Abstract: An adjustable stabilizer bar (10) for a vehicle comprises a primary torsional reaction segment (12). The primary reaction segment includes an outer tube (36) selectively engaged through a splined cog (58) to a torsional bar (42). The cog (58) can be positioned to provide zero torsional stiffness by decoupling the outer tube (36) from the torsional bar (42) and it can be positioned to vary the torsional stiffness between minimum and maximum torsional stiffness positions wherein the cog engages the outer tube (36) to the torsional bar (42).