TECHNOLOGY STORIES BIKE INFO, GEOMETRY ... - Vintage Trek

Inspect the parts
1. With a clean rag, wipe off
all the surfaces. If any part is
worn, it should be replaced. Signs
of wear on the pivot and link
axles are discoloration or a high
degree of polish.
Some dark deposits may be
left as the bushings and axle ‘seat
in’ to each other. When this hap-
Fig. 40
pens, some of the bearing material
is sort of plated onto the axle.
Its normal, and actually makes the pivot run smoother.
The bushings are harder to inspect; some discoloration
is normal as the bushings and axle ‘seat in’ to each other.
If wear looks uneven or non-concentric, its best to replace
them.
Note: When in doubt, throw out old parts. Its relatively
cheap to replace the parts, and time consuming to perform
a rebuild. You do the customer a favor by only tearing their
bike apart once.
Prepare the parts for reassembly
1. Clean the bonding surfaces of the main pivot bushings
and frame. These surfaces include the outside of the
tubular main pivot bushing, the seating surfaces of the main
pivot ‘top hat’ bushings that go into the swingarm, and the
parts of the frame and swingarm that the bushings contact.
These surfaces should be cleaned with Loktite Kleen ‘n
Prime.
Be careful not to get Kleen n Prime on the paint or
bushing material. It will remove paint, and also remove the
lubrication in the bushings.
2. To clean the rocker pivot bushings and upper swingarm
pivot bushings, simply wipe clean of dust or other
debris.
3. Do not lubricate any bushings.
4. Clean the pivot axle bolts, shock mount bolts, and
rocker bridge bolts with Kleen n Prime.
Install the main pivot bushings
1. Check the fit of the bushings in the frame and swingarm
by dry-assembling them (practice installation, but without
Loktite). Normally the bushings are a light press fit,
meaning they are snug but easily go into place with hand
pressure. If the parts fit correctly, go to Step 2. If they seem
very loose, go to Step 3.
2. If the parts fit correctly, apply Loktite 290 to all
contact surfaces between the bushings and the frame or
swingarm, and install the bushings.
3. If the parts seem very loose, Loktite RC680 is
required. 290 is a thread locker, and it works best where
parts are in tight contact. RC 680 is a filler, so it has the
ability to fill larger gaps and securely bond parts that do not
fit tightly together.
4. After installing the bushings, wipe off any excess
Loktite, particularly removing any Loktite that contacts the
bearing surface.
2002 Trek Technical Manual
Install the main pivot axle.
1. Carefully align the swingarm with the main pivot
of the frame. The fit is tight. Avoid contact between the
bushings and any residual Loktite. Avoid scarring of the
pivot surfaces as you slide the parts together.
2. Align the swingarm and install the main pivot axle
(the long one) from the right side of the bike. Slide it all
the way through the frame and swingarm eyes.
3. Apply Loktite 290 to the threads of the pivot bolt,
and install the bolt from the left side of the bike. Tighten to
61-75 lb in (6.9-8.5Nm).
Install the rocker bushings
1. The bushings in the rocker pivot lug and the upper
swingarm are all installed dry. Simply press them into
place, being careful to keep them aligned during insertion.
Install the rocker and pivot axle.
1. Apply Loktite 290 to the threads of the rocker bridge
bolts.
2. Loosely assembly the back of the rocker, but do not
attach the small cylindrical spacer yet. Leave the bolts 4-5
turns unthreaded.
3. Slide the rocker around the seat tube. Install the
cylindrical spacer and remaining rocker bridge bolts.
4. Insert the rocker axle from the right side of the
bike.
5. Apply Loktite 290 to the threads of the rocker pivot
bolt, and install the bolt from the left side of the bike.
Tighten to 50-75 lb in (5.7-8.5 Nm).
6. Tighten the rocker bridge bolts to 50-85 lb in
(5.7-9.6 Nm).
Install the rocker and pivot axle.
1. This axle goes through the swingarm, and rocker.
Apply Loktite 290 to the threads of the pivot bolt, and
install the axle from the right side of the bike. Tighten the
axle bolt to 50-85 lb in (5.7-9.6 Nm).
Install the shock mount bolt.
1. Make sure the shock orientation is how you would
like it. Insert the upper shock mount bolt from the right
side of the bike.
2. Insert the lower shock mount bolt from the right
side of the bike.
2. Apply Loktite 290 to the threads of the bolts. Install
the nuts and tighten to 133-164 lb in (15-18.5 Nm).
Allow to Dry
Loktite normally requires 24 hours to completely set.
During this time, the bike should not be ridden. Do not
compress the suspension or in other ways disturb the
Loktite until is has fully set.
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