Bosch controller questions

[Dadam]

I've got a Cube eMTB with the basic Purion bar mounted display/controller.

I believe from reading online that it's not possible to connect a smartphone app or Garmin type device to the bike to read info like accurate battery levels, as it is on my Orbea. It seems I would need to upgrade to one of the later controllers like the Kiox or Nyon to enable this.

Thing is I quite like the ergonomics of the Purion, it shows speed, assist mode and you can cycle through odometer and remaining range info too, and turn on and off any integrated lights. I'd just like the connectivity to interrogate the bike via app while not riding. I don't want the sat nav, I've got my Garmin for that. I also don't want a massive screen in the middle of the bars.

Another point is the speed seems to under-read considerably compared to my Garmin (2-3 mph). Doesn't sound like much of an issue except I'm getting short changed on the assist cut off. Is it possible to recalibrate this?

 

[ebikeerwidnes]

As far as I am aware the USB connector on the Purion is of no use except for a dealer with the Bosch software - which they are very protective of

You can't even use it to charge anything while you are riding

There is no user level software - even 3rd party - software that will connect and extract even the most basic details

As far as the speed goes - I generally find that the distance on mine is pretty much the same as Strava logs - and I have tried it on other apps and had the same result.
And, of course, speed measurement is based on revs of the wheel and hence distance is closely related

I do find that the cutoff speed is above the 15.5 mph it is supposed to be - maybe just over 16 or so
I believe that this is due to
a) an allowed discrepancy that the manufacturers build in based on DVLA permission - another manufacturer has stated this on another ebike forum
b) a possible difference due to tyre pressures and depths

I have found that there might be a slight difference on speed measurement depending on the tyres used and the pressure. Naturally if the tyres are a bit soft then the effective diameter is less than if they are rock hard - and the speed is measured by revs of teh rear wheel - hence the number of revs per minute is used to calculate the speed
But if you pump the tyres up you increase the diameter and hence the distance per rev


Of course - increasing pressure also makes the bike more efficient so it feels like it is faster - which may be distorting my ideas


anyway - just my thought - treat with due suspicion!

 

[Espresso vecchio]

If the Purion speed is 2-3 mph below the Garmin speed, I would always believe the Garmin speed. Can you configure the wheel circumference, in millimetres, on the Purion as is possible on other Bosch controllers? If you can get into the Configuration mode (eg pressing the +, - and the on/off button simultaneously) try increasing the circumference on the controller configurator.

As far as the cut-off reading is concerned you may be having my experience, see below.

My Intuvia display always shows a distance travelled which is identical (give or take 50 yards) to my GPS Garmin even after considerable distances, eg 10 miles. Not bad at all.

Strangely however the motor cut-off comes at 16.2 mph on the Intuvia and 15.5 mph on the Garmin.. At the last service the Bosch computer printout showed the cut-off as 15.5. Similarly the current speed shown on the Intuvia always exceeds the Garmin's by a little under 1mph, as ebikeerwidnes above.

As the distance travelled is the same on Intuvia and the Garmin I just accept the speed discrepancies as 'one of those things' but believe the Garmin shows the true speed as it matches speeds on friends' Garmins when we ride on our road bikes.