View Full Version : St1300 Speedometer Versus GPS Speedometer

09-25-2005, 04:16 PM
On my cars their speedometers have always been right on the nose when compared to the speedometer of the Garmin 2610..

However, I just got the Powerlet right side plug installed and hooked up my Garmin 2610. Today for a short right the Garmin 2610 had 15 feet accuracy with 7 satellites telling me where I am. However the ST1300 speedometer says that I am going 4.5 to 5 miles faster than the Garmin says at all speeds.

First, which do I trust the GPS or the ST1300? Again on the cars, the GPS has always matched the speedometers. If I trust the GPS, can I adjust the ST1300 speedometer?



09-25-2005, 04:22 PM
The GPS is right. I seem to recall something that can be done to adjust the speedo, but I haven't pursued it.

EDIT: Try this thread for more information. (http://www.st-owners.com/forums/showthread.php?t=5906&highlight=speedometer)

09-25-2005, 04:50 PM
GPS is more accurate. I've noticed that motorcycle speedo's tend to be off by about 10% at all speeds. Sorry, I guess I should have been more accurate with all of the mathematics professors on the site.:D

09-25-2005, 05:06 PM
I don't know if it is a full 10% off but I'll say about 5%-7%. This is a real issue when you do Ironbutt time rides like 1000 miles in 24 hours or 1500 miles in 24 hours. The GPS is correct and it is what I go by when I ride with it. I rarely if ever use the speedo when running the GPS.


09-25-2005, 05:15 PM
+1, what Curt said.


09-25-2005, 05:30 PM

I use the 10% rule; but, it isn't really correct...

Search for "speedhealer" you'll find Jeff B. uses http://www.speedohealer.com/eng/intro.htm and likes it.


09-25-2005, 07:13 PM
Unfortunately GPS is correct..The speedos are off..which for 14k I feel should be accurate..But since I don't want Paul from Texas coming down on my 'complaining, whining and *****ing', since most motocycles are off this is just fine. (Inside joke :rolleyes: few will get)

09-25-2005, 07:55 PM
Funny thing is that the odometer is only 2% off. Figure that in when you're trying to calculate MPG.


09-25-2005, 09:57 PM
Speedo healer or Yellow Box hundred bucks..
BC 800 bicycle speedometer around 20...
Greater than 1% accuracy on BOTH the
odometer and speed.


09-25-2005, 10:18 PM
I have instant message on and I am not getting notified.

09-29-2005, 04:23 PM
Speedo Verses GPS

My speedo is well under the reading given by the Garmin 2610.

At 70 MPH on the Garmin, St speedo reads 65MPH, and so on.

Okay, we could say that the speedo is reading on the 'Correct' side of the law in that you are normally 5 MPH below the speed limit for the road you are travelling on.

However, if you are running on the speedo and are 5 MPH below the speed limit for that particular road, watch out for the trucker or idiot in your mirrors, they may just follow the brown brick road and go straight up yer 'Jacksey'!

I run with the GPS, it gives me a more positive read out, but I am careful if I have to twist the throttle a little as there is a slight time lag before the GPS registers your adjusted speed, this could be enough to trigger a speed camera over here in the UK.



09-29-2005, 04:49 PM
Here in the UK where we have a gazillion speed cameras there are certain stretches of road where everyone apart from an idiot (or an already banned driver in a stolen car, hm, that would be an idiot) sits rigidly at the speed limit (according to their speedo).

Yesterday, I was on such a stretch a couple of times and I noticed how when I sat at the speed limit I was still a little faster than anyone else. The point being, if my speedo is off, everyone elses is worse :D


09-29-2005, 05:15 PM
i have read somewhere that due to calibration + - error all speedos are set approx 10% lower to take into account this calibration deflection error otherwise manufacturers would be blamed for all speeding if the tried to be spot on as the danger of them being high would have all the trafic agancies going mad, So having said this am suprised that Mr honda would have it wrong

ask a copper ( sorry am from the uk ) law inforcment officer to follow you the danger is if its wrong you get a ticket !!!!!! :bow1:

09-29-2005, 08:38 PM
Mine is off almost exactly 10% as confirmed by a calibrated Sigma.