Accuracy of Purion speedometer/odometer?

[wjgrover]

I just purchased a 2019 arroyo. fantastic bike for shopping, commuting, and just plain rolling around town. I clocked the speedometer against my GPS Apple Watch, and the bike seems to claim a faster speed than the watch, by about 1 to 1.5 mph. my watch tracks fine with my road bike speedometer. anyone noticing speed discrepancies?
thanks, will

 

[Steve-H]

I just purchased a 2019 arroyo. fantastic bike for shopping, commuting, and just plain rolling around town. I clocked the speedometer against my GPS Apple Watch, and the bike seems to claim a faster speed than the watch, by about 1 to 1.5 mph. my watch tracks fine with my road bike speedometer. anyone noticing speed discrepancies?
thanks, will

We have road mounted radars in community areas that do publish a speed that is 2 km/hr less than my Purion display. So technically I will not get in trouble for having an illegal pedalec bike. And I just have to work harder to keep up with real road bikes that can average greater than 30 km/hr. They are definitely sweating and I have to work a little.

 

[Mr. Coffee]

I just purchased a 2019 arroyo. fantastic bike for shopping, commuting, and just plain rolling around town. I clocked the speedometer against my GPS Apple Watch, and the bike seems to claim a faster speed than the watch, by about 1 to 1.5 mph. my watch tracks fine with my road bike speedometer. anyone noticing speed discrepancies?
thanks, will

There are a mind-bogglingly large collection of reasons why you might have such a discrepancy. Unless you are really extremely systematic and run a lot of experiments in a very controlled environment you can't really know which one is correct and which one is not.

 

[6zfshdb]

Speed measured by consumer grade GPS equipment can be off by as much as 10%, especially at lower speeds. Accuracy depends on the number of satellites in "view" of your GPS and can be limited by topography, buildings, trees, etc.

 

[steve mercier]

you can also adjust the wheel diameter in the settings which will impact your speedo.