Marzocchi Z3 QR20 User manual

Z3
QR20
(110)
TRAVEL 110
+0.5
0
175
18
426 55
L.MAX=491 L.L.=481 L.MIN=371
248.5
80
26.5
130
110
Ø30
±2
±2
15
20
0
-0.1
+1
0
Ø30
+0.05
0
GENERAL
• The fork is sprung by a mechanical coil system and uses hydraulic
rebound damping.
• Spring pre-load adjustment controlled via external top mount
adjuster, rebound damping adjustment controlled by bottom
adjuster of right fork leg.
• Stanchions fitted into lower Crown by cryofit technique. Full length
bushings guarantee superior rigidity.
• Sliders and arch are an integral assembly for reduced weight and
improved rigidity.
• Parts subjected to friction are cooled and lubricated by a specially
formulated oil.
• QR20 wheel shaft retaining system for special hubs (110-mm stop)
and wheel shafts with 20-mm diameter.
Steer tube: stainless steel or, on request, EASTON aluminum steer
tube available for 1 1/8” diameter, threadless.
Crown: Forged and CNC-machined BAM
❊
aluminum alloy.
Arch: Cast magnesium alloy.
Stanchions: anodized EASTON aluminum with variable butting.
Springs: Constant pitch springs.
Sliders: Forged and CNC-machined BAM
❊
aluminum alloy. Left
slider comes with supports for disc brake caliper.
Slider bushing: Full length guide bushings composed of a copper
base and impregnated with an anti-friction coating.
Seals: Computer designed oil seals guarantee the highest quality
seals available.
Oil: Specially formulated oil which eliminates foaming and viscosity
breakdown while providing complete stiction-free performance.
Fork leg oil: 85 cc (each leg), type EBH 16 - SAE 7.5.
❊
BAM: Bomber Aerospace Material.
Special alloy developed from aerospace material.

Z3
QR20
(130)
TRAVEL 130
+0.5
0
175
18
446 55
L.MAX=511 L.L.=501 L.MIN=371
248.5
80
26.5
130
110
Ø30
±2
±2
Ø30
+0.05
0
15
20
0
-0.1
+1
0
GENERAL
• The fork is sprung by a mechanical coil system and uses hydraulic
rebound damping.
• Spring pre-load adjustment controlled via external top mount
adjuster, rebound damping adjustment controlled by bottom
adjuster of right fork leg.
• Stanchions fitted into lower Crown by cryofit technique. Full length
bushings guarantee superior rigidity.
• Sliders and arch are an integral assembly for reduced weight and
improved rigidity.
• Parts subjected to friction are cooled and lubricated by a specially
formulated oil.
• QR20 wheel shaft retaining system for special hubs (110-mm stop)
and wheel shafts with 20-mm diameter.
Steer tube: stainless steel or, on request, EASTON aluminum steer
tube available for 1 1/8” diameter, threadless.
Crown: Forged and CNC-machined BAM
❊
aluminum alloy.
Arch: Cast magnesium alloy.
Stanchions: anodized EASTON aluminum with variable butting.
Springs: Constant pitch springs.
Sliders: Forged and CNC-machined BAM
❊
aluminum alloy. Left
slider comes with supports for disc brake caliper.
Slider bushing: Full length guide bushings composed of a copper
base and impregnated with an anti-friction coating.
Seals: Computer designed oil seals guarantee the highest quality
seals available.
Oil: Specially formulated oil which eliminates foaming and viscosity
breakdown while providing complete stiction-free performance.
Fork leg oil: 90 cc (each leg), type EBH 16 - SAE 7.5.
❊
BAM: Bomber Aerospace Material.
Special alloy developed from aerospace material.

