Ladders and ladder bracing

A ladder comprising:

• a pair of inner rails and a pair of outer rails, the pair of inner rails being slidably disposed in the pair of outer rails, wherein a rear surface of each outer rail of the pair of outer rails lies in a common plane,
• a first plurality of rungs coupled between the pair of inner rails,
• a second plurality of rungs coupled between the pair of outer rails,
• a cross-brace extending between the pair of outer rails and directly coupled to the rear surface of each outer rail of the pair of outer rails, the cross-brace including:
• an end surface spaced away from the common plane;
• and
• a ramped surface having a distal portion immediately adjacent the end surface, a proximal portion immediately adjacent the common plane, and a convex transition portion extending from the distal portion to the proximal portion;
• wherein the pair of inner rails is configured to engage with the ramped surface in response to sliding the pair of inner rails within the pair of outer rails.

A ladder comprising:

• a pair of inner rails;
• and
• a pair of outer rails, the pair of inner rails being slidably disposed in the pair of outer rails, wherein a rear surface of each outer rail of the pair of outer rails lies in a common plane,
• a first plurality of rungs coupled between the pair of inner rails,
• at least one brace extending between the pair of outer rails and directly coupled to the rear surface of each outer rail of the pair of outer rails, the at least one brace including:
• a ramped surface, the ramped surface having a cross-sectional geometry including an upper portion spaced away from the common plane, a lower portion immediately adjacent the common plane, and a curved transition portion extending from the upper portion to the lower portion;
• wherein:
• the cross-sectional geometry includes four linear sides;
• the ramped surface is bounded between two of the four linear sides;
• an upper most surface of the cross-sectional geometry is a first linear side bounding the ramped surface at the upper portion;
• and
• a contact surface contacting the rear surface of each outer rail of the pair of outer rails forms a second linear side bounding the ramped surface at the lower portion.