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TSDZ2B low wattage on hills

brancky3

🧲 New user
Joined
Sep 8, 2026
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Location
France
Hello all!
I have a TSDZ2B with an EKD01 display on OSF v20.1C.6-update-6. I'm using the bike to commute to/from work, and for the most part it's running great. I have everything limited to 250 watts and 27km/h (speedo is slightly off, this is 25km/h confirmed on radar) to stay legal in France. My problem is with a pretty intense hill on my way home from work, it's about 20% grade which is extremely difficult without electric assistance. I logged my data from my ride home yesterday and it's very clear that the readings are substantially lower starting around 5:31PM, which is when I'm in a lower gear to get up the hill. There's no way I'm only putting out 6 watts myself during this climb as my data shows... I'm using either my 48t or 52t rear sprocket for most of the climb in order to keep my cadence decently high and not bog down too much.

Is there anything I could change in the parameters to troubleshoot this? Enable field weakening maybe?

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Nice graph! How did you generate that?

What kind of temp sensor are you using and where is it located? On my TSDZ2 I have a tiny type K thermocouple bead epoxied to the motor lamination, connected to a stand alone TC meter. When I climb a hill, I can see the temp rise in proportion to the steepness of the hill. Your temperature remains constant which is very odd.
 
Nice graph! How did you generate that?

What kind of temp sensor are you using and where is it located? On my TSDZ2 I have a tiny type K thermocouple bead epoxied to the motor lamination, connected to a stand alone TC meter. When I climb a hill, I can see the temp rise in proportion to the steepness of the hill. Your temperature remains constant which is very odd.
Hmmm I assumed there was a temp sensor already so maybe it's stable because there are no readings :D

I used the Apex Drive app to capture the data (TSDZ2 emmebrusa + EKD01 - app Apex Drive)
 
Hmmm I assumed there was a temp sensor already so maybe it's stable because there are no readings :D

I used the Apex Drive app to capture the data (TSDZ2 emmebrusa + EKD01 - app Apex Drive)
Stock TSDZ2B motor does not come with a temp sensor afaik.

Could the 6 watts indicated due to the Apex Drive app not reporting it correctly? How many watts do you think you were putting out during the climb?
 
Stock TSDZ2B motor does not come with a temp sensor afaik.

Could the 6 watts indicated due to the Apex Drive app not reporting it correctly? How many watts do you think you were putting out during the climb?
It's strange that the temperature fluctuates at all in that case.
I'm definitely putting out more than 6 watts, considering my heart rate is like 185. Normally my FTP is around 130watts so I think the wattage reported in the app is slightly low anyway, but I can't deal with this hill if the motor is only putting out 30 watts for me.

I'm going to switch back to the stock firmware to see if there's maybe a hardware problem as this seems really unusual
 
What I see in "basic settings" is that you haven't calibrated the torque sensor.
The estimated value is necessary for an approximation of human power. Alternatively, you can calibrate human power separately using a weight.
These calibration procedures you can find inside the configuration manual par.4 from page 7

Maybe this will give a better human monitoring value.

Also I understand you want your Tsdz2B street legal. For that you have limited your power to 250W.
Realize that you have limited the max. power to 250W and not max. continues power. It is max. continues power that must be 250W. The max. power may be a lot higher and you are still street legal. For example Bosch CX 250W motors can even run 750W max. power and are still street legal and even the lightest motor can give 400W max. power.

FYI EN 19154
The maximum continuous rated power shall be measured when the motor reaches its thermal equilibrium as specified by the manufacturer.
(thermal equilibrium: temperatures of motor parts do not vary more than 2K per hour)


The factory has rated the Tsdz2B 36V 250W 4200RPM to give the conditions to reach max. continues power.
With power above 250W the temperature will vary more than 2K/h. But because you don't want to overheat and burn the motor this could not be continues power, but it is max. power or peak power for a shorter time.
If you set power max. to 450W and current to max. 14A, imho you will be safe against overheating.
If you add heat pads inside the motor and/or add a temperature sensor too, you can set it to higher values.
 
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