RevoKnuckle is a front suspension layout based on the MacPherson strut, developed by Ford for the 2008 Focus RS.

In a conventional MacPherson strut (above right) the steering axis (around which the wheel moves when the steering wheel is turned) is along a line from the mounting point of the strut at the top to the ball joint at the bottom (light blue).

In the RevoKnuckle system (above left) the bottom end of the strut is C-shaped and the arms of the C locate a steering knuckle (yellow), which can turn to steer the wheel. The pivot points of the knuckle determine the steering axis. Because they are closer to the wheel centre line, the king-pin inclination and steering offset are reduced.

In practice, a vehicle with the RevoKnuckle system has several advantages:

• torque steer is reduced
• brake judder is reduced
• steering nibble (vibration) is reduced
• the steering is less sensitive to tyre wear

Other advantages of the RevoKnuckle system are:

• lower cost than a double wishbone suspension
• lighter weight than a double wishbone suspension
• simple packaging, as the system fits into the same space as a MacPherson strut