How to make a Km only computer display mph???

[Falco Frank]

Ive actually taken the cheapo chinese (yes, small 'c') computer off now, instead of wasting any more time with it, even if it did have an impressive list of functions.

I thought I'd sussed it - for input it wanted a standard, wheel diameter in cm x 3.141

so I thought if I times this result by the conversion from Km to miles, 0.621 I'd get a mph display?

Seems not. for my 20" wheels its right at the bottom end of the calibration and is bloody erratic as heel.

Did I get it right or not?

Please be gentle

 

[slowmotion]

What units of measurement do you have to tap into the computer to come up with the wheel /tyre diameter?
It currently displays speed as km/h, and distance as km...is that correct?

 

[Falco Frank]

cm's are required and yes, display only shows Km and Km/hr.

 

[slowmotion]

I think you got it right. Multiply the wheel diameter in centimetres by 0.621 and the readout should give numbers in Imperial units.The problem is that you never can tell what the little processor chip has been told to display by the software inside it. It isn't quite like a calculator. Some numerical limits may have been set to exclude "silly" inputs.

I think....