Steve (Rex) used to have an option for a carbon rear end. This appears to be one of those. They may have had a multiangle option so he could customize the rear triangle. That is a nice looking Rex but an older one, and the Tiagra rear mech is a little surprising.
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I'm not one for fawning over bicycles, but I do believe that our bikes communicate with us, and what this bike is saying is, "You're an idiot." BikeSnobNYC