Nope, that would be "27 inches development". "Gear inches" refers to the nominal wheel diameter multiplied by the gear ratio. Approximately, development == gear inches * pi.
I prefer to use development as my unit, taking into account the actual circumference of the wheel and tire. Only at that point can you compare apples-to-apples among a broad range of bicycles.
I prefer to use development as my unit, taking into account the actual circumference of the wheel and tire. Only at that point can you compare apples-to-apples among a broad range of bicycles.