So I am going to be upgrading my crank soon. I was thinking about the Sugino RD2 Messenger. First question is will it fit any square taper bottom bracket? Second is what is the mm sizing refering to? The third just has to do with the chainring/cog ratio...right now I believe I am running 48/16. It seems like a bit of an ordeal to skidstop for me. I see vids and others doing it while sitting down. Does the ratio effect the ease of it and if so what kinda ratios would make it easier to skidstop my bike in traffic without having to lean forward every time? I am coming from a Pake crank and my terrain is NYC if that plays a role...