Marzocchi MARATHON User manual

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INSTRUCTIONS
GENERAL RULES
1. Where specified, assemble and disas-
semble the shock absorption system us-
ing the M ARZOCCHI special tools only.
2. On reassembling the suspension system,
always use new seals.
3. Clean all metal parts with a special,
preferably biodegradable solvent, such
as trichloroethane or trichloroethylene.
4. Before reassembling, lubricate all parts
in contact with each other using silicone
fat spray or a specific oil for seals.
5. Always grease the lip seal rings before
reassembling.
6. Use wrenches with metric size only.
Wrenches with inch size might damage
the fastening devices even when their
size is similar to that of the wrenches in
metric size.

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FAILURES, CAUSES AND REMEDIES
This paragraph reports some failures that may occur when using the fork. It also indicates possible causes and suggests a remedy. Always
refer to this table before doing any repair work.
FAILURES CAUSES REMEDIES
Oil leaking through the top of the slider 1. Oil seal is worn out
2. Stanchion tube is scored
3. Excessive dirt on slider oil seal
1. Replace oil seal
2. Replace crown/stanchions assembly, oil
seals and dust seals
3. Clean the oil seal seat and replace oil
seal and dust seal
Oil leaking through the bottom of slider O-ring seal on the cartridge nut is damaged Replace the O-ring
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
Pressure drop Cap valve damaged Replace cap and/or valve
Excessive play of stanchions in the sliders Pilot bushings worn out Replace bushings
Fork rebounds too fast in any adjuster
position
1.Dirt inside fork legs
2. RH stanchion cartridge is damaged
3. LH stanchion cartridge is faulty
1.Clean carefully and change oil
2. Replace RH stanchion cartridge
3. Check LH stanchion cartridge
Adjuster position does not affect fork
operation
1.Dirt inside legs
2. Check cartridges operation
1.Clean carefully and change oil
2. Replace and/or overhaul cartridges

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RECOMMENDATIONS FOR
MAINTENANCE
M ARZOCCHI forks are based on advanced
technology, supported by year-long experi-
ence in the field of professional mountain
biking. In order to achieve best results, we
recommend to check and clean the area
below the dust seal and the stanchion tube
after each use and lubricate 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 adjustments.
This running-in period will make fork life
longer and ensure fork top performance
over time.
IMPORTANT: change oil at least every
100 working hours and check pressure at
least every 10 working hours.
Polished forks should be cleaned with
bodywork polish at regular intervals in
order to preserve their original finish.
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 headset
manufacturer’s instructions. Improper in-
stallation 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.
DISC BRAKE SYSTEM ASSEMBLY
WARNING: if a disc brake system
is installed on Marathon 29" forks
featuring sliders glued to the arch, it is
absolutely forbidden to remove the original
bolts (ref. B). In case of a Marathon S fork
it is allowed since arch-slider monolith is
molded.
For Marathon 29”, apart from retaining
cantilever or linear pull brakes, they also
secure the sliders legs to the slider monolith.
If needed, the brake boss bolts can be
replaced with buttonhead bolts (ref. A,
part #532979QF).
Tighten the above-mentioned bolts to 10
Nm.
IMPORTANT: the bolt threads (ref. A)
are treated to ensure a hydraulic seal.
Never reuse the bolts once they 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.

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D32
D
D1
C
C
D
21
28
D
D1
CC
28
1 3
2
ADJUSTMENTS
FORK LEG PRESSURIZATION
Pump air through the valves to set COM-
PRESSION damping, as indicated in the
figure. To change the pressure inside the
fork legs, remove the protection cap (32)
(LH fork leg), remove plug (21), turn knob
(28) until you can see the valve under it (RH
fork leg). Depressurize each leg by pushing
lightly on valve pin. Fully tighten adapter
fitting (D) supplied with the fork, on a
M ARZOCCHI pump (C). Screw fitting end –
with O-ring (D1) on valve, and pressurize
until the required value is reached. Un-
screw the fitting/pump assembly and refit
the cap (32).
IMPORTANT: inflate using the special
M ARZOCCHI pump with the proper pressure
gauge. Use of improper tools or other
procedures than specified ones might lead
to improper inflating.
NOTE: in case of air leakages when adapter
fitting (D) is fitted, ensure that the O-ring
(D1) is not damaged.
REBOUND ADJUSTMENT
(r.h. fork leg)
The right fork leg is equipped with an
Extension Control Cartridge adjuster knob
(28) for REBOUND damping up to max.
rebound damping - “Lock Out”. Turning this
adjuster into the cartridge rod, changes the
hydraulic setting of the inner valves.
You can have three adjustments:
Pos. 1: “Lock Out”
Turn the knob completely counter-clockwise
to obtain full ECC lockdown (maximum
rebound damping) for steep climbs and
road riding.
Pos. 2: “Intermediate rebound
damping”
Turn the knob clockwise until hearing the
first click. This mediuam position offers slow
rebound damping for fast starts and rough
climbs.

