Bicycle wheel to counteract the leading spokes. When forward torque is applied (i.e., during acceleration ), the trailing spokes experience a higher tension, while leading spokes are relieved, thus forcing the rim to rotate. While braking, leading spokes tighten and trailing spokes are relieved. The wheel can thus transfer the hub torque in either direction with the least amount of change in spoke tension, allowing the wheel to stay true while torque is applied. Wheels that are not required to transfer any significant amount of torque from the hub to the rim are often laced radially. Here, the spokes leave the hub
Counting rods ancient counting rods, and further explanation, you can visit the sites Counting rods Counting rods () are small bars, typically 3–14 cm long, that were used by mathematicians for calculation in ancient East Asia. They are placed either horizontally or vertically to represent any integer or rational number. The written forms based on them are called rod numerals. They are a true positional numeral system with digits for 1–9 and a blank for 0, from the Warring states period (circa 475 BCE) to the 16th century. Chinese arithmeticians used counting rods well over two thousand years ago. In 1954 forty-odd