Bike Gear Calculator

Step-by-Step Guide to Using the Bike Gear Calculator

Input Fields

To begin using the Bike Gear Calculator, you will need to provide some input data. The following steps will guide you through each required field:

• Wheel Size:

  Select your bicycle’s wheel size from the available options. You can choose between ’26 inch (559mm)’, ‘27.5 inch (584mm)’, and ’29 inch/700c (622mm)’. This step is mandatory, so ensure you select one of the options.

• Tire Width (mm):

  Enter the width of your tire in millimeters. Valid values range from 20mm to 100mm. Make sure the number you enter is within this range as it’s a required field.

• Chainring Teeth:

  Enter the number of teeth on the chainring. The acceptable range is between 22 and 56 teeth. This field is crucial for accurate calculations, so ensure the number of teeth entered is correct.

• Cassette Teeth:

  Enter the number of teeth on the cassette. The valid range is from 10 to 52 teeth. It’s essential to enter the correct number to get accurate results.

• Crank Length (mm):

  Provide the crank length in millimeters. The values should be within the range of 165mm to 180mm, and only multiples of 2.5 are valid. This is another required field, so ensure accurate input.

Result Fields

Once you have entered all the input data, the calculator will provide the following results:

• Gear Ratio:

  This value is calculated as the ratio of the chainring teeth to the cassette teeth. It’s presented with two decimal places for precision.

• Wheel Circumference (mm):

  The circumference of your wheel is calculated using the formula: π * (wheel size + (2 * tire width)). The result is displayed with a single decimal place, followed by ‘mm’.

• Development (meters):

  This result signifies how far the bicycle travels in meters per full wheel revolution. It is calculated with the formula: (wheel circumference * chainring teeth) / (cassette teeth * 1000) and presented in meters with two decimal places.

• Speed at 90 RPM (km/h):

  This is your estimated speed in kilometers per hour if you pedal at 90 revolutions per minute. It’s calculated from the development in meters and displayed with one decimal place, followed by ‘km/h’.

• Gain Ratio:

  The gain ratio is determined using the formula: (wheel size + (2 * tire width)) * chainring teeth / (2 * crank length * cassette teeth). It is shown with two decimal places for accuracy.

With this guide, you should be able to successfully input your bike’s specifications into the calculator and interpret the results to enhance your cycling setup.