John West Wrote:
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> ................... I wonder
> what the fastest a Galloping Goose or for that
> matter a Galloping Banana ever went.
>
>
> JBWX
If the drivetrain from an auto or truck was used in building a rail car
or rail bus and the original speedometer installed, the RR drive
wheels would have to be exactly the same diameter as the original
vehicle tires to be accurate. Old speedometers were driven by a
rotating cable inside a protective sheath driven by gears in the OEM
drivetrain.
The change to digital speedometers gives options (in some vehicles)
to re-calibrate the speedometer for other than original equipment tire
diameter. At least within the electronic limits the OEM builder allows.
A car mechanic can recalibrate the speedometer for bigger or smaller
tires by marking the tire and measuring the ground distance for one
tire revolution and inputting the inches.
Pacing via a car or using radar is probably a better way to check actual
MPH on old rail buses than looking at an old installed mechanical
speedometer in the dash.