YAMAHA WR 450F 2016 Owners Manual

4
TUNING
CHASSIS.......................................................................................................... 4-1
SELECTION OF THE SECONDARY REDUCTION RATIO
(SPROCKET) ............................................................................................ 4-1
DRIVE AND REAR WHEEL SPROCKETS SETTING PARTS .................. 4-1
TIRE PRESSURE............................. .......................................................... 4-1
FRONT FORK SETTING............................................................................ 4-2
CHANGE IN AMOUNT AND CHARACTERISTICS OF FORK OIL............ 4-2
SETTING OF SPRING AFTER REPLACEMENT ...................................... 4-2
FRONT FORK SETTING PARTS............................................................... 4-3
REAR SUSPENSION SETTING ................................................................ 4-3
CHOOSING SET LENGTH ........................................................................ 4-3
SETTING OF SPRING AFTER REPLACEMENT ...................................... 4-4
REAR SHOCK ABSORBER SETT ING PARTS ......................................... 4-4
SUSPENSION SETTING (FRONT FORK)................................................. 4-6
SUSPENSION SETTING (REAR SHOCK ABSORBER) ........................... 4-7

CHASSIS
4-1
EAS2GC1136
CHASSIS
EAS2GC1137SELECTION OF THE SECONDARY REDUC-
TION RATIO (SPROCKET)
reduction ratio>
• It is generally said that the secondary gear ra-tio should be reduced for a longer straight por-
tion of a speed course and should be
increased for a course with many corners. Ac-
tually, however, as the speed depends on the
ground condition of the day of the race, be
sure to run through the circuit to set the ma-
chine suitable for the entire course.
• In actuality, it is very difficult to achieve set- tings suitable for the entire course and some
settings may be sacrificed. Thus, the settings
should be matched to the portion of the
course that has the greatest effect on the race
result. In such a case, run through the entire
course while making notes of lap times to find
the best balance; then, determine the second-
ary reduction ratio.
• If a course has a long straight portion where a machine can run at maximum speed, the ma-
chine is generally set such that it can develop
its maximum revolutions toward the end of the
straight line, with care taken to avoid the en-
gine over-revving.
TIP
Riding technique varies from rider to rider and
the performance of a machine also vary from
machine to machine. Therefore, do not imitate
other rider’s settings from the beginning but
choose your own setting according to the level
of your riding technique.
EAS2GC1138DRIVE AND REAR WHEEL SPROCKETS
SETTING PARTS
EAS2GC1139TIRE PRESSURE
Tire pressure should be adjusted to suit the
road surface condition of the circuit.
• Under a rainy, a muddy, a sandy, or a slippery condition, the tire pressure should be lower
for a larger area of contact with the road sur-
face.
Secondary reduction ratio = Number of
rear wheel sprocket teeth/Number of
drive sprocket teeth
Secondary reduction ratio 3.846 (50/13)
Part name Type Part number
Drive sprocket “1”
(STD) 13T 9383E-13233
Rear wheel
sprocket “2”
48T 5GS-25448-50
(STD) 50T 5TJ-25450-80 52T 5TJ-25452-80
Standard tire pressure 100 kPa (1.00 kgf/cm
2,15 psi)
Extent of adjustment 60–80 kPa (0.60–0.80 kgf/cm
2, 9–
12 psi)

CHASSIS
4-2
• Under a stony or a hard road condition, the tire pressure should be hi gher to prevent a flat
tire.
EAS2GC1140FRONT FORK SETTING
The front fork setting should be made depend-
ing on the rider’s feeli ng of an actual run and
the circuit conditions.
The front fork setting includes the following
three factors:
1. Setting of air spring characteristics • Change the fork oil amount.
2. Setting of spring preload • Change the spring.
3. Setting of damping force
• Change the compression damping force.
• Change the rebound damping force.The spring acts on the load and the damping
force acts on the cushion travel speed.
EAS2GC1141CHANGE IN AMOUNT AND CHARACTERIS-
TICS OF FORK OIL
Damping characteristic near the final stroke
can be changed by changing the fork oil
amount.
EWA
WARNING
Adjust the oil amount in 5 cm3 (0.2 US oz,
0.2 Imp.oz) increments or decrements. Too
small oil amount causes the front fork to
produce a noise at full rebound or the rider
to feel some pressure on his hands or body.
Alternatively, too large oil amount will
cause the air spring characteristics to have
a tendency to be stiffer with the consequent
deteriorated performance and characteris-
tics. Therefore, adjust the front fork within
the specified range.
EAS2GC1142SETTING OF SPRING AFTER REPLACE-
MENT
As the front fork setting can be easily affected
by the rear suspension, take care so that the
front and the rear are balanced (in position etc.)
when setting the front fork.
1. Use of soft spring
• Change the rebound damping force.Turn out one or two clicks.
• Change the compression damping force.
Turn in one or two clicks.
TIP
Generally a soft spring gives a soft riding feel-
ing. Rebound damping tends to become stron-
ger and the front fork may sink deeply over a
series of gaps.
2. Use of stiff spring• Change the rebound damping force.
Turn in one or two clicks.
• Change the compression damping force. Turn out one or two clicks.
Extent of adjustment
100–120 kPa (1.00–1.20 kgf/cm
2,
15–18 psi)
Standard oil amount 345 cm
3 (11.66 US oz, 12.14
lmp.oz)
Extent of adjustment 300–365 cm
3 (10.14–12.34 US
oz, 10.58–12.87 Imp.oz)
A. Air spring characteristics in relation to oil amount change
B. Load
C. Stroke
1. Max. oil amount
2. Standard oil amount
3. Min. oil amount

