this whole idea started from a suggestion from a friend, and I am not set on it, just looking for info. I also don't have much of a budget, so I thought that not buying a front shifter and a single chainring front might save me some money. I'm honestly hoping to do this whole upgrade for under $100 if at all possible. If not, whatever I can do for that and plan on more later....

Is it possible to replace just the large chainring on my shimano stx crankset? And is there any specifics to look for in a 7sp cassette or should they be basically universal? I know about the break levers, that is simple and I can find that for sure [i'll probably look on craigslist].

If I do replace my whole crankset, can anyone tell me how to figure out my bottom bracket? Typically you need to know the width and weather its english or itialian correct? or am I way off? I wish it told me on that bike pedia site but that part is blank.

thanks for all the help so far... im definately going to ditch the 5/6spd idea, but I'm still considering the single speed at the crank, but if its truly cheaper to stay with a triple, including the extra shifter, i'll go with that.