Speedo over reading!?

[BiG DoM]

My speedo on my ADV was very accurate when compared to true (GPS) speed. I have noticed that the HP2 one on my bike over reads quite alarmingly in comaprison. Starts at about 10% and increases somewhat with speed. Is this usual for the HP2???

 

[addy3020]

With what wheels on?Enduro or motard?

 

[Bengaz]

Yes it is out quite a bit.
Flat out on the limiter is 135 but the speedo reads 145!!!
(on a private airstrip)

 

[BiG DoM]

With what wheels on?Enduro or motard?

Enduro.