Bicycle wheel other exotic spoke lacing patterns (such as "crow's foot", which is essentially a mix of radial and tangential lacing) as well as innovative hub geometries. Most of these designs take advantage of new high-strength materials or manufacturing methods to improve wheel performance. As with any structure, however, practical usefulness is not always agreed, and often nonstandard wheel designs may be opted for solely aesthetic reasons. There are three aspects of wheel geometry which must be brought into adjustment in order to true a wheel. "Lateral truing" refers to elimination of local deviations of the rim to the left or right
Reaction wheel temporary changes in its speed result in small changes in angle. The wheels therefore permit very precise changes in a spacecraft's attitude. For this reason, reaction wheels are often used to aim spacecraft carrying cameras or telescopes. Over time, reaction wheels may build up enough stored momentum to exceed the maximum speed of the wheel, called saturation, which will need to be cancelled. Designers therefore supplement reaction wheel systems with other attitude control mechanisms. In the presence of a magnetic field (as in low Earth orbit), a spacecraft can employ magnetorquers (better known as torque rods) to transfer angular momentum