True, but i am definitely hitting above middling on the flats - i get that 'bobbing' rhythm as i start to try to accelerate without enough cog to turn! The 16t will be going on this weekendThis is bang on the money. To up your average speed you dont need to worry about your top speed. Concentrate on the sections where you just plod along.
You spend much more time at middling speeds. Very little at what would be your maximum.