Recently purchased a CAAD 9 with a Shimano Tiagra triple crankset (50/39/30) installed on the bike. I would like to put a compact crankset on in it's place because I don't use the 30 on the triple. I was wanting to put a 50/34 on and was unsure of which company and what specific specs. I need to look for. I'm relatively new to the road bike scene and am looking for some input. Thanks.