BAFANG CST AND C961 max speed

[zendan]

Dear all, experts and users of the BAFANG CST with C961 display,
I would be very grateful if you are able to solve this my issue.
I have an e-bike with BAFANG CST rear motor with torque sensor, 36V battery and C961 display. I tried to increase the speed limit by using the C961 display menu setting, forcing the max value at 50 km/h. The problem is that even if this value has been correctly set and stored, the max speed of the e-bike remains at 27-28 Km/h.
Is this an issue that can be solved in a different way (by Software or hardware), or there's no way to change the max speed limit considering the CST, battery 36V and BAFANG C961?

Thank you very much in advance for the answer.

 

[d8veh]

There's several versions of the bafang CST. None of them will get anywhere near 50 km/h at 36v. What are the markings on the motor, which might give a clue as to which version you have?

 

[leo99]

as d8veh said we need the model of the motor.
You will most likely have to change the battery for a 48v and maybe the controller too if you want more speed.

 

[zendan]

Thank you for your fast replies.
The code impressed on my Bafang CST is: CST 36V250W 27.5
and below: 1504287219-6
I have a MTB with 27.5 wheel size .

 

[leo99]

I quickly looked around and it seems that there is two models for the bafang cst one at 205 rpm 26km/h and one at 250 30km/h. those speeds are with 26 inch wheels so a bit faster with your 27.5inch wheels. I imagine that you have the 205rpm motor.

If you want to go faster you will have to go with a 48v or 52v. a 52v pack should get you 35km/h if you have the 205rpm model or 40km/h if you have a 250rpm model. If you change your pack you will most likely have to change the controller too.

leo

 

[d8veh]

Plus 1 to the above.

You can tell if your motor has maxed out or whether it's speed limited by a simple test. Unlimited, its maximum speed depends on the battery voltage, so charge up your battery and spin the wheel to maximum. That might be difficult with a torque sensor, though, unless you have a separate throttle. Note the speed. Run your bike until the battery is nearly empty, and repeat the test. If it's significantly slower, it's maxed out without a limit. if the two speeds are the same, it's limited.

 

[zendan]

Thank you very much. After the test you proposed me, I have to say that at this point my motor is limited.

An other information: do you know where can I find some software to program my controller Bafang specific for the hub motor?

 

[d8veh]

Try this. Let us know if it works: