I recently purchased a new 17t rear cog for my Rohloff speed hub. I'm in the process of buying the new 42t front ring. I remove several links out of my old chain (with the old 16t/38t ring set) to tighten it up a bit. I see ads for different sized chains, but I've never really paid any attention to chain size. I'm sure my current chain will not fit the new set up. What size chain do I need with the Rohloff set up (the 17t/42T set up)?