Z3
QR20
(100)
TRAVEL 100
+0.5
0
175
18
426 55
L.MAX=481 L.L.=471 L.MIN=371
248.5
80
26.5
130
110
Ø30
±2
±2
15
20
0
-0.1
+1
0
Ø30
+0.05
0
SPECIALIZED
GENERAL
• The fork is sprung by a mechanical coil system and uses hydraulic
rebound damping.
• Spring pre-load adjustment controlled via external top mount
adjuster, rebound damping adjustment controlled by bottom
adjuster of right fork leg.
• Stanchions fitted into lower Crown by cryofit technique. Full length
bushings guarantee superior rigidity.
• Sliders and arch are an integral assembly for reduced weight and
improved rigidity.
• Parts subjected to friction are cooled and lubricated by a specially
formulated oil.
• QR20 wheel shaft retaining system for special hubs (110-mm stop)
and wheel shafts with 20-mm diameter.
Steer tube: stainless steel or, on request, EASTON aluminum steer
tube available for 1 1/8” diameter, threadless.
Crown: Forged and CNC-machined BAM
❊
aluminum alloy.
Arch: Cast magnesium alloy.
Stanchions: anodized EASTON aluminum with variable butting.
Springs: Constant pitch springs.
Sliders: Forged and CNC-machined BAM
❊
aluminum alloy. Left
slider comes with supports for disc brake caliper.
Slider bushing: Full length guide bushings composed of a copper
base and impregnated with an anti-friction coating.
Seals: Computer designed oil seals guarantee the highest quality
seals available.
Oil: Specially formulated oil which eliminates foaming and viscosity
breakdown while providing complete stiction-free performance.
Fork leg oil: 85 cc (each leg), type EBH 16 - SAE 7.5.
❊
BAM: Bomber Aerospace Material.
Special alloy developed from aerospace material.

Z3
QR20
INSTRUCTIONS
GENERAL RULES
1. Where specified, assemble and disas-
semble the shock absorption system
usingtheM ARZOCCHI special toolsonly.
2. On reassembling the suspension sys-
tem, always use new seals.
3. Clean all metal parts with a special,
preferablybiodegradablesolvent,such
as trichloroethane or trichloroethylene.
4. Beforereassembling,lubricate allparts
in contact with each other using sili-
conefat sprayor aspecificoil forseals.
5. Always grease the lip seal rings before
reassembling.
6. Use wrenches with metric size only.
Wrenches with inch size might dam-
age the fastening devices even when
theirsizeissimilartothatofthewrenches
in metric size.

Z3
QR20
FAILURES, CAUSES AND REMEDIES
Thisparagraph reports somefailuresthatmay occurwhenusingthe fork.It alsoindicatespossible causes andsuggestsa remedy.Always
refer to this table before doing any repair work.
Oil leaking though the top of slider 1. Oil seal is worn out
2. Stanchion tube is scored
3. Excessive dirt on oil seal
1. Replace oil seal
2. Replace crown/stanchions assembly,
oil seals and dust seals
3. Cleantheoilsealseatandreplaceoilseal
FAILURES CAUSES REMEDIES
Oil leaking through the bottom of slider O-rings at pumping element bottom and
adjusting rod damaged. Replace the O-rings
Fork has not been used for some time and
is locked out Oil seals and dust seals tend to stick to stanchions Raise dust seal and lubricate stanchion tube, dust seal and oil seal
Excessive play of stanchions in the sliders Pilot bushings are worn Replace pilot bushings
Adjuster position does not affect fork op-
eration 1. Dirt inside legs 2. O-ringintopumpingelement damaged. 1. Clean carefully and change oil 2. Replace O-ring.

Z3
QR20
RECOMMENDATIONS FOR
MAINTENANCE
M ARZOCCHI forks are based on advanced
technology,supported byyear-long expe-
rience in the field of professional moun-
tain biking. In order to achieve best re-
sults, we recommend to check and clean
the area below the dust seal and the
stanchion tube after each use and lubri-
cate with silicone oil.
In general, M ARZOCCHI forks can offer top
performance from the start. However, in
some cases a short running-in period is
required (5-10 hours) for inner adjust-
ments. This running-in period will make
fork life longer and ensure fork top per-
formance over time.
IMPORTANT: change oil at least every
100 working hours.
Polished forks should be cleaned with
bodywork polish at regular intervals in
order to preserve their original finish.

