Bosch Nyon distance and altitude inaccuracy...

[oceanskipper]

I've got a Bosch Gen 4. It came with the Smartphone Hub and I have since retrofitted a Nyon BUI350.

Both systems have an option to adjust the wheel circumference to (supposedly) make the speed more accurate. The smartphone Hub adjustment made literally zero difference and the Nyon makes a bit of difference mut not much and it's not accurate at all. I have tried the min and max allowed on both to see what happens and the answer is nothing on the Hub and not much on the Nyon!

Yesterday I rode the exact same route from start to finish with two others using Garmins and their distance covered was 119KM with 1583m elevation gain and my ride was 128KM with 1886 elevation gain - that's quite a large inaccuracy.

What first drew my attention to a possible inaccuracy was the fact that on the default setting the speed reads 16.7 MPH (26.9KMH) when the motor cuts out.

Does anyone else notice this?

 

[bazxa]

Mine seems reasonable accurate according to map cross reference.

 

[oceanskipper]

I suspect if you check it against say, a Garmin, you will find the same as me! Out if interest what wheels do you have and what circumference is the Nyon set to. Also if you ride along a flat bit if road and get up to the speed that the motor cuts out - what is indicated in the display? When my 29" wheel circumference was set to the measurement specified by the tyre manufacturer my speed reading when the motor cut out was 16.7 MPH. This was the same on the Smartphone Hub that I used before getting the Nyon.

 

[bazxa]

29 wheels should be set at 2.3meter however the bike is not working. Off to the dealer today to see if any codes are set . I can't distinguish between nyon display problem and motor or wiring. will get back when it is sorted.