
Chain guide
outer plate
Chain
Chain guide
inner plate
Chain
Clearance:
0 - 0.5mm
Be sure to read these service instructions in conjunction with the service instructions for the
ST-7900 / SL-7900 / SL-BS79 before use.
Outer casing adjustment bolt
Largest
sprocket Outer ring
Largest
sprocket Outer ring
Front shifting
Lever [
b
From large chainring
to small chainring
Lever [
a
From small chainring
to large chainring
Lever [
a
Lever [
b
Type Band type / Brazed on type
Front derailleur installation band diameter S (28.6mm), M (31.8mm), L (34.9mm)
Chainstay angle (C)61° - 66°
Front chainwheel tooth difference 16 teeth or less
Chain line 43.5mm
In order to realize the best performance, we recommend that the following
combination be used.
Series DURA-ACE
Shifting lever ST-7900 / SL-7900 / SL-BS79
Outer casing SP41
Gears 20
Front derailleur FD-7900
Front chainwheel FC-7900
Rear derailleur RD-7900
Freehub FH-7900
Cassette sprocket CS-7900
Chain CN-7900
Bottom bracket cable guide SM-SP17
Installation of the front derailleur
Clearance: 1 - 3 mm
Chain guide outer plate
Specifications
5. Troubleshooting chart
After completion of steps 1 - 4, move the shifting lever to check the shifting.
(This also applies if shifting becomes difficult during use.)
If the chain falls to the crank side
If shifting is difficult from the small chainring to the
large chainring
If shifting is difficult from the large chainring to the
small chainring
If the chain falls to the bottom bracket side.
SI-5LB0A-002-00
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