loquin
Well-Known Member
Re the frictional losses. You would be looking at bearing friction of the axle, plus rolling resistance of the tire, and the chain losses.
A well maintained axle/bearings should add very little power loss - I would estimate it to be on the order of 1 to 2% power loss.
Rolling resistance varies widely, and is difficult to estimate - it depends upon the tire geometry (narrower tires offer lower rolling resistance,) rubber 'hardness' ('harder' rubber deflects less under load, and has lower rolling resistance, at the expense of traction,) air pressure (higher pressure means that the tire deflects less under load, and therefore has lower rolling resistance,) and static load (the greater the load, the greater the tire deflection, and subsequently, a higher rolling resistance.) Maybe someone has access to some data on tire rolling resistance.
Drive chains, when properly aligned and maintained, are among the most efficient means of power transfer - on the order of 98% efficiency in power transfer from driving sprocket to driven sprocket.
A well maintained axle/bearings should add very little power loss - I would estimate it to be on the order of 1 to 2% power loss.
Rolling resistance varies widely, and is difficult to estimate - it depends upon the tire geometry (narrower tires offer lower rolling resistance,) rubber 'hardness' ('harder' rubber deflects less under load, and has lower rolling resistance, at the expense of traction,) air pressure (higher pressure means that the tire deflects less under load, and therefore has lower rolling resistance,) and static load (the greater the load, the greater the tire deflection, and subsequently, a higher rolling resistance.) Maybe someone has access to some data on tire rolling resistance.
Drive chains, when properly aligned and maintained, are among the most efficient means of power transfer - on the order of 98% efficiency in power transfer from driving sprocket to driven sprocket.