Calculating Gear Ratios for a Bicycle

[heat transfer]

hello, i got this project on how a bicycle operate, and my part is to calculate the gear ratios of the bike, so can anyone share with me the step on finding the gear ratio of bicycle

 

[GOD__AM]

I think you just divide the number of teeth on the front sprocket by the teeth on the back, e.g., 100 front 10 back = 10 to 1

 

[Naty1]

Post # 2 is correct...It is also correct to compare the radius of the two gears...which is proportionate to the # of teeth since C = 2(pi) r...noting that the teeth on the two gears must be the same size to mesh...

This is analogous to the mechanical advantage of pulleys...say one on an engine and another on an accessory, like an alternator...where comparison the radii gives the ratio of the rotational speeds...