Originally Posted by redlude97

I don't think you understood what i meant. Not redundancy in gears but redundancy in products offered. if 53x13 is the biggest gear you need, then that is very easy to achieve with a 50T ring instead. Why is there a need for a 53 in that case? Like I said 50/36 12x25 or 12x23 covers the same range with essentially the same steps as your proposed 53/39 13-26. So what does shimano have to gain by adding those other cassettes?