Z3
QR20
Nm 12
BD
B
C
A
A
C
DISC BRAKE SYSTEM ASSEMBLY
WARNING: If a disc brake sys-
tem is installed, it is absolutely
forbidden to loosen and remove original
brake supports fixing pins. In fact, apart
from retaining Cantilever or V-brake le-
vers, they also play an important role in
securingsliderbottom toslider-arch mono-
lith. If needed, replace these pins with
screws (part no. 532979QF) available
as spare parts.
Tighten the above screws to 15 Nm.
IMPORTANT: screw and pin threading
is treated to ensure hydraulic seal. Never
reuse screws and pins which have been
removed.
Assembling the brake caliper onto the
slider is a very delicate operation that
should be carried out with extreme care.
Improper assembly might overstress the
caliper supports which might break.
When installing the disc brake system, be
sure to properly follow the instructions
given by the manufacturer.
INSTALLATION
Installing the fork on a bicycle is a very
delicate operation that should be carried
out with extreme care. The installation
should always be checked by one of our
Technical Service Centers.
WARNING: Steer tube/headset
mounting and adjustment must be
carried out in compliance with the head-
set manufacturer’s instructions. Improper
installation may jeopardize the safety of
the rider.
To replace it, contact one of our Technical
Service Centers with the required tools.
WARNING: In case of improper
installation of the steer tube into the
crown, the rider might lose control of his/
her bicycle, thus jeopardizing his/her
safety.
FRONT WHEEL ASSEMBLY
IMPORTANT:fixingthefrontwheelprop-
erly as specified in the instructions given
belowis essential fortheproperoperation
of this fork and all related devices, and
therefore for safe riding. You are advised
to follow these instructions closely.
Slacken the lock nut of the quick release
lever so the hub will fit between the fork
sliders.
Make sure the quick release bushings (A)
are centered to the recesses in the sliders.
Lock the quick release lever (B) and make
sure the bushings (A) are properly seated
in the sliders.
Fit bolt end (C) in suitable slider groove
and tighten the screw (D) to specified
torque.
WARNING: Theseslidersare spe-
cifically designed to fit this type of
hub. Do not use any hub design other than
that specified here, as this would not
ensure proper fastening of the wheel and
may lead to breakdown of the assembly
components.

Z3
QR20
3
C
ADJUSTMENT
SPRING PRELOAD
Spring preload determines COMPRES-
SION damping and is adjusted by turning
the adjustment knob (3) on the top of the
fork legs. From the factory the fork is set at
minimumpreload,i.e.theadjustmentknob
completely unscrewed counterclockwise.
However, springs are slightly preloaded
to counteract static loads. By turning the
adjustment knob clockwise, the preload is
increased up to the maximum value equal
to 15 mm spring preload. This adjustment
is essential in order to have the right fork
response for the rider’s weight and riding
style.
REBOUND ADJUSTMENT
Right slider botom is equipped with an
adjuster screw (C) for REBOUND damp-
ing.
To adjust, always start from the minimum
damping setting, i.e. with the screw fully
turned counterclockwise. Each adjusting
position can be identified by a click.
IMPORTANT: do not force the adjuster
knob (C) over its limit.

Z3
QR20
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FORK LEG OIL CHANGE
CHANGING PUMPING
ELEMENT SEALS
FOOT NUT FIG. 4
SPRING FIG. 2
DUST SEAL FIG. 6
STOP RING. 7
OIL SEAL FIG. 8
PUMPING ROD FIG. 12
REBOUND SPRING FIG. 12
VALVE ASSEMBLY
CHANGE
PILOT BUSHING AND
SEAL ASSEMBLY CHANGE
STANCHION TUBE CAP FIG. 1
FOOT BUFFER FIG. 11
CROWN AND STANCHIONS
ASSEMBLY FIG. 5
SPRING CHANGE
BOTTOM ADJUSTER FIG. 3
PUMPING ELEMENT INNER O-RING
FIG. 13
STOP RING FIG. 14
UPPER WASHER FIG. 9
PILOT BUSHING FIG. 10 VALVE ASSEMBLY FIG. 14
DISASSEMBLY
GENERAL
– The reference numbers given in this section relate to the components shown in the fork exploded view.
– Before starting any operation. please read the diagram below. It shows the quickest procedure and the exact disassembling
sequence. Locate the part you need to remove in the diagram, then look at the arrows to determine which other parts you need to
remove first.
DISASSEMBLY DIAGRAM

