Opel Automobile Owner's Manual page 58

58 Storage
Remove the pedal crank mounts from
the pedal crank recesses.
Adapting the rear carrier system
to a bicycle
With the rotary lever on the pedal
crank recess, roughly adapt the
adjustable pedal crank unit to the
protrusion of the pedal crank.
If the bicycle has straight pedal
cranks, unscrew the pedal crank unit
completely (position 5).
If the bicycle has curved pedal
cranks, screw in the pedal crank unit
all the way (position 1).