how to increace the friction between tyre and road While designing a bicycle what are the designing factors to be considered to increase the friction to give more efficiency to the cycle.And what are the other factors that can be considered while designing.my interest is to design a modified bicycle to improve efficiency and decrease man power
Reducing friction (or grip in layman's terms) would cause your wheel to simply spin in circles when you pedal and you would fall down.  Increased friction between the tire and the riding surface is the goal of nearly every tire manufacturer.

You could easily coat your tire in oil to accomplish the lower friction you are talking about.