Originally Posted by HillRider

50/42 is an odd chainring combination and doesn't come OEM on any crank I know of so I doubt the combination is phased together. What I would worry about is will the front derailleur inner cage plate clear the 42T ring if it's height above the 50T ring is correct. Many front derailleurs have a minimum tooth difference requirement and it's often 10 teeth minimum so a 50/42 doesn't meet it. It can be made to work only if the front derailleur is set too high above the 50t for optimum shifting.