Guys, I just started road riding with a group from work. I really like it alot. During our ride yesterday, my derailer flipped up over my rear cassette, and bent. Im looking to get a new one. My rear cassette, is a 5 speed, and the derailer, has the cable running into about even with the upper idler sprocket. The bike is a Schwinn Sprint. Im thinking, is it possible to buy a wheelset with maybe 8 gears, and a derailer to match? Sorry, for my inexperence, but Im trying to learn.