I ride a 42 in front and 15 in back, hope to keep it this way. I'm about 180 lbs. Was wondering if anyoine had any reccomendations for a crankset for me - someone suggested the Shimano Sora but I have heard they are quite heavy. Which is fine, I guess, but I would prefer to keep it on the light side. Also keep in mind I'm aiming for about $100.