CHASSIS
4-3
TIP
Generally a stiff spring gives a stiff riding feel-
ing. Rebound damping tends to become weak-
er, resulting in lack of a sense of contact with
the road surface or in a vibrating handlebar.
EAS2GC1143FRONT FORK SETTING PARTS
• Front fork spring “1”
TIP
The I.D. mark (slits) “a” is proved on the end of
the spring.
EAS2GC1144REAR SUSPENSION SETTING
The rear shock absorber setting should be
made depending on the rider’s feeling of an ac-
tual run and the circuit conditions.
The rear suspension setting includes the fol-
lowing two factors:
1. Setting of spring preload • Change the set length of the spring.
• Change the spring.
2. Setting of damping force
• Change the rebound damping force.
• Change the compression damping force.
EAS2GC1145CHOOSING SET LENGTH
1. Place a stand or a block under the engine to put the rear wheel above the floor, and mea-
sure the length “a” between the rear wheel
axle center and the rear fender holding bolt.
2. Remove the stand or block from the engine and, with a rider astride the seat, measure
the sunken length “b” between the rear
wheel axle center and the rear fender hold-
ing bolt.
3. Loosen the locknut “1” and make adjustment by turning the adjuster “2” to achieve the
standard figure from the subtraction of the
length “b” from the length “a”.
Type
Spring
rate N/ mm Part number I.D.
Mark
(slits)
SOFT 4.1 2GB-23141-A0 |||
4.2 2GB-23141-B0 ||||
4.3 2GB-23141-C0 |||||
4.4 2GB-23141-D0 |-|
STD 4.5 2GB-23141-40 —
2GB-23141-E0 |-||
STIFF 4.6 33D-23141-30 |-|||
a
1
Standard figure90–100 mm (3.5–3.9 in)

CHASSIS
4-4
TIP
• If the machine is new and after it is broken in, the same set length of the spring may change
because of the initial fatigue, etc. of the
spring. Therefore, be sure to make reevalua-
tion.
• If the standard figure cannot be achieved by adjusting the adjuster and changing the set
length, replace the spri ng with an optional one
and make readjustment.
EAS2GC1146SETTING OF SPRING AFTER REPLACE-
MENT
After replacement, be sure to adjust the spring
to the set length [sunken length 90–100 mm
(3.5–3.9 in)] and set it.
1. Use of soft spring
• Adjust to decrease rebound damping force to compensate for less spring load. Run with
the rebound damping force adjuster one or
two clicks turned out, and readjust it to suit
your preference.
2. Use of stiff spring • Adjust to increase rebound damping force to
compensate for greater spring load. Run
with the rebound damping force adjuster
one or two clicks turned in, and readjust it to
suit your preference.
TIP
Adjusting the rebound damping force will be fol-
lowed more or less by a change in the com-
pression damping force. For correction, adjust
to decrease compression damping force.
EWA
WARNING
When using a rear shock absorber other
than currently installed, use the one whose
overall length “a” does not exceed the stan-
dard as it may result in faulty performance.
Never use one whose overall length is
greater than standard.
EAS2GC1147REAR SHOCK ABSORBER SETTING
PARTS
• Rear shock spring “1”
TIP
• The I.D. mark “a” is marked at the end of the spring.
• Spring specification varies according to the
color of I.D. marks.
Length “a” of standard shock 462.5 mm (18.21 in)
Type Spring
rate N/ mm Part number
I.D.
Mark
SOFT 48
2GB-22212-10
(Blue) Black
50 2GB-22212-00
(Blue) Green
52 1SL-22212-40
(Blue) Yellow
B11-22212-00 (Yellow) Blue
54 1SL-22212-60
(Blue) Pink
B11-22212-10
(Yellow)
STD 56 1SL-22212-20
(Blue) White
B11-22212-20
(Yellow)
STIFF 58
1SL-22212-00
(Blue) Silver
B11-22212-30
(Yellow)
60 1SL-22212-80
(Blue) Brown
B11-22212-40
(Yellow)

CHASSIS
4-5
• Spring preload adjusting positions
TIP
For the spring preload adjustment, refer to “AD-
JUSTING THE REAR SHOCK ABSORBER
ASSEMBLY” on page 3-34.Spring preload adjusting positions
MinimumPosition in which the spring is
turned in 1.5 mm (0.06 in) from
its free length.
Standard Position in which the spring is
turned in 12 mm (0.47 in) from its
free length.
Maximum Position in which the spring is
turned in 18 mm (0.71 in) from its
free length.

