>>/94675/
I ride 54/40 but if I did road racing I would go 1x with 56 or 58 for that, even on the hilly courses I've raced I found that my speed never dropped below 20 km/h and 1x 58 still covers that. 
 >>/94676/
not anymore everything current gen is at least 28t and for shimano there's nothing smaller than 30t