First ride with GPS

[EastCoast]

Got the Garmin 60CS about a month ago and today I finally put it on the bike to see how far off my speedometer is.

According to the speedo I was doing 90 MPH and the GPS says 83.3 max speed. Doing 45 to 50 by the speedo the GPS says I was doing about 2 to 3 MPH slower.

Is this about normal for the Busa or is my speedo way off?

 

[mjn]

The general consensus of opinion is about 7% off. That is where I adjusted my speedohealer to....sounds like yours is about right there.

 

[Juggler]

Another thing to be careful of with a GPS is that they're not real good if you don't stay at a particular speed for awhile. I don't know what their sampling rate is, but I wouldn't be surprised if it was seconds.

 

[BAMBOOBUSA]

I believe that juggler is right about the lag. If I was to really get a top speed I'd try to stay there for a while, like 2-4 seconds to let the thing catch up with it's sampling.

 

[greyrocket]

yep them speedo are way off. 130mph on speedo is
117mph gps

 

[emptys]

make sure you're also NOT changing
altitude... the GPS tracks differences
in location to guestimate speed. if you were
to climb straight up for a mile, it would say
you're doing 0 MPH

 

[manatrader]

Best way is to go out on the highway and time yourself in the areas where the state sets up mileage test. Most are 5 miles long and they are dead on for the mileage, do 60 right on the button and see what your time is. Then you know how far your off.

 

[manatrader]

Take your GPS with you and you will know if it on or off too.

 

[EastCoast]

I believe that juggler is right about the lag. If I was to really get a top speed I'd try to stay there for a while, like 2-4 seconds to let the thing catch up with it's sampling.

I know the GPS has a couple second lag time. My cars speedo is almost dead-on, and as I slow down the GPS is only 1 to 2 seconds behind.

As I performed the test on my bike I kept the speed constant for about 5 to 7 seconds to make sure the GPS updated.

 

[EastCoast]

if you were
to climb straight up for a mile, it would say
you're doing 0 MPH

That would be a neat trick, climbing straight up. Maybe in a space shuttle