SRAM has a twelve-speed cassette now. Are there downsides to this? Is the chain thinner and weaker, more likely to break? Is shifting more tetchy? Is it better, some ways? I have a personal agenda, I'm shopping for a fat bike, and a lot of them have single chainrings and 11-speed cassettes, I'm wondering if they're going to end up with twelve speeds. I like wider gears, it's cool, but do I need 12 speeds to get there? Why not just make a wider cassette with eleven speeds, or ten, even.