Adjustments To Steering Head And Front Forks; Front Hub; Brake Adjustment; Brake Relining - BSA M20 Maintenance Manual And Instruction Book

Re-positioned. Insert the wheel spindle, but before
finally tightening the spindle nuts, the chain should be
finally adjusted and the wheel aligned by means of
the gauge provided in the tool kit (see page 21).

FRONT HUB

The particulars given above for the rear hub are
essentially the same for the front hub. Before the
wheel can be removed, however, the speedometer
drive cable must be disconnected at its lower end,
and also the front brake cable. After withdrawing the
wheel from the forks remove the speedometer drive
from the spindle, for which purpose, it is only
necessary to unscrew its locknut. This will expose
the bearing adjusting sleeve and locknut. When
replacing the speedometer drive unit make sure that
the tongues on the driving pinion engage with the
slots in the hub shell.

BRAKE ADJUSTMENT

The front brake is adjusted by means of the screwed
sleeve on the cable stop, fitted to the brake cover
plate.
The rear brake is adjusted by means of a wing nut on
the end of the brake rod. An adjustable stop is
provided to enable the pedal to be altered to suit the
rider's convenience.

BRAKE RELINING

After removal of the brake shoes (see "Dismantling
the Hubs", page 27) the old lining is easily taken off

ADJUSTMENTS TO STEERING HEAD AND FRONT FORKS

STEERING HEAD
In order to feel any play in the steering head the front
wheel must be clear of the ground, so that a box of
suitable dimensions should be placed under the
engine. Loosen the head yoke clip nut (just below the
handlebars) and tighten the sleeve nut on top of the
steering column until there is no perceptible shake in
the head.
Do not adjust too tightly, otherwise the ballrace will be
damaged and the steering will become stiff. Lastly,
tighten the clip nut.
If a steering damper is fitted it is necessary to remove
the knob before the adjusting sleeve is tightened.
FORK LINKS (Fig. 40)
The link bolts must be just tight enough to prevent side
play. First, slacken off the shock absorber on the lower
fork link, then release the locknuts on the offside of the
links, screw up the bolts from the nearside and
retighten the nuts.
FORK DAMPER.
This must, of course, be adjusted by the rider to suit
road conditions, and the thumb wheel can be reached
from the saddle. On earlier models, instead of the
thumb wheel, there is a large nut, for which spanner
adjustment is necessary, and consequently cannot be
by gripping the shoe in a vice, inserting a chisel
under one end and shearing the rivets off in
sequence. The rivet ends can then be punched out
of the shoe.
New linings are die-pressed to suit the curvature of
the shoes, but will require drilling and counterboring
to take rivets. Position the lining and hold it in place
at one end by means of clamps. Using the holes in
the shoe as guides, drill holes of the correct size
(5/32" dia) for the rivets adjacent to the clamp.
Turning the shoe over, counterbore the holes just
drilled, sufficiently deep so that the rivet heads will
stand below the lining surface; this is important, since
the rivets will otherwise score the brake drum.
Insert rivets into the holes and rivet them over on the
inside of the shoe. This is easily accomplished by
holding in a vice a short length of rod, whose
diameter is equal to that of the rivet head, and using
it as an anvil upon which to rest the rivet head while
hammering the shank over. This will also make sure
that the rivets do not stand proud of the lining.
Move the clamps to the next pair of holes, taking care
that the lining is kept in firm contact with the shoe the
whole time, and repeat the above procedure. When
the lining is finally riveted down, bevel of the ends of
the linings and file off any local high spots.
Precautions to be observed when fitting the relined
shoes to the hubs are given in the chapter on
"Dismantling the Hubs", page 27.
Fig. 40. Fork links and steering head.
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