This article is from the Hanggliding and Paragliding FAQ, by Joao Geada with numerous contributions by others.
The control bar front and back cables must be altered or replaced to
so that the base tube is swung back 12-16 inches (30-40 cm.) from the
prone position. On gliders with loose side wires the side cables need
not be altered. On other gliders the side cables may be altered
(usually slightly longer) or a longer base tube may be used.