Calculate speed of a golf cart

[AirJunky]

Seems like these methods don't take weight into account at all. Even having a windshield on or not makes a difference with these things.

Use a smart phone to get a real number. There are tons of apps out there.

[JohnnieB]

Originally Posted by AirJunky

Seems like these methods don't take weight into account at all. Even having a windshield on or not makes a difference with these things.

Use a smart phone to get a real number. There are tons of apps out there.

The original question was about motor RPM rather than cart speed.

Smart phones still use the GPS satellite system and the clocks in consumer grade GPS receivers and smart phones aren't all that stable, so positioning isn't all that accurate (about 10 meters, at best, unless you average over time like surveyors do), so GPS speed readings can get a bit strange at times.

I've download tracks from my GPS that has my cart doing 100+ for short distances. Fortunately, my reciever is smart enough to know that is an anomaly and doesn't display it.

If you really want an accurate speed determination, time the cart over a measured distance.

What I use is a couple of wood furring strips nailed to the asphalt, exactly 20' apart.
I have about 25 yards of level road to get up to speed and start/stop the stopwatch when I feel the front tire hit the furring strip. That more or less cancels out reaction time.

According to my calculations, I consistently get 18.2MPH, according GPS I usually get 18 or 19 with a few 17s and an occasional 20 tossed in.

The speedometers that actually count tire revolutions will give you an accurate real time speed, if you know the tire diameter and can program it into the device.