Signal for a electronic speedometer

[wkuehnis]

Hi,
I am building a A Speedster.
I use all Gauges with the same design .
Now I need the signal for the electronic speedometer.
Does anymode have a solution?
I think, the only way is the position at the torqueTube, where the original cable driven speedometer is connected.
Here I can get the signal from a rotating cable or Pin and transfee it to a electronic signal.
Does anybody has a drawing of such a solution?

Thanks for help
Willi