The chainset, or crankset, comprises of the arm and chainrings, and each manufacturer such as Shimano, SRAM and Campagnolo offer a variety of different ratios to suit any style of riding. If you spend a lot of time riding around the lumpy Ribble Valley you may want to consider a Compact chainset (50/34) which reduces the gearing for you making it easier to get up the hills; on the other hand you may live in a flatter area and a standard (53/39) chainset could be the one for you.
Becoming increasingly popular are single ring chainsets, often found on mountain bikes where simplicity is key, but also being utilised by commuters and cyclocross for a fuss-free riding experience.
Not sure what chainset you need? Have a read of our Chainset Buying Guide