I did my best to keep replacing chains, not cassettes, but after about 6000 miles on my Vado 4 in a little over a year, the cassette really needed to be replaced. Went to my LBS a couple of weeks ago to set up an appointment. Not only were no Shimano cassettes in stock with the original gearing (10 speed, 11-42) with their suppliers, they weren't even showing back orders as an option. The LBS basically left it up to me to find the cassette. I searched far and wide. I found some off brand cassettes. I think Performance Bike said they'd be available in late July. Finally after a week of looking, for a few minutes, Jenson USA had 3 - Shimano 10 speed 11-42 cassettes. I was able to nab one. It will be here next week. Crazy times!!