How to determine your wheel size and tire width for the Cannondale App

When you add a new Cannondale bike that included a Wheel Sensor to the app, the appropriate wheel size and tire width will usually be correctly set for your bike. The app relies on accurate wheel size and tire width settings to calculate the rolling circumference of the tire and convert the wheel rotations counted by the Wheel Sensor into speed and distance.

To check or change your Wheel Sensor settings in the App:

Go to Garage
Tap on Bike name
Tap on Sensor name ("SPD-BLE...")
If edits are necessary, tap Edit (pencil) icon in top right corner
Note: You set only wheel size and tire width, and the App will auto-calculate circumference

In some situations you may need to enter or change the wheel size and tire width yourself. Follow this guide if you are unsure what those are for you bike, wheels and tires. There are two options:

1. Use the Parts list in the App

If you have a Cannondale bike from model year 2019 and newer, the Parts section of the app should have the info you need:

Go to "Garage" and tap on your bike name
Tap "Parts"
Scroll to find the "Tires" section
Along with the description of the tire brand and model, you should see a size designation similar to these examples:
- - 650b x 47c
  - 700 x 37c
  - 27.5 x 2.20"
  - 29 x 2.25"
See "What those numbers" mean below for how to apply them to the app

2. Look at the sidewall of your front tire

You can also look at the sidewall of your front tire for a wheel size and tire width designation.

Note: do not look at your rim because the numbers there will not account for the tire and may be confusing.

Look around the sidewall of front tire for a printed or stamped size designation. You should see something similar to these examples:
- - 650b x 47c
  - 700 x 37c
  - 27.5 x 2.20"
  - 29 x 2.25"
See "What those numbers" mean below for how to apply them to the app
Note: If there are different front (F) and rear (R) tire sizes, use the front

What those numbers mean

Most wheel and tire size printed numbers follow the pattern:

wheel size X tire width

And almost all current Cannondale adult bikes use one of these four wheel sizes:

27.5"
29"
650b
700c

If you see...	... then Wheel Size is	Tire Width is	Notes
650b x 47c	650b	47mm	Ignore the "c" after the tire width. A tire width in double digits is always millimeters.
700 x 37c	700c	37mm	Any "700" wheel size is usually "700c"
27.5 x 2.20"	27.5	2.20in	A tire width in single digits is always inches
29 x 2.25"	29	2.25in