Z3
QR20
4
5
28
34
11
SPRING CHANGE
FIG. 1
Unscrew the caps (4) with a 21 mm
socket wrench.
Remove the caps complete with O-ring
(5) from the stanchions.
FIG. 2
Push the stanchions into the sliders and
remove the lower washer (11) and the
spring (34) from each fork leg.
Drain all oil from the fork legs.
WARNING: Rememberto always
recycle any used oil.
To change the fork leg oil follow the
procedure as described in section
“REASSEMBLY” from Fig. 27 to Fig. 29.
PILOT BUSHING AND SEAL
ASSEMBLY CHANGE
FIG. 3 (only right leg)
Turn fork legs upside down and press
adjuster retainer (28) with a small screw-
driver to release it. Remove adjuster as-
sembly (28) from the slider.

Z3
QR20
26
29
Dx.
Sx.
1
19
FIG. 4
Remove foot nuts (26) and (29) with a
socket wrench.
FIG. 5
Withdraw the crown and stanchions as-
sembly (1) from the sliders.
FIG. 6
Remove the dust seal (19) from the top of
the sliders using a small screwdriver.

Z3
QR20
20
21
A
22
FIG. 7
Remove the stop ring (20) from the sliders
byplacing the screwdriverbitin oneofthe
three openings on the stop ring.
IMPORTANT: when removing the stop
ring, make sure not to damage its seat.
FIG. 8
Fit the slider protector (A) onto the slider
and remove the oil seal (21) with the help
of a large screwdriver.
IMPORTANT: when removing the oil
seal, make sure not to damage its seat.
Once removed the oil seals should not be
used again.
FIG. 9
Remove the upper washer (22) from the
slider.

Z3
QR20
23
1825 14
1825 12
Sx.
Dx.
FIG. 10
Fit the bit of a small screwdriver into upper
edge slot of the pilot bushing (23) and lift
gently. Pull the bushing out of the slider
and make all necessary changes.
REPLACING PUMPING ELEMENT
SEALS
FIG. 11
Remove the foot buffer (18) complete
with ring (25) from the pumping rod ends
(14) and (12).
FIG. 12
Withdraw the pumping elements (14)
and (12) and the rebound spring (15)
from the stanchion tube top. Replace the
seal ring (13) if damaged or worn out.

Z3
QR20
27
14
A
33
17
16
FIG. 13 (only right leg)
Remove the stop ring (33) from pumping
element bottom (14) with a small flat
screwdriver.
Mark stop ring seat into inner rod for
proper fitting.
Use the same screwdriver to remove the
ring (A) and screw inner rod until adjuster
threaded end is disengaged from pump-
ing element.
Remove inner rod and replace O-ring
(27) if damaged.
VALVE ASSEMBLY CHANGE
FIG. 14
To check that the valve assembly is oper-
ating correctly, it is necessary to work on
the inside of the stanchion tube.
Slip off the stop ring (17) using pointed
pliers.
Pull the valve assembly (16) out of the
tube with one finger in the same sequence
as in the figure.

Z3
QR20
23
22
21
B
REASSEMBLY
CAUTION:beforereassembling,allmetal
components should be washed carefully
with inflammable, preferably biodegrad-
able, solvent and dried with compressed
air.
PILOT BUSHING AND SEAL
ASSEMBLY
FIG. 15
Check that no dirt or debris is between
sliderand bushing. Insertthepilotbushing
(23) into place so that it adheres to the
slider.
FIG. 16
Fitthe upperwasher(22) into thesliderso
that it touches the pilot bushing.
FIG. 17
Lubricate the oil seal (21) and place it
onto the seal press (B) with the hollow
side toward the slider.
Press the oil seal until it touches the lower
washer by using the above seal press.

