DIRTBIKE

http://www.adbmag.com APRIL 2016 | 117

OILY

TERMS

Q Oil viscosity refers

to the thickness of the

oil. Damping oils are

typically thinner than

other oils. Changes

in oil viscosity affect

compression and

rebound damping.

Thick oils will increase

damping, but are more

likely to cavitate. The

higher the oil viscosity,

the more it will protect

moving parts.

QCavitation is the

term used when the

oil becomes foamy or

creates air bubbles.

Cavitation causes

your oil to fade in the

same way oils with a

low viscosity index do.

Most suspension oils

will consist of an anti-

foaming agent to reduce

cavitation. Normally,

thick oils have a higher

tendency to cavitate

than thin oils.

DO

Q Use clean tools and a

clean work space while

working on a fork.

QIf you are adding oil,

use the same weight

oil as that already in

the fork.

Q Always check

the manufacturer’s

specifications on

oil heights before

adjusting.

DON’T

Q Over-tighten the

damper rod. It only

needs the locknut to be

nipped up snuggly.

QUse any other oil,

apart from specific

motorcycle fork oil.

Q Drop any spring

preload washers when

removing the spring

from the fork.

8 POUR IT IN

If you want to raise the oil height, pour some
extra oil into the fork tube and then suck out
the excess with the syringe until you reach
the required oil height.

9 TEST RIDE

Once your oil heights are set, slide the
springs back into the fork legs, refit both fork
caps and slide the fork back into the bike.
Take your machine for a test ride to make
sure the fork’s performance is where you want
it to be.
Technical Editor Mat Boyd

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OIL HEIGHTS

For beginner riders or riders

who weigh under 80kg, I

recommend running a 4CS fork oil

height of 100mm but for experienced

riders, riders who are riding at higher

speeds, like you would in desert

races, or riders over 80kg then I

recommend a height of 90mm.