I'm sure it's similar to the periodic massive shortages in the firearms industry. In the face a huge shortages, companies focus all their production towards their highest priority items. Everything else waits because they can't afford to keep shutting down production lines to make lower priority items. When the high priority stuff catches up they start back to making other stuff again.i really don't get it. factories should have been open for months but you can't find a 10-51 xtr cassette to save your life right now. MANY frames are also unavailable.