How is the nominal length of a conventional V-belt determined?

The nominal length of a conventional V-belt is determined by measuring the inside length of the belt. This measurement is critical because it directly corresponds to the belt's fit around the pulleys, ensuring proper tension and alignment when installed in a drive system.

Using the inside length allows for the calculation of how the belt engages with the pulleys, which is essential for the effective transmission of power. If the belt were measured by its outside length, width, or thickness, it would not provide an accurate representation of how it operates within the system. The dynamics of belt engagement with the pulleys necessitate that the inside length is the standard measurement for determining the correct belt size.