Mountain Bike Gear Ratio
Gear ratios matter because they act as a force multiplier.
Mountain bike gear ratio. Ratio of the highest gear of your setup. It can in fact be said that front chainrings provide a wider gear ratio range while rear sprockets provide differences in gear ratios of adjacent gears. Gear ratios for climbing by todd maui hawaii howdy kris i ve been a mediocre mountain biker for 20 years. Here s a simple way to think about gear inch combinations.
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. Moving your mouse over the ratio will show speed you will achieve by pedaling at 100 rpm. My main passion on a bike is long steep low gear grinding hills think of grinding up the face of aspen mountain on summer read more. 3 is green 2 3 blue and below 2 red.
To keep things simple let s look at just 29ers. A sram 10 42 cassette has a very similar gear range but with a 32t chainring the lowest gear has a ratio of 32 42 0 762 and the highest gear has a ratio of 32 10 3 200. Colors group similar values. Using a gear inch chart is one way to compare gear ratios without riding the bike.
Simple just divide your rear cog size from your front chainring size. Know that this value does depend on wheel size. Say the chainrings on the bike are 48 38 28 and the cassette is a 9 speed one. How to calculate bicycle gear ratio.
For one revolution of the pedal your bike will travel a certain number of inches. The gear you re in is a simple ratio of the number of teeth on the chainring to the number of teeth on the sprocket in use. If you had to change to 30t chainring on the sram drivetrain you would achieve similar gear ratios as the shimano xt of 30 42 0 714 and 30 10 3 000. One cog in the front and back.
I am 53 now so i m old and set in my ways. While you might be just fine riding around on the flat ground climbing a hill of any size is going to be very tough. If you know their numbers just input them below and we ll calculate it automatically for you. Let s say you had a mountain bike with only a single gear i e.
For example with a 32 tooth ring and 16 tooth cog your ratio is 2 1. An intro to bike. Also take a look at our complete bicycle gear ratio chart below to see how your size compares to other gearing options. Shows table of all possible chainring sprocket combinations with gear ratio.