A common misconception is that by opting for this style of bike people will ride slower and they chose to put up with the discomfort of more race-oriented bikes for this reason. It is often the case that the rider will actually ride quicker on the endurance bike as their centre of mass will be in much the same place relative to the pedals for generating extra power but they will also be able to utilise the bars more to pull on for helping further this power generation. Riders on a bike that is too aggressive for them will often spend substantial time with their hands on the tops of the bars and not into the hoods or on the drops where more efficiency can be gained. So by being able to maintain a better position on the endurance frame many riders will actually rider better and also for longer giving them a double advantage.
So in summary frame geometry is pretty unique for each bike and they all have to been considered on a case by case basis. Bike geometry can only really be compared by examining their geometry charts in greater detail and not through the arbitrary numbers assigned as frame sizes. However, as a good starting point it is certainly a good idea to ensure you are looking at the correct style of bike to match your riding before trying to determine the size that will work for you. If your are struggling with this please get in touch and we will be very happy to help!
Lead Bike Fitter at PFP Sweden