Cannondale motera Leo 3 Bosch smart system incorrect miles being taken

[Pazman]

My 4 month old cannodale motera neo 3 Bosch smart system is playing up .
i just did a 22 mile ride ( according to my gps watch ) but my e-bike says the ride was only 16.5 miles .
I also now have power assist up to 16 mph instead of 15.5 .
my bike was in the bike shop last week for an error with the sensor/magnet which was causing the bike to cut out intermently giving no power assist.
since being fixed i have no power cut outs or error codes and it rides great ,but i have noticed the miles are not clocking up correctly .
When it was in for repair they said they just cleared the error codes and told me to put the original bosch magnet back on the bike which i did .
Any one had an issue with the miles not being measured correctly by the bike ?

 

[Zimmerframe]

It sounds like either the magnet is miss aligned, the sensor is faulty or there's a cable fault. Checking the magnet alignment and following the cable along and cleaning the connection at the motor end are the easiest things to try first.

 

[Pazman]

It sounds like either the magnet is miss aligned, the sensor is faulty or there's a cable fault. Checking the magnet alignment and following the cable along and cleaning the connection at the motor end are the easiest things to try first.

I fitted a new speed sensor with attached cable when i first got the error coeds and power loss as the magnet looked to be fine .

 

[Zimmerframe]

OK .. so most likely not the cable/sensor.

You said the shop told you to put the original magnet back on, which means you were running something different, presumably because of some other change - as you wouldn't change it just because you preferred a different brand of magnet

You could space the sensor closer with a washer behind it .. start with 1mm and go from there. Maybe what you've changed has increased the distance so the hall sensor isn't getting a clear reading.

 

[Pazman]

OK .. so most likely not the cable/sensor.

You said the shop told you to put the original magnet back on, which means you were running something different, presumably because of some other change - as you wouldn't change it just because you preferred a different brand of magnet

You could space the sensor closer with a washer behind it .. start with 1mm and go from there. Maybe what you've changed has increased the distance so the hall sensor isn't getting a clear reading.

Well I changed the wheel to mavic wheel with blade spokes ,so the bosch magnet would not fit the blade spokes . I had to use the mavic one which came with the wheels .
I had done over 300 miles with this setup without any issues.
After the error codes last week I filed one the blade spokes down just enough for the bosch magnet to fit.
The space between the magnet and sensor is now well within spec.
I need to test it out tomorrow again this time with 2 different GPS watches and see whats what .
Maybe the bike is correct and my galaxy watch 5 pro is at fault?

 

[Pazman]

Todays ride i a distance of 14.53 on galaxy watch pro , 14.7 on Komoot in my phone and 15.8 on my Bosch Kiox.
i have no idea why the distance was so far out but today is much better.
i have the wheel circumference set in the Kiox as 91.6 inch fro my 29’ wheel with 2.3 width tyres .
I cannot think which way i should adjust that setting to get the bike more accurate with the sat navs ?

 

[Zimmerframe]

You could try setting the wheel circumference to 84.6

 

[Pazman]

You could try setting the wheel circumference to 84.6

I’ve just sat on the bike with 28 psi and rolled it one full turn which measured 88” so it was out at 91.6 original settings used
hopefully thats it sorted .