Bicycle Gear Ratio Explained

3 is green 2 3 blue and below 2 red.

Bicycle gear ratio explained. Here is a complete bicycle gear ratio chart of the most commonly used bicycle chainring and cog sizes. A bike with 30 or more gears is not an indication of a machine designed to break the land speed record any more than a bike with only a single gear assuming similar ratios. Colors group similar values. Gears however don t change by themselves and if you re confident you have the right gears on your bike making the most of your ratios is vital to avoid stalling and losing momentum.

The second method roll out a k a. The gear ratios you want to use for a hilly cycling holiday in mallorca are not the same as the gears you want for a time trial criterium club ride or city riding. The highest hardest gear will result in us travelling four times the distance of the lowest easiest gear for each pedal revolution. On some bicycles there is only one gear and therefore the gear ratio is fixed but most modern bicycles have multiple gears and thus multiple gear ratios a shifting mechanism allows selection of the.

Meters of development is calculated by multiplying the gear ratio by the circumference of the wheel measured in meters figure 1b. The lowest gear ratio on the bike might be a front chain wheel with 22 teeth and a rear gear having 30 teeth. The highest gear ratio is 28t with 12t. Our complete guide to bike gears takes the mystery out and will have you joining in with all the other bores banging on about ratios in no time at all.

The idea behind multiple gears on a bicycle whether it s an older 10 speed bike or a modern mountain bike with 24 gears is to let you change the distance that the bike moves forward with each pedal stroke for example a normal bicycle has wheels that are 26 inches in diameter. The result is that for the sprocket sizes above we have a set of 21 gears ratios which cover a range between 1 1 and 4 1.