[MikeyZ]

No it's not, and that's not the case.

I don't think I have data handy, but my Garmin allows me to download traveled route data and display it overlayed on a map. At higher speeds, your sample rate becomes smaller because it's more difficult to manage a lock on more than 2 birds.

So, what I've found is that in the overlaid map you'll see a "line" drawn between two points which represents the route, and the line does not follow the path of the road. GIS data for known entities such as highways is very good in almost all the commercially availibile mapping software.

Your interpretation of "good enough" may still be off by 5 or more percent, so it's not an accurate measure.


It accounts for elevation change in the route details, but I highly doubt the speed calculation shown realtime does. I'd like to see that claim.

So you don't think if you went on x number of different highways and took your bikes speed versus the GPS speed, they would not be accurate?

Im talking on RT 95- Going 70 MPH (bike speed) for 20 or more seconds and looking at the GPS.

If GPS is not accurate, couldn't you say every way has its discrepancies?

[steves]

Radar is accurate because the hardware and sofware on the device is designed to account for the dopplar shift.

Every was DOES have it's own issues. I'm just arguing against using a generic GPS unit to "calibrate" your actual speed.

[astevens54]

Good post guys, I was just thinking about this very topic. So SpeedDRD or Speedhealer is the way to go if you want to correct speedo errors.

[il_ragazzo]

If you want to calculate your speed measure out a fraction of a mile. Hold a constant speed and use a stop watch to get how fast you traveled that fraction of a mile. Ergo your speed: distance over time.

Do this like 100 times, then take the average use that data to calibrate your speeding. It will be so accurate you wont care.

[christianguitarest]

fist, no there is not already a speed healer or another device equipped on the bike (darn, I like free stuff). Today I rode and tried real gps (not on my iphone) and found that Im only really 4mph off at 75. So I need to go 79ish to go 75. I think that my wife who I followed must have a led foot or misunderstood me when I said go 65 and maybe she went 75 in stead, the world will never no. But as far as I can tell Im off the factory 5%ish. Problem solved? On a side note I topped her out today, 147ish at redline angry engine mode, holy **** my pants batman!

[05RedKat600]

fist, no there is not already a speed healer or another device equipped on the bike (darn, I like free stuff). Today I rode and tried real gps (not on my iphone) and found that Im only really 4mph off at 75. So I need to go 79ish to go 75. I think that my wife who I followed must have a led foot or misunderstood me when I said go 65 and maybe she went 75 in stead, the world will never no. But as far as I can tell Im off the factory 5%ish. Problem solved? On a side note I topped her out today, 147ish at redline angry engine mode, holy **** my pants batman!

Yup, that's totally normal. IMO, not worth a speedohealer.

[MikeyZ]

On a side note I topped her out today, 147ish at redline angry engine mode, holy **** my pants batman!

But its really like 140