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.
What you want to minimize (within reason) is "drag" or "rolling resistance" caused by the tires in contact with the road. This is a function of tire width, tire pressure, tread design, and the characteristics of the rubber. Plus, of course, the characteristics of the road.
Generally, higher pressure reduces contact area (for a given weight) and hence rolling resistance. Smooth tires produce fewer losses than lugged tires, and hard rubber fewer losses than a softer rubber. (But at some point the tire is harder than the road and no additional gains can be made.)
Further, having tires that are too hard can reduce overall (human-operated) bike efficiency because vibrations are transmitted through the tires and bike to the rider's body, where they are dissipated as heat (and fatigue). Ideally, the tires are soft enough to absorb moderate bumps, but the rubber and tread are designed such that very little energy is absorbed, but rather "reflected" back to the road as the bumps go the opposite direction.
The ONLY thing bike design has to do with the friction between the tyre and the road is weight related, assuming tyre design does not count as part of bike design.
Heavier design of bike = more friction, Lighter design of bike = less friction.
I for one would not consider "designing a bicycle" in the context of this question to be designing the tyres, any more than I would consider it to be designing the drive terrain. As far as I understood it and I may be wrong it is reasonable to consider "design a bicycle" in the above question to be frame design + component selection.
However if the question actually means, as Mσᶎ believes, the design of any part of a bike then following should be done:
- You should design tyres (or tyreless wheels) as thin and hard as possible (maybe out of wurtzite boron nitride) for absolute minimum contact area. Then you should (after inventing a method to do so) coat those wheels with Cerflon for minimum coefficient of friction.
- You should design and integrate into your bike a device to perfectly smooth the path ahead of you and coat it in an extremely hard substance which is then in turn coated with Cerflon.
Diamond and poly(1,1,2,2-tetrafluoroethylene) would be reasonable substitutes for wurtzite boron nitride and Cerflon respectively.
I know it is not much more than a link only answer but this is a very good discussion.
Narrow and higher pressure is good. But on a ruff surface too much pressure can cause bounce and more resistance. Generally, smooth treads roll better than coarse treads.
Rolling resistance, sometimes called rolling friction or rolling drag