Honda CRF250X, Руководство пользователя и соревновательное пособие

Страница: 127 / 180

Adjustments for Competition
121
Rear Suspension Adjustments
Because of the great absorption quality of the
shock bumper rubber, it may be difficult for you
to notice when your motorcycle’s suspension is
bottoming. Some riders may think the damping
or perhaps the leverage ratio is too harsh. In
reality, the problem is most likely insufficient
spring pre-load or a spring that is too soft. Either
situation prevents utilizing the full travel.
Keep in mind that a properly adjusted suspension
system may bottom slightly every few minutes at
full speed. Adjusting the suspension to avoid this
occasional bottoming may cost more in overall
suspension performance than it is worth.
A spring that is too firm for your weight will not
allow the rear tire to hook up under acceleration
and will pass more bumps on to you.
6. Calculate the free sag dimension.
To do this, subtract the loaded without rider
dimension (step 5) from the unloaded
dimension (step 2).
Free sag indicates the distance your rear
suspension should sag from the weight of the
sprung portion of your motorcycle.
With the spring pre-load set to obtain the
proper race sag, the rear suspension should
sag 10 to 25 mm (0.4 to 1.0 in).
If the rear of your motorcycle sags more than
25 mm (1.0 in) from its own weight, the
spring is too stiff for your weight. It is not
compressed enough, even though you have
the proper race sag adjustment. As a result,
the rear suspension will not extend as far as it
should.
Spring Rates
If you are lighter or heavier than the average
rider and cannot set the proper ride height
without altering the correct spring pre-load,
consider an aftermarket shock absorber spring.
A spring that is too soft for your weight forces
you to add excessive spring pre-load to get the
right race sag and, as a result, the rear end of the
motorcycle is raised. This can cause the rear
wheel to unload too much in the air and top out
as travel rebounds. The rear end may top out
from light braking, or kick sideways over lips
and square-edged terrain. It may even top-out
when you dismount your motorcycle.