Built-in sensor on the driver wheel

[lucasmpr]

Hello :D. I really liked the idea of open rowing monitor.

I have a cheap Decathlon Rower120, and inspecting some videos I see my sensors are on the driver wheel (the one that you pull from, I don't really know what it is called) and not in the flywheel.

It was a little depressing as I understand that it will not work as intended.

In your opinion Is it better that I install some new reed switches (or some kind of incremental encoder) or try to build a new physics model with this little wheel in mind?