52
a
b
c
d
Adjusting the front derailleur
The range within which the front derailleur
(a)
keeps
the chain on the chainwheel without itself touching
the chain is very small. If the chain tends to jump off
the chainwheel, you will need to reduce the move-
ment range in the same way as with the rear derail-
leur, i.e. by turning the limit screws marked “H” and
“L”
(b)
.
Start by shifting to the large chainwheel (front) and
the smallest sprocket (rear)
(c)
. Turn in the outer limit
screw (“H“) exactly to the point where the chain does
not touch the front derailleur, even under heavy load.
And only at the point where the chain does not move
from the middle to the large chainwheel any more,
the limit screw can be released a little.
Continue by shifting to the smallest chainwheel (front)
and the biggest sprocket (rear). Turn in the inner limit
screw (“L“) exactly to the point where the chain does
not touch the front derailleur. And only at the point
where the chain does not move from the large or
middle to the small chainwheel any more, the limit
screw can be released a little.
This adjustment prevents the chain from falling off
which would suddenly interrupt the drive involving
the risk of an accident.
The parallelism to the longitudinal axis must be
checked as well. Otherwise the crank may collide
with the front derailleur tearing it off in the worst case.
Shimano front derailleurs of the latest generation
have a set screw for adjustment.
In cases of doubt this adjustment is a job best left to
your CENTURION dealer.
As with the rear derailleur, the cable of the front de-
railleur is subject to lengthening which leads to a
reduced precision in gear changing. If necessary,
shift to the small chainwheel and increase the ten-
sion of the Bowden cable by turning the adjusting
bolt through which it passes at the entry to the down
tube cable stop.
G
Always check after an accident whether
the guide plates of the front derailleur
are still parallel to the chainwheels
(d)
.
Make sure they do not touch the large chain-
wheel. This would jam the drive or make the
crank drag. Risk of an accident!
G
Adjusting the front derailleur is a very
delicate job. Improper adjustment can
cause the chain to jump off, thus inter-
rupting the power train. Risk of an accident!
A
Be sure to do a test ride in an unfre-
quented place after adjusting the gears.
Summary of Contents for ROAD BIKE ISO 4210-2
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