Section J2 - Royal Enfield SPRING FRAME O.H.V. 250cc CLIPPER 1954 Workshop Maintenance Manual

ROYAL ENFIELD WORKSHOP MANUAL
With Casquette and Steel Bottom Tubes
Used on " 250 Clipper " 1954 onwards
1. Description
The telescopic fork consists of two legs each
of which comprises a main tube of chrome
molybdenum alloy steel tubing which is screwed
into the Casquette fork head at the upper end and
securely clamped to the fork crown. Fitted over
the lower end of the main tube is the bottom tube
made of steel tubing with a forged steel fork end
flashwelded to it. Fitted on the lower end of the
main tube is a bronze bush which is a close fit in
the bore of the bottom tube. The upper end of the
bottom tube carries a bronze bush which is a
close fit over the outside diameter of the main
tube. The bush is secured to the bottom tube by
means of a gland nut with an oil seal fitted inside
it. A stud, known as the "spring stud," is fitted in
the lower end of the bottom tube and a valve port
is secured to the lower end of the main tube. As
the fork operates oil is forced through the annular
space between the bore of the valve port and the
outside diameter of the spring stud which is
formed with a double taper. Thus hydraulic
damping is provided which is light at the normal
position of the fork and becomes increasingly
effective towards each end of the fork's travel. A
compression spring is fitted inside the main tube
between the upper end of the tube and a scroll
secured to the upper end of the spring stud. The
lower end of the main tube and upper end of the
bottom tube are protected by a cover tube
screwed to the fork crown.
The fork is filled with a light oil (S.A.E. 20)
up to a level above the valve port, this oil
providing both the damping medium and the
lubricant for the bearings.
2. Dismantling Fork to Replace Spring, Oil
Seal or Bearing Bushes
Place the machine on the stand, disconnect
the front brake control and remove the front
wheel and mudguard complete with stays.
Unscrew the oil level plug after placing a tray to
catch any oil which may run out. Undo the nut
which secures the spring stud to the fork end and
knock the spring stud upwards into the fork with

SECTION J2

Front Fork
Section J2 Page 1