BSA D14/4 BANTAM SUPREME D14/4 BANTAM SPORTS, Руководство по ремонту

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D14/4 FRONT FORKS E8
The repair will be simplified and be very much
better if a suitable press is available to the repairer.
Having checked the tubes for straightness and reset
as necessary, a check can now be made of the top and
bottom yokes. First, assemble both tubes into the
bottom yoke so that a straight edge laid across the
lower end touches all four edges of the tubes then,
tighten the pinch bolts. Now view them from the side;
both tubes should be quite parallel. Alternatively, the
lower 12" of the tubes can be placed on to a surface
plate, when there should be no rocking. Having
checked the tubes this way, check the gap between
them on the ground portion.
If the tubes are not parallel, as in Fig. E8, then the
yoke must be reset, providing the error is not
excessive.
To reset, hold one tube in a vice on the unground
portion (using soft clamps) and reposition the other
tube using a longer and larger diameter tube to obtain
sufficient leverage.
The next step is to place the top yoke in position
over the tubes, when it will be seen if the steering
column is central. Figure E9, shows a bent column.
Finally, check that the tubes remain parallel when
assembled into the top yoke only. In this case the
bottom yoke can be fitted loosely on the tubes, acting
as a pilot only.
Though it is possible to rectify slight errors in
alignment by resetting, it is much safer to renew the
part affected, especially when the malalignment is
excessive.
ADJUSTING STEERING HEAD RACES
It is most important that the steering is always
correctly adjusted and a check should be made in the
following way.
Place a strong support under the engine so that the
front wheel is raised clear of the ground then, standing
in front of the wheel, attempt to push the lower fork
legs backwards and forwards. Should any play be
detected, it will be necessary to adjust the steering
head races. It may not be possible to distinguish
between play in the head races and play in the fork leg
bushes, though in some cases there may be both. If
possible, ask a friend to place the fingers of one hand
lightly around the top head races whilst the forks are
being pushed and pulled. Any play will be felt quite
easily by the fingers.
To adjust the steering head races, slacken the clip
bolt on each fork leg below the headlamp to enable the
bottom yoke to take up a new position. Release the
steering head clip bolt and tighten down the adjuster
nut until the slackness has been eliminated. Avoid
over-tightening the adjuster or the ball bearings will
become indented into the races, making the steering
extremely difficult and dangerous.
When the correct adjustment has been made,
retighten the steering head clip bolt and finally, the
fork leg bolts in the bottom yoke.
To check the setting, hold the handlebars lightly and
move them round slowly, when the steering should be
free and rotate smoothly.
If the movement feels "lumpy", indicating damaged
races, the ball bearings, cups and cones must be
removed for examination as described in the following
section, and be replaced as necessary.
RENEWING STEERING HEAD RACES
If the only attention required is the examination or
replacement of the steering head races, it will not be
necessary to dismantle the forks completely. However,
if sufficient slack can be obtained in the headlamp
cable harness to allow the forks to be drawn away
from the frame, then the harness must be detached as
detailed in the section dealing with headlamp removal
on page D10.