Many years ago, I have lost valuable data stored on Sony QIC magnetic tapes (QIC = quarter-inch cartridge), because those magnetic tape cartridges contained a r

Many years ago, I have lost valuable data stored on Sony QIC magnetic tapes (QIC = quarter-inch cartridge), because those magnetic tape cartridges contained a rubber belt that was used to move the magnetic tape inside the cartridges, when they were inserted in a tape drive. After many years of storage, the rubber belts had become fragile and any attempt to move the magnetic tape turned the belts into dust, making the cartridge unreadable. The LTO magnetic tape cartridges used today are much more robust, because the cartridge is simpler and it hopefully no longer includes any parts that are susceptible to rapid aging. At that time, i.e. 30-40 years ago, rubber belts were used because they ensured in a simple mechanical way a constant moving speed for the magnetic tape. Later, the electronic alternatives for ensuring a constant tape speed by varying the speed of an electric motor have become cheap enough to eliminate the need for such belts.