Carbon Drive is a free app that allows you to measure the tension of a bicycle, motorcycle, or scooter's drive belt. This app uses the microphone on your phone to convert the sound of the engine into a digital signal that can be used to measure the tension. You can also compare your measurements to the included charts to see if you need to adjust the tension.

Carbon Drive can also be used to find out the key parameters of your bicycle, motorcycle, or scooter. These parameters include speed ratio, chain pitch, and the distance between the rear wheel and the drive belt. You can compare your results to the included charts to see if you need to adjust the tension.

This app is very easy to use. Just click on the start button, and it will start recording. After that, you can download the results to your device.