Tension Adjustment
Remove plastic cover (if fitted) to locate
tension lugs. The tension lugs have a slot and
are located in the cassette on a 'bayonet'
principle. Insert screwdriver into slot (ensure a
good fit), turn lug clockwise to allow the
spring tension to push the lugs just free of the
cassette. Keep fingers away from screwdriver
tip to avoid accidental injury. Spring can now
have more or less tension applied as required.
If in doubt of tension to be applied, release
all tension and re-start. In which case, with
blind fully wound on the roller, apply 12
revolutions of lug (factory setting).
Refitting is a reversal of removal procedure
Hope this helps