[Zook650]

We have a Magellan Sportrak on the 650 and at 100km/hr indicated on the speedo, the GPS indicates 92. Which one is more accurate? Any ideas?

 

[Jim]

speedo

I have found that typically spedometers on bikes read 5-10% fast. In 1976 I owned a Suzuki 750 (water buffalo) and a friend of mine was a cop. Radar at that time showed 55 when the spedo indicated 73. It's closer today, traffic flow around patrolled areas is about 5% faster that posted . Haven't done a radar check yet but plan on it. I would tend to agree with the GPS. my GPS (Garman) matches our car on trips but haven't tried it on our AN650.

 

[Tony]

GPS vs. Speedometer

I agree. My GPS indicates at least a 10% error in speedo, varying with speed. The higher the indicated speed, the greater the error. I believe the GPS is more accurate

 

[billyboyj]

I have used a Garmin E-trex Vista with my car and my Volusia. It consistently indicated about a 10% differential. My research has indicated the the GPS is true MPH. Have not yet installed the GPS on the Bergy.

 

[Guest]

[No message]

 

[Jim]

spedo error

Verified on my AN650, using a Garman 12 GPS. Indicated 30 GPS 27, Indicated 61 GPS 55, Indicated 85 GPS 77.

 

[ajwood]

Dare!

I've had the opportunity to use the Sherrif's Department radar trailers a few times around town.

*Trailers left unattended on the shoulder of a road, warning drivers who speed over the limit with its big digital display and red/blue warning lights.*

Every time I go past one, the display shows exactly what the Burgman's speedometer does.

 

[Kenny]

Now this is an interesting discussion.

I also have a portable GPS. I haven't checked speed with it, but now I'm going to make it a point to do so.

I too have passed those police radar checks, but they have never matched my indicated speed. They have always shown less than what I'm indicating - sometimes more than 5mph less. As a result, I have been wondering if my speedo is accurate... One thing I was thinking is that perhaps because the profile of the bike is so small, that it can't get an accurate reading. Anyone have any thoughts on this?

I'll try to post my GPS results here too, to add to the data....

Kenny

 

[Guest]

[No message]

 

[Jim]

GPS

Hey Kenny any results yet?

 

[Kenny]

I haven't had a chance to do any high speed ( > 45 or so) testing because I'm going to have a friend help me. It will be safer if I can keep both hands on the bars. I don't have a mount for the gps.

I did some low speed tests though, and the bike speedometer does indeed read high. If I recall correctly, it was about 5 high around 40-50, and a bit less as the speed decreased.

I'm planning on doing it more scientifically, where we will write down our results at each speed.

Hopefully I'll get that done soon. 8)

Kenny

 

[Jim]

GPS

My GPS may be smaller than yours, but I rubber banded the unit to the left handlebar towards the inside between the bars. I did the speed checks alone.
A good lonely road of course is Always nice.

 

[Kenny]

Ok, I finally got the tests done. Here are the results: (in MPH)

Indicated....GPS..............Error

15..............13................2
20..............18................2
25..............22................3
30..............27................3
35..............32................3
40..............36................4
45..............40................5
50..............45................5
55..............50................5
60..............55................5
65..............60................5
70..............63................7
75..............68................7

Notice how it's exactly 5 high where we usually cruise? How convenient....

Most interesting thing to me is that in a 70 mph zone, you have to be doing about 77 or so just to be at the speed limit... good to know to prevent getting squished.... :wink:

I'll have to try the rubber band idea and do some higher speed tests. I just didn't want to go any higher than 75 indicated with a passenger...

Kenny

 

[Greg]

I was hoping not to get involved in this topic but here goes ...

Has any body tried there GPS in there cars to see if readings are out. ??

I'm shore the same result will appear.

So if we are all 5-10% under actual speed we don't need to compensate.

Rgds Greg ...

 

[Jim]

GPS

the gps read out in both my truck and my full size car are right on, most bikes are 10% off

 

[Kenny]

My GPS matches my car exactly....

Kenny

 

[Walt Bryant]

speed readout with GPS

Have a Burgman 400K3 with 850 miles on her, I checked the speedometer when I first got her and found in to read a little fast compared to my GPS I had a Honda Reflex before the 400 and I had checked it as well and found it to be very close to the GPS at speeds below 50mph but when I got the Burgman 400k3 car's were passing me a lot more on the route that I always take which is 2 lane so I brought my GPS with me one day and found the speed of scooter to be 5+% fast at most speeds but it reads very close to my friends Honda Helix and his Honda Rebel. There seems to be a little more tire slipage at high speed.

 

[Bill Trammell]

Speed & Distance Errors

I posted on the 650 Board the results of both Speed & Distance Errors on Angel's new Burgman 650

Oct 29: Subj: Spedo Error vs Odometer Erros

 

[ajwood]

It's time for me to develop a BurgyModule that remaps the Speed Sensor to give calibrated readings in the mph/kph display.

As new sizes of rear tires become available, a push of a button (new table map) would keep readings accurate.

 

[Jim]

speed mod

That would be great! Keep us updated, I,m interested.