Black bike speedos are 20% over. Black is the fastest color!

 

that explains it its black

 

HD speedos are typically off about 3-4 mph at 70 or so.

 

Mine reads 3 mph faster than my true speed

 

My speedo is 3 mph fast and as far as the gas gauge and range, the less gas I have the faster they go down.

 

I rode into a gas station of fumes one day. Silly me... I held in the button for about 5 seconds when the display was on the countdown screen. This ended up resetting the remaining milage so when it said empty -- it was REALLY empty. I was in a sorry situation the next time I went riding because the bike showed empty and it was true... no reserve.

My lesson learned: The remaining milage may not be exact but it doesn't need to be. That little bit (gallon or so) of gas is a whole lot better than pushing your bike or waiting for a friend to show up with a gas can.

Live and learn. YMMV.

 

There are devices made by several companies that will adjust your speedometer. They are electronic and go between your speedometer and sensor.

I put one on another brand of bike and it worked well. The model I bought allowed me to set a percentage (positive or negative) that represented the inaccuracy of the speedometer and it altered the signal to correct it.

One caveat is is that it also adjusts the odometer. So, if you subtract 5% from your speedometer it will also subtract 5% from your odometer. You might want to check your bike but there's a good chance the speedometer is reading fast but your odometer is accurate. If you use one of these devices, your odometer will be off.

Here is a link to one brand of these devices.

http://www.healtech-electronics.com/

And here is a dealer that sells them.

http://www.calsportbike.com/sh/

Hope this helps.

 

exactly, they both err on the side of caution, just like all vehicles