Originally Posted by urbanknight

Look harder. I have an 11-28 from SRAM. But not everyone would need both the 11 and the 27. Some people might like to coast down hills or have a personal speed limit of say 30 or 40. Those people wouldn't use an 11, so they stick with the 12. Other people like to mash up hills and not worry about cadence, so they wouldn't care for the 27/28. I like to save my knees, so I got a 28 for the major climbing rides. I also like taking a couple minutes off my commute which goes down La Tuna Canyon, so the 11 comes in handy too.