Hi Nataly,
I can comfortably
Hi Nataly,
I can comfortably sit on about 25kmph, not sure about the flat ground part, this is Tasmania which means hills & head winds abound.
I have my bike set up to climb better with a bit more weight on the front wheel and a fairly upright seat back, when I was setting this frame up I had the seat laid back and was very aerodynamic and faster on the flats but not as good on the steep bits, so IMHO you can customize your bike to suit your riding conditions.
My bike has 26" wheels, Mountain bike gearing 22,32,42 fr &11 to 28 rear, 1.5 Schwalbe Marathon tyres, makes it a very reliable commuter/tourer,
If you want a bike for more speed you could build one up with 700c wheels & skinny road bike tyres, should be a few examples on this site.
Not sure where you are but if you can get down to Geelong Kim has some test bikes to try