Sonex Wheel and Brake Assembly and Installation Instructions - Manual (Page 2)

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2
Wheel and Brake Assembly and Installation
Instruction No. SNX-L01-01
Page 2 of 2
Assembling the Wheels
After the wheels and brake drum have been prepared the
wheels can be assembled with the tires and tubes.
Assembly Tips:
a. Dust the inside of the tire and the outside of the tube with
baby powder.
b. Install the wheel assembly bolts with the heads against the
brake drums and the nuts on the outside of the wheel.
c. Before tightening the bolts, make sure the axle bore is in
proper alignment. If a "step" is noted between the wheel
halves, adjust the alignment of the wheel halves and/or
redrill the bolt holes so proper alignment can be achieved.
d. Slightly infl ate the inner tube and then release the air.
This helps get twists out of the tube before they become
creases which may lead to tube failure.
e. Infl ate the tubes to approximately 50 psi. 30 psi provides
a bit more "cushion" but increases rolling drag and may
cause a pinched tube if fl ying off a hard surface runway.
nched tu nched tu
f. Grease and install the wheel bearings. Use a high-quality
bearing grease. Do not use white lithium grease.
Brake Cam Modifi cation
This simple modifi cation provides smoother brake application.
Warning. Always wear safety glasse
Warning. Always wear saf Warning. Always wear saf s when working on the
brake shoes and backing plates. The shoes are held in place
with spring tension.
1. Remove the brake pads from the backing plate
2. Remove the brake actuating cam from the backing plate.
3. Round all four corners of the cam with a fi le. Be sure to
round all corners uniformly.
When the wheel is slid onto
the axle, the brake drum will
not cover the brake backing
not not
plate. The brake drum will
cover the brake shoes, leaving
a space between the backing
plate and the brake drum.
Installing the Brake Backing Plate
Smooth brake operation depends on the brake backing plate
being mounted perpendicular to the axle. This is easy to check
by placing a small draftsman's triangle against the axle in the
12:00 and 3:00 O'clock positions, and the striking the backing
plate with a mallet to square it to the axle.
Installing the Wheels on the Axles
4. Re-install the actuating cam.
5. Lightly grease the lobes of the cam and re-install the
brake shoes.
Round the cam lobes to achieve smooth brake application. ake ap ake ap
The axle nut should be tightened against the wheel snuggly
to seat the bearings, and then backed off until the wheel turns
freely, but without any sign of looseness on the axle.
Drill a 5/32" diameter hole through the axle for an axle-nut
cotter pin.
The brake drums are not
supposed to cover the brake
backing plate.