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D
32
D
D1
C
C
Pos. 3: “Minimum rebound
damping”
Turn the knob completely clockwise until
hearing the last click. In this position the fork
will have fast rebound damping for
downhilling.
IMPORTANT: do not force the adjuster
knob (28) past its limit.
NEGATIVE AIR CARTRIDGE ADJUST-
MENT (LH fork leg –valve is
located in the center of the cap)
Pump air into the valve, as indicated, to set
COMPRESSION damping. To change the
pressure inside the fork legs, remove the
protection cap (32) (LH fork leg) and
depressurize the leg by pushing lightly on
valve pin. Fully tighten adapter fitting (D),
supplied with the fork, on M ARZOCCHI pump
(C). Screw fitting end –with O-ring (D1) on
valve, and pressurize until the required
value is reached. The higher the pressure in
the LH cartridge, the more sensitive the fork
will be and vice versa.
Unscrew the fitting/pump assembly and
refit the cap (32).
IMPORTANT: inflate using the special
M ARZOCCHI pump with the proper
pressure gauge. Use of improper tools or
other procedures than specified ones
might lead to improper inflating.
NOTE: in case of air leakage when adapter
fitting (D) is installed, be sure that the O-
ring (D1) is not damaged.
28
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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
FORK OIL CHANGE
STANCHION TUBE CAP FIG. 1/2/3/4
AIR VALVE CHANGE
FIG. 15
FOOT NUT FIG. 6
PILOT BUSHING AND SEAL ASSEMBLY CHANGE
CARWON AND STANCHIONS ASSEMBLY FIG. 9
DUST SEAL FIG. 10
STOP RING FIG. 11
OIL SEAL FIG. 12
UPPER WASHER FIG. 13
PILOT BUSHING FIG. 14
AIR-OPERATED CARTRIDGE FIG. 8
HYDRAULIC CARTRIDGE FIG. 7
AIR-OPERATED CARTRIDGE
CHANGE (left leg)
HYDRAULIC CARTRIDGE CHANGE
(right leg)
AIR-OPERATED CARTRIDGE
OVERHAUL FIG 16/17/18

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29 28 32
30
33
24
24
26
27 25
REMOVING UPPER CAP
FIG. 1
(r.h. fork leg)
Undo screw (29) with an Allen wrench and
remove knob (28).
(l.h. fork leg)
Completely undo knob (32).
Depressurize each fork leg (see section
ADJUSTMENT).
FIG. 2 (only right leg)
Remove the RH cartridge circlip (27) with
a small screwdriver.
Remove and keep the pin (26) and counter
spring (25).
WARNING: never use the fork with-
out this component otherwise the
hydraulic cartridge fitted to the slider bot-
tom might slide out from the top cap and
release the arch-slider monolith.
FIG. 3
Unscrew the caps (30) and (33) complete
with O-ring (24) with a 21-mm socket
wrench.
Remove the cap (30) from the right stan-
chion and from the hydraulic cartridge rod
(5).

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33
16
23 3
2
1
FIG. 4 (only left leg)
Lock the rod (16) and remove the cap (33)
from hydraulic cartridge end (22).
If this operation proves difficult, vice the rod
with jaws (E) (see Fig. 28).
FIG. 5
Push the stanchions (23) into the sliders (3)
and let all the oil drain out from the fork legs.
Pump the stanchions several times to help
oil drain off.
WARNING: dispose of exhausted
oil in compliance with current laws.
To change the fork leg oil follow the proce-
dure as described in section “REASSEMBLY”
from Fig. 29 to Fig. 33.
REMOVING CARTRIDGES
FIG. 6
Turn the fork leg upside-down and unscrew
the foot nuts (2) by the use of a 15 mm
socket wrench complete with O-Rings (1).

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5
22
23
3
FIG. 7 (only right leg)
Pull the hydraulic cartridge (5) out of the
R.H. stanchion tube.
Replace the whole hydraulic cartridge.
FIG. 8 (only left leg)
Pull the air-operated cartridge (22) out of
the L.H. stanchion tube.
Replace the whole cartridge or overhaul as
described in next paragraph.
FIG. 9
Withdraw the crown and stanchions as-
sembly (23) from the sliders (3).

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10 9
8
A
REMOVING GUIDE BUSHING
AND SEAL ASSEMBLY
FIG. 10
Remove the dust seal (10) from the top of
the sliders using a small screwdriver.
FIG. 11
Remove the stop ring (9) from the sliders by
placing the screwdriver bit in one of the
three openings on the stop ring.
IMPORTANT: when removing the stop
ring, make sure not to damage slider inner
seat.
FIG. 12
Fit the slider protector (A) onto the slider
and remove the oil seal (8) with the help of
a large screwdriver.
IMPORTANT: when removing the oil seal,
make sure not to damage slider inner seat.
Once removed the oil seals should not be
used again.