Ok, I think I have got my head around gear inches and gear patterns (all hail Frank Berto!), my bike is coming with a nine speed drivetrain (Sora) complete with a 50/34 chainwheel and 12-27 freewheel, this gives me a high of 116 and low of 35 inches. This is what I believe the techies refer to as an Alpine set up suitable for novices and unfit/older riders because it's easy. I'm only really used to old 10spd's with friction shifters so on a test ride this was like manna from heaven to me, if I wanted to upgrade in six months and put a slightly more sporty gear pattern on the bike could I just change the cassette or would the derailleur struggle?