The rule of thumb is usually a 2 tooth difference. That should be enough to get you up a hill or home thru a headwind. For more you might need additional chain which is possible thru the use of quick disconnect links like the wipperman or the sram.
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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