Chassis; Selection Of The Secondary Reduction Ratio (Sprocket); Drive And Rear Wheel Sprockets Setting Parts - Yamaha YZ450FF 1SL-28199-11 Owner's Service Manual

CHASSIS

EAS1SL5367
SELECTION OF THE SECONDARY REDUC-
EAS1SL5368
TION RATIO (SPROCKET)
Secondary reduction ratio = Number of
rear wheel sprocket teeth/Number of
drive sprocket teeth
Secondary reduction ra-
tio
*For EUR and JPN
<Requirement for selection of secondary gear
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.
DRIVE AND REAR WHEEL SPROCKETS
EAS1SL5369
SETTING PARTS
Drive sprocket "1"
Rear wheel
sprocket "2"
3.692 (48/13)
*3.769 (49/13)
*For EUR and JPN
10-1
Part name Type
(STD) 13T
47T
(STD) 48T
*(STD) 49T
50T
51T
52T
CHASSIS
Part number
9383E-13233
17D-25447-50
17D-25448-50
17D-25449-50
17D-25450-50
17D-25451-50
17D-25452-50