Royal Enfield SPRING FRAME O.H.V. 250cc CLIPPER 1954 Workshop Maintenance Manual page 55

ROYAL ENFIELD WORKSHOP MANUAL
1. Description of Frame
The frames used on the above models
are basically identical, with swinging arm
rear suspension, but there are some small
differences in
attachment, the method of attachment of the
pivot point for the swinging arm and in the
width between the brackets supporting the
upper ends of the rear suspension units. For
part numbers of frames see appropriate
spares lists.
The frame is built throughout of cold
drawn weldless steel tubing with brazed or
welded joints, liners being fitted where
necessary for extra strength. All the main
frame members
chromemolybdenum alloy steel tubing
which retains its strength and resistance to
fatigue after brazing or welding.
The swinging arm unit which forms the
chain stays is provided with large diameter
phosphor bronze bushes and pivots on a
stout steel tube which is secured to the main
frame by a long bolt passing through the
pivot lugs. Hardened steel thrust washers
are provided to deal with side thrust. The
torsional rigidity of the swinging arm unit
helps to maintain the rear wheel upright in
the frame and thus relieves the wheel
spindle of bending stresses to which it is
subject with other types of rear suspension.
2. Steering Head Races
The steering head races, 34085, are the
same at the top and bottom of the head lug
and are the same for all models. They are
easily removed by knocking them out with
a hammer and drift and new races can be
fitted either under a press or by means of a
hammer and a wooden drift.
3. Removal of Rear Suspension Unit
The rear suspension units are readily
removed by undoing the top pivot pin nut,
driving out the pivot pin, then hinging the
suspension unit back on the lower pivot pin,
removing the lower nut and pushing the
suspension unit off the pivot pin welded to
the fork end.
4. Servicing Rear Suspension Units
(a) Proprietary Units. The proprietary
units fitted to most 1954 and all 1955
models are sealed and servicing of the
internal mechanism can be carried out only
by the manufacturers.
Section H1 Page 2
the lugs for engine
are made of
The rubber bushes in the top and bottom
eyes can easily be renewed and the spring
can be removed by pushing down on the
top spring cover so as to release the split
collar above it. After removal of the split
collar the top cover and spring can be lifted
off. When reassembling, the spring should
be greased to prevent rust and squeaking if
it should come into contact with either of
the covers.
The standard solo springs have a rate of
100-105lb. per inch and it is not difficult to
compress these by hand. Heavier springs
having a rate of 130lb. per inch are available
which may require the use of a spring
compressor, as shown in Fig. 2.
(b) Royal Enfield Units. Mark 1.
Enfield rear suspension units, Part Number
34276 or 36451, are shown in Fig. 3. Units
having Part No. 34276 are fitted with
springs of .252 in. diameter wire (Part No.
34284) having a rating of approximately