Bike computers are surprisingly simple. Not unlike the calculators that we (used to) use in high school.
However, the way you input information is insufficient.
Typically you only have two or three buttons to work with. So you have to figure out the sequence before you can calibrate.
Regardless of the brand, you typically have something like this:
1. Press and hold the “reset” button with a pin or sharp object to activate the calibration flow.
2. Figure out which button will change the numbers up and down. Press that button repeatedly until you get it set up for the right number.
3. The last button will likely move you into the next setting flow. Press it and then go back to button #2 to adjust the number.
4. Repeat steps 2 and 3 until the settings are correct.
The most frustrating aspect is that if you get the sequence wrong, you typically have to restart the entire process. I try to view it as a video game so that I don’t get frustrated.
Online manuals are awesome. Search for “brand model manual” or “brand model manual pdf” to find the correct manual to work with. This will not only give you step-by-step guides but also give you the correct circumference to enter for tire size.
The most important measurement is your tire size. This measurement is how you can collect an accurate speed and distance calculation. If you get this wrong, everything else will be off as well.
Some computers have these sizes pre-programmed, so you simply have to select “700c” or “26 inches” to get the correct size.
However, there can be significant variation. If you are riding a wider 700c wheel, the sidewalls might be taller, creating a larger circumference.
For the most accurate measurement, it helps to mark a chalk line on your tire and a matching one on the ground. Roll your bike forward until the tire chalk mark has made one full revolution and then mark the end point on the ground.
Measuring between your two lines on the ground in millimeters gives you the number you should enter into your computer for the most accurate result.
The only truly challenging problem is how to jump between numbers in the same setting. This is especially a problem when setting the circumference. Sometimes you have to hold the #2 button for a second and then it will jump. On rare cases, they will have you hold the #3 button. It takes trial and error to figure it out.
Even if you don’t have the manual, with a little bit of trial and error, you should be able to set any bike computer. Just take your time with it and have fun!