Originally Posted by interceptor
My sensor for the computer is about two thirds down the fork (most look like the are about in the middle).
Does it matter? I was going to hold on to someones car to test for accuracy. Do I need to?
Does it not matter where you put the sensor when calculating the speed and total distance???
By setting the radius of the wheel, you know the circumference of the wheel. The magnet/sensor combination works by counting the number of revolutions that the wheel makes. From this it computes a rotational velocity with the help of a clock (i.e. revolutions per second). Using the radius of the wheel it can find the tangential velocity...
For the distance it just counts the number of revolutions. Each revolution means that the bike had gone a distance because that is how far any point on the wheel has moved in a circle, and since the wheels don't slip, the bike has moved that far...
In both cases,
the positioning of the magnet/sensor was not needed, as the total number and frequency of the revolutions are all that is needed given the radius of the wheel...
I put my wheel magnet at the location needed for the sensor to sit on the chain stay where it can pick up my cadence magnet on the pedal axle....