Z3
QR20
20
19
33
14
A
27
FIG. 18
Insert the stop ring (20) into the slider
making sure it is properly seated into
place.
Use buffer (B) to properly seat the ring
into the slider.
FIG. 19
Lubricate the dust seals (19) and fit them
into the stanchions from the spring end.
PUMPING ROD ASSEMBLY
FIG. 20 (only right leg)
Lubricate the O-ring (27) and fit inner rod
threaded end into pumping element (14).
Turn inner rod clockwise so that threaded
end can be seen the into pumping element
and stop ring seat (33), marked during
disassembly.
Installez la bague de butée (33) dans le
logement sur la tige interne et la bague
(A) dans le logement sur la tige
amortisseur.

Z3
QR20
12-14
15
13
16
25
18 14
24
25
18 12
24
Dx.
Sx.
17
16
VALVE AND PUMPING ROD
ASSEMBLY
FIG. 21
After having overhauled or replaced the
valve unit and after having cleaned the
inside of the tube, reassemble. Assemble
valve components (16), in correct se-
quence.
Then fit pumping elements (12) and (14)
with seal ring (13) and rebound spring
(15) into the valve assembly (16).
FIG. 22
Lubricate the O-rings (24-25) and reas-
semble the foot buffer (18) onto pumping
element ends (14) and (12).
FIG. 23
Fit this assembly into the stanchion tube
and properly seat the valve assembly
(16).
Insert the stop ring (17).

Z3
QR20
1
19 19
26
29
Dx.
Sx.
Nm 12
28 DE
CROWN AND STANCHIONS
ASSEMBLY
FIG. 24
Fitthe crownand stanchionsassembly(1)
- with the dust seals in place - gently into
the sliders seals.
IMPORTANT: to avoid any damages to
sealing surfaces, keep the stanchions duly
lubricated and squared into the sliders.
Press the crown and stanchions assembly
fullydown andcheck thatthreaded ends of
pumpingelements(14) and (12) are com-
ing out through the bottom of the sliders.
Check to see that the stanchions slide
unrestricted by cycling the fork up and
down several times.
The tube should slide freely inside the seal
assembly without any side play. In the event
it is too hard or too soft, repeat the previous
steps described above and check compo-
nents to ensure they are not damaged.
Seat the dust seals (19) on top of the
sliders.
FIG. 25
Screw the foot nuts (26) and (29) on the
threaded elements of pumping elements
(14) and (12).
Tighten to 12 Nm.
Check to verify that the stanchions slide
properly through the stroke by pumping
them up and down several times.
FIG. 26
Fit the retainer (D) into the slider (E) to
reassemly the adjuster unit (28).

Z3
QR20
H
Travel(mm) H (mm)
100 45
110 55
130 65
34
4
5
Nm 12
HOW TO FILL WITH OIL
FIG. 27
Pour oil little by little when the stanchions
are fully down and then pump with the
crown so as to have a better filling.
Ensure proper oil level (H), from the top of
the stanchion tube, in both legs.
SPRING AND CAP
FIG. 28
Fit the springs (34) into each stanchion
tube.
FIG. 29
Lubricate the O-ring (5) on the cap (4).
Turn the preload adjuster (9)
counterclockwise until it is at its minimum
setting and install the lower washer (11).
Start the caps with the O-ring (5) in place
into the stanchion tube threads by hand.
Tighten caps (4) to 12 Nm.

Z3
QR20
A
B
SPECIFIC MARZOCCHI TOOLS
Ref. Item. Description and use
A R 5089 AB Slider protector: to remove the oil seal from the slider
B R 5090 Oil seal press: to press oil seal into the slider