My Speedometer

[Vikingminn]

So let's say, hypothetically, my bike was in 3rd gear turning 11k on the tach and reading 108mph. If my buddy was in front of me doing about the same speed on a Speed Triple 1050. His speedo read 90 or so. My speedo would be way off, right? My bike has no engine, exhaust or performance mods.

 

[Umyaya]

Umm you would want to be side by side.... if he was in front of you then you would have to be going faster than him to gain the distance between you two. But ya your speedo factory is usually off .

 

[eru000]

Up to 10%, I've seen personally.

 

[dabner]

fixed mine with a SpeedoDRD

I figured mine was off about 10%, so picked up a SpeedoDRD. Very easy to install and operate, and cheaper than a Speedohealer.
When I installed the DRD, the correction was -6.6%, but that's according to its own calculations. I didn't check to see if it changed from stock, to after the install of the SpeedoDRD prior to inputting the correction.
None the less it's somewhere between 6 and 10%.
My question is, who wants to do 90mph to test their speedo? Wouldn't an average top speed of 65mph be adequate? Fwiw, I dialed my speedometer in at 100kph... any error above or below that is negligible or moot.

 

[eru000]

The speedo healer is percentage based, so it doesn't matter what speed you test at. I compared mine with the DRD at 80mph again GPS and it was accurate after correction.

 

[cmbcp]

GPS speed

My Garmin GPS indicates a speedo inaccuracy of 6%. 100kph on speedo = 94kph on Garmin.