ROYAL ENFIELD 350cc O.H.V. WORKSHOP MANUAL
Page 25
44. Cush Drive Rubbers.
The condition of the cush drive rubbers in the
rear wheel can be gauged by placing the machine on
the rear stand, applying the rear brake and trying to
turn the wheel by pulling on the tyre or rim. If there is
more than one inch free movement of the tyre
(half-inch if machine is to be used across country),
the rubbers should be examined. Access to the
rubbers is obtained by removing the wheel and the
brake cover plate, then unscrewing the three
Simmonds nuts at the back of the brake drum and
knocking out the three shouldered pins which secure
the cush drive lock ring, after which the combined
sprocket and brake drum can be lifted off the hub
barrel thus exposing the six rubber blocks. After
fitting new blocks before replacing the sprocket,
smear some grease on the protruding end of the hub
barrel and also on the back surface of the cush drive
lock ring. The sprocket will enter the spaces between
the rubber blocks more readily if the latter are dusted
liberally with French chalk or smeared with soft
soap. With this type of cush drive it will probably be
found best to lie the blocks flat in the hub shell, not
to tilt them as is recommended for the smaller cush
drive fitted to the Royal Enfield Side-valve Model
WD/C.
FRAME AND FORK
45. Alignment of Wheels.
The only way to make sure that the wheels are in
alignment is to check one against the other. Frames
and forks are set when built so as to ensure that the
centre of the two wheel spindles, the centre line of
the engine attachment lugs and the head lug, all lie in
the same plane. Individual points along the frame
tubes, however, are not checked and the wheel
cannot, therefore, be accurately lined up by ensuring
that it is central between the chainstays or backstays.
Neither can it be assumed that the wheel will be in
line when it is pushed hard against the front end of
the slots in the rear fork ends.
Wheel alignment can be checked by using a
straightedge if one is available. Wooden straight
edges, however, are liable to warp and are, therefore,
not reliable. The best way to check the alignment of
the wheels is to use a piece of fine string. This should
be tied to one spoke of the rear wheel, taken round
the tyre, brought towards the front of the machine and
pulled taut with the front end some inches away from
the front wheel. The string should then be brought
slowly in towards the front wheel, keeping it taut and
watching carefully to see when it touches the front
portion of the rear tyre. It should just come on to the
rear tyre at two points simultaneously with touching
the front tyre at two points, assuming that the front
wheel is pointing straight ahead. Check the setting by
testing with string in the same way along the other
side of the machine.
The above method checks only the alignment of
the lower portions of the two wheels. If the frame is
twisted or the forks are bent, it is possible that the
lower portion of the wheels will be in alignment
while the upper portion is not. Any serious twist can
be seen by looking along the machine to make sure
that both wheels lie in the same plane. In case of
doubt this can be checked by using the string near the
top of the wheels, after removal of the mudguards,
battery, toolboxes and engine cylinder.
If the wheels are in alignment and the frame is
not twisted or bent the rear chain should also be in
alignment. This can be checked by looking along it
with the chainguard removed. If the chain has been
run out of alignment it will show definite indications
on the sides of the sprocket teeth and on the inner
faces of the chain links. If the wheels cannot be lined
up without throwing the chain out of alignment, the
probable cause is that the rear frame portion is bent.
46. Adjustment of Fork Links.
Side play on the front fork swivel pins should be
eliminated as far as possible without interfering with
the free movement of the forks. The two bottom fork
spindles have right- and left-hand threads and screw
into the bottom links. To adjust these, first remove
the shock absorber hand nuts and star washers, taking
care not to lose the small springs and plungers inside
the hand nuts (see Fig. 39). Then loosen the locknuts
on the fork spindles. The nuts on the right-hand side
of the machine have left-hand threads. Adjust the
links by turning the spindles by means of the squares
on their ends in a clockwise direction (viewed from
the left-hand side of the machine) to give more side
clearance or in an anti-clockwise direction to take up
clearance.
The two top spindles have threads only on the
left-hand side of the machine. To adjust these, loosen
the locknuts and turn the spindles by means of their
hexagon heads in a clockwise direction (viewed from
the right-hand side of the machine) to take up
clearance or anti-clockwise to give more clearance.
Check the adjustment after tightening the locknuts
and make sure that the forks work perfectly freely. A
little side play is preferable to excessive friction. Any
necessary damping action is provided by the
hand-operated shock absorbers which must be
replaced after adjusting the fork swivel pins. Note
that the adjusting nut on the right-hand side of the
machine has a left-hand thread, and that both
adjusting nuts are tightened by turning their tops
towards the rider when in the saddle.
Very little damping action is required for
main road work and the adjustment of the shock
absorbers should be left so that it is easy to move
the star washers with the thumb.
47. Worn Swivel Pins or Bushes.
If excessive up and down play is present in any
of the swivel pins the pin and/or bush should be
renewed. All four swivel pins work in renewable
bronze bushes housed in the forks, steering stem or
ball head clip. To remove the two lower swivel pins,
first unscrew the shock absorber hand adjuster knobs
and star washers, then the locknuts and turn each
swivel pin in turn in a clockwise direction (when
viewed from the left-hand side of the machine) until
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