speedbar-frame-plist

speedbar-frame-plist is a variable defined in `speedbar.el'.
Its value is

(minibuffer nil width 20 border-width 0 internal-border-width 0 unsplittable t default-toolbar-visible-p nil has-modeline-p nil menubar-visible-p nil default-gutter-visible-p nil)

Documentation:
Parameters to use when creating the speedbar frame in XEmacs.
Parameters not listed here which will be added automatically are
`height' which will be initialized to the height of the frame speedbar
is attached to.

You can customize this variable.