Specialized Roubaix Comp Road Manual De Instrucciones página 32

The function of the rear derailleur is to move the drive chain from one gear sprocket
to another. The smaller sprockets on the gear cluster produce higher gear ratios.
Pedaling in the higher gears requires greater pedaling effort, but takes you a greater
distance with each revolution of the pedal cranks. The larger sprockets produce lower
gear ratios. Using them requires less pedaling effort, but takes you a shorter distance
with each pedal crank revolution. Moving the chain from a smaller sprocket of the
gear cluster to a larger sprocket results in a downshift. Moving the chain from a larger
sprocket to a smaller sprocket results in an upshift. In order for the derailleur to move
the chain from one sprocket to another, the rider must be pedaling forward.
c. Shifting the Front Derailleur:
The front derailleur, which is controlled by the left shifter, shifts the chain
between the larger and smaller chainrings. Shifting the chain onto a smaller
chainring makes pedaling easier (a downshift). Shifting to a larger chainring
makes pedaling harder (an upshift).
d. Which gear should I be in?
The combination of largest rear and
smallest front gears (fig. 16) is for the
steepest hills. The smallest rear and
largest front combination is for the
greatest speed. It is not necessary to
shift gears in sequence. Instead, find
the "starting gear" which is right for
your level of ability — a gear which is
hard enough for quick acceleration
but easy enough to let you start
from a stop without wobbling — and
experiment with upshifting and
downshifting to get a feel for the
different gear combinations. At first,
practice shifting where there are no obstacles, hazards or other traffic, until
you've built up your confidence. Learn to anticipate the need to shift, and shift
to a lower gear before the hill gets too steep. If you have difficulties with shifting,
the problem could be mechanical adjustment. See your dealer for help.
WARNING: Never shift a derailleur onto the largest or the smallest
sprocket if the derailleur is not shifting smoothly. The derailleur
may be out of adjustment and the chain could jam, causing you to
lose control and fall.
e. What if it won't shift gears?
If moving the shift control one click repeatedly fails to result in a smooth shift
to the next gear chances are that the mechanism is out of adjustment. Take the
bike to your dealer to have it adjusted.
If your bicycle has an internal gear hub drivetrain, the gear changing
mechanism will consist of:
• a 3, 5, 7, 8, 12 speed or possibly an infinitely variable internal gear hub
• one, or sometimes two shifters
2. How an internal gear hub drivetrain works
Fig. 16
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