I'm working on building up a bike but I'm stuck on a couple of pieces and the search on this site is awful. I picked up a wheelset on clist and it came with a 14t cog. It also turned out that there's no lockring, the kid did something to it and the cog is not coming off. What size crankset should I be looking for and should I be scrapping that wheel and starting over? I'll be riding mostly flat roads and just looking for something to cruise around with.