It is threaded and the crankset bolts on. That said, when I got the bike, some idiot swapped crank arms and one is longer than the other so no I can't use the crank arms. That means I need new crank arms. I want to get shorter ones anyway because I tend to wreak havoc when I bike. I'm reckless as hell and aggressive, not in the sense dangerous to people, but like on turns I'll corner it over speed by a lot and lean in. I expect the 170mm that I have now to hit the ground. I'd rather get 165mm and a new ring. That said I was reading more on sheldon's site and now I have more to understand. I was thinking of going 44-16 but now with all this combined I have no idea what to get since I'd have to get the chain length right too. It doesn't bother me that there's a lot to it but i'd rather get it right now and not have to return parts.