I got a set of Campagnolo Strada cranks with a 42 ring and a 52 ring. The 42 cannot be run by itself because the 42 bolts to the 52. If I want to use it on a fixed gear what do I need to just run the 42? Or is there another front back teeth ratio / combo that would work with this? or on other words how can I run this crank on a SS/FG? Thanks