Spring buffer

fig. a: baseline
spring buffer
fig. b: spring buffer

The spring buffer gives one a good impression of the bouncing capability of pigtails. It is defined as the difference between pigtail length (i.e. the baseline length) and the vertical distance between the highest and lowest point on the midline. In other words, the spring buffer is the extra length the pigtail would be if fully stretched.

low buffer (low offset)
fig. c: low buffer (low offset)
high buffer (high offset)
fig. d: high buffer (high offset)

The spring buffer value is directly related to the pigtail offset; high spring buffer values require high offset values. Although offset is the most important contributing factor, hair curliness also leads to a higher spring buffer.