SECTION: SECTION: III Fit
11
III. Fit
NOTE: Correct fit is an essential element of bicycling safety, performance
and comfort. Making the adjustments to your bicycle which result in
correct fit for your body and riding conditions requires experience, skill
and special tools. Always have your dealer make the adjustments on your
bicycle; or, if you have the experience, skill and tools, have your dealer
check your work before riding.
Make sure the bike fits. A bike that’s too big or too small is harder to control
and can be uncomfortable.
WARNING:
If your bicycle does not fit properly, you may lose control and
fall. If your new bike doesn’t fit, ask your dealer to exchange it
before
you ride
it.
A. Standover Height
Standover height is the basic element of bike fit
(see Fig. 2). It is the distance from the ground to
the top of the bicycle’s frame at that point
where your crotch would be if you were strad-
dling the bike and standing half way between
the saddle and the handlebars. To check for
correct standover height, straddle the bike while
wearing the kind of shoes in which you’ll be
riding, and bounce vigorously on your heels. If
your crotch touches the frame, the bike is too
big for you. Don’t even ride the bike around the
block. A bike which you ride only on paved
surfaces and never take off-road should give you a minimum standover
height clearance of five centimeters. A bike that you’ll ride on unpaved
surfaces should give you a minimum of seven and a half centimeters of
standover height clearance. And a bike that you’ll use for real mountain
biking on difficult, rough terrain should give you ten centimeters or more
of clearance.
B. Saddle Position
Correct saddle adjustment is an important factor in getting the most perfor-
mance and comfort from your bicycle. If the saddle position is not comfortable
for you, see your dealer, who has the tools and skill to change it.
The saddle can be adjusted in three directions:
1.
Up and down adjustment.
To check for correct saddle height (Fig. 3):
•
sit on the saddle;
•
place one heel on a pedal;
•
rotate the crank until the pedal with your heel on it is in the down
position and the crank arm is parallel to the seat tube.
Fig 2
D. Shifting Gears
Your multi-speed bicycle will have a derailleur drivetrain (See 1. below),
an internal gear hub drivetrain (See 2. below) or, in some special cases, a
combination of the two.
1. How a derailleur drivetrain works
If your bicycle has a derailleur drivetrain, the gear-changing mecha-
nism will have:
• a rear cassette or freewheel sprocket cluster
• a rear derailleur
• usually a front derailleur
• one or two shifters
• one, two or three front sprockets called chainrings
• a drive chain
a. Shifting Gears
The different types of shifters and
their operation are illustrated in Fig-
ures 15 – 20. Identify the shifters on
your bike before reading on. The vo-
cabulary of shifting can be pretty con-
fusing. A downshift is a shift to a
“slower” gear, one which is easier to
pedal. An upshift is a shift to a
“faster”, harder to pedal gear. What’s
confusing is that what’s happening at
the front derailleur is the opposite of
what’s happening at the rear de-
railleur (for details, read the instruc-
tions on Shifting the Rear Derailleur
and Shifting the Front Derailleur be-
low). For example, you can select a gear which will make
pedaling easier on a hill (make a downshift) in one of two
ways: shift the chain down the gear “steps” to a smaller gear
at the front, or up the gear “steps” to a larger gear at the rear.
So, at the rear gear cluster, what is called a downshift looks like
an upshift. The way to keep things straight is to remember that
shifting the chain in towards the centerline of the bike is for
accelerating and climbing and is called a downshift. Moving
the chain out or away from the centerline of the bike is for
speed and is called an upshift.
Whether upshifting or downshifting, the bicycle derailleur
system design requires that the drive chain be moving for-
ward and be under at least some tension. A derailleur will shift
only if you are pedaling forward.
CAUTION:
Never move the shifter while pedaling backward, nor pedal
backwards after having moved the shifter. This could jam the chain and
cause serious damage to the bicycle.
Fig. 15
Fig. 16
Fig. 17
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SECTION: IV Tech