CHASSIS
4-6
EAS2GC1148SUSPENSION SETTING (FRONT FORK)
TIP
• If any of the following symptoms is experienced with the standard position as the base, make reset-ting by reference to the adjustment procedure given in the same chart.
• Before any change, set the rear shock absor ber sunken length to the standard figure 90–100 mm
(3.5–3.9 in).
Symptom Section
CheckAdjust
Jump Large
gap Medi-
um
gap Small
gap
Stiff over entire
range Compression
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Oil amount Decrease oil amount by about 5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
Spring Replace with soft spring.
Unsmooth
movement over
entire range Outer tube
Inner tube
Check for any bends, dents,
other noticeable scars, etc. If
any, replace affected parts.
Slide metal Replace with a new one for ex- tended use.
Piston metal Replace with a new one for ex- tended use.
Lower bracket
tightening
torque Retighten to specified torque.
Poor initial
movement Rebound
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Oil seals Apply grease in oil seal wall.
Soft over entire
range, bottom-
ing out Compression
damping force
Turn adjuster clockwise (about
2 clicks) to increase damping.
Oil amount Increase oil amount by about 5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
Spring Replace with stiff spring.
Stiff toward
stroke end Oil amountDecrease oil amount by about
5 cm
3 (0.2 US oz, 0.2 Imp.oz).
Soft toward
stroke end, bot-
toming out Oil amountIncrease oil amount by about 5
cm
3 (0.2 US oz, 0.2 Imp.oz).
Stiff initial
movement Compression
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.

CHASSIS
4-7
EAS2GC1149SUSPENSION SETTING (REAR SHOCK ABSORBER)
TIP
• If any of the following symptoms is experienced with the standard position as the base, make reset-ting by reference to the adjustment procedure given in the same chart.
• Adjust the rebound damping in 2- click increments or decrements.
• Adjust the low compression damping in 1-click increments or decrements.
• Adjust the high compression damping in 1/6 turn increments or decrements.Low front, tend-
ing to lower
front posture
Compression
damping force
Turn adjuster clockwise (about
2 clicks) to increase damping.
Rebound
damping force Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Balance with
rear end Set sunken length for 95–100
mm (3.7–3.9 in) when one
passenger is astride seat (low-
er rear posture).
Oil amount Increase oil amount by about 5 cm
3 (0.2 US oz, 0.2 Imp.oz).
“Obtrusive”
front, tending to
upper front pos-
ture Compression
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Balance with
rear end Set sunken length for 90–95
mm (3.5–3.7 in) when one
passenger is astride seat (up-
per rear posture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about 5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
Symptom Section
Check Adjust
Jump Large
gap Medi-
um
gap Small
gap
Stiff, tending to
sink Rebound
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Spring set
length Set sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spongy and un-
stable Rebound
damping force
Turn adjuster clockwise (about
2 clicks) to increase damping.
Low compres-
sion damping Turn adjuster clockwise (about
1 click) to increase damping.
Spring Replace with stiff spring.
Symptom
Section
Check Adjust
Jump Large
gap Medi-
um
gap Small
gap

CHASSIS
4-8
Heavy and
draggingRebound
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Spring Replace with soft spring.
Poor road grip-
ping Rebound
damping force
Turn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Low compres-
sion damping Turn adjuster clockwise (about
1 click) to increase damping.
High compres-
sion damping Turn adjuster clockwise (about
1/6 turn) to increase damping.
Spring set
length Set sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with soft spring.
Bottoming out High compres-
sion damping
Turn adjuster clockwise (about
1/6 turn) to increase damping.
Spring set
length Set sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with stiff spring.
Bouncing Rebound
damping force
Turn adjuster clockwise (about
2 clicks) to increase damping.
Spring Replace with soft spring.
Stiff travel High compres-
sion damping
Turn adjuster counterclock-
wise (about 1/6 turn) to de-
crease damping.
Spring set
length Set sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with soft spring.
Symptom
Section
CheckAdjust
Jump Large
gap Medi-
um
gap Small
gap

CHASSIS
4-9