Here's a little industry secret: groups aren't really a thing, or at least not something Shimano provides for us. This isn't the old days where every racing bike was made the same way and could take the same parts. A group is an abstract marketing notion only, and if you want you should absolutely mix-and match parts if they'll work together. Don't feel beholden to Shimano's marketing department.

If you see someone selling a group, the retailer got it part-by-part from Shimano North America and assembled it themselves. So, the groups we provide here are our interpretation of the best mix of parts, which will work with the components or frames we often use. They're a convenient way to make sure you have all the parts and that they'll work together perfectly.