The cause of poor loading performance from the +2 range of Spectrums is often due to stretching and wear of the tape mechanism drive belt.
The old belts perished over time, particularly when stood unused for many years when they would often develop a "kink" where the belt rested unmoved over the capstan. This kink becomes a permanent feature in the belt causing it to jump when the drive is used again.
This square section belts is of identical size to the original but made from modern, more resilient materials.
This is a replacement for the SMALL belt on the two belt Spectrum +2 grey models.