Thank you, Janiejones and Capwater for your reply.
I'm glad to hear that Cannondale has a good reputation, as I will not be in a position to purchase an entirely new bike any time soon -- college student.
Janiejones: I believe the bike is equipped with Shimano Sora, however, I am not one hundred percent positive; I did a Google image search on both Sora and Tiagra, and Sora looks identical to what my bike has.
When I first bought the bike, the STI (Sora?) gears did not work. I did some research and, for the most part, fixed the problem myself; however, the gears still sound rough, there is still quite a bit of slack in the brake handle/shifter, and I am not able to utilize all the gears. Perhaps I need to upgrade this component. I hope this all makes sense. 😕
I currently have a double-crank. Would upgrading to a triple-crank be a worthy, practical investment? 😕
Thank you, Janiejones and Capwater for your advice. 😄