For those who have a Gamrin ( External ) GPS. Do you notice a difference between the Speed Odometer and the GPS. I notice at 80 mph on my Speed-o the GPS is saying 76 mph. I am guessing that the GPS is incorrect due to the distance it needs to travel. The only reason I asked is because I read on the fourm that after the radio upgrade riders started to notice an incorrect readin on their speed-o. Any advise.

 

Ah'm tryin' ta figger out how you'd think the GPS wuz wrong!?? Speedo's on every m/c are "optimistic" - generally rangin' between 'bout 3-7 percent higher than actual speed. On mah '07 UC, the error is 'bout 3%.

 

Police raidar matches my gps asuming its just been calibrated speed-o is about what tex said 3% off but more or less at various speeds

 

Got me curious. My hand held Garmin and my Sporty were dead nuts. I'll take the gps out tomorrow.

 

I think the gps is accurate. I checked mine with stationary radar sites that are set up on the highways thatshow you your actualspeed.

 

Per my GPS, my Street Glide speed-o is off 5mph at about 60mph

Bob

 

The specs on my Zumo are that the speedometer is accurate to .05 mph. I would trust your gps exclusively!

Paul

 

i also have a garmin 2720 and have noticed the difference of 3 mph consistant at all speeds and the speedo is faster i lean more towards the gps being acurate also.

 

Fairfax Motorsquad guys we work with for our Rolling Thunder Pre-ride (www.rideofthepatriots.com) always tell us to trust the gps over the speed-o

Since they're the one's that tag us, I tend to beleive them.

Just my 2 cents.

 

Using a stop watch between mile posts, my Ultra is smack on at 60mph, but is optimistic above 65. 78 indicated is 75. (4% over)