Cycle Analyst with PAS bug [solved]

I've got a CAv3 with the 12-pole PAS (all from em3ev) with a Mac10T

I've set up the torq-pas mode and it great fun to ride long distances without thinking about throttle; just feels like I'm superman

However I noticed one issue:

Normal case:
1. While riding, if I stop pedaling the power ramps down as per CA setting. If I restart pedaling the power ramps up smoothly and all is great.
2. If I'm riding and stop pedaling but the power hasn't ramped to 0 (there's usually an audible click when the motor disengages), and I restart again with less than 1/2 a turn (it might be 1/4 as I can't really tell), then there's a surge of power to the motor for a split second which then dissipates and then it continues as normal
3. This would also happen in the pathological case if one is stopping quickly using the brakes. The power hasn't completely gone but I might rotate the pedals a bit to balance causing a surge. Strongly applying the brakes stops it from crashing.

I thought it might be because having the 12 pole sensor causes the sensor to think I'm doing a really high RPM due to invalid signals, so it could be that. But it's fairly consistent that it's only when the power is coming off and I restart. If I wait till I hear the clank of the motor stopping then start pedaling whether quarter turn or anything then it's fine.

It might be a setting I need to enable?

Anyone seen this and knows how to fix?

Do you have e brake levers with cut off switches?

No I don't as I have hydraulic brakes. I did think that was one possible solution, but I feel its a 'feature' in the software too.

And also as this seems to happen when crusing and I stop/start pedaling without letter the motor stop or braking suggests even more that it's a feature of the system.

I solved it. So just in case anyone else sees this behaviour.

The problem was the fast threshold voltage setting. It was set to a high 10v/sec level which meant that when I would pedal on a restart, the software throught I was already at speed and would ramp up the voltage as quickly as possible.

Setting it to 2v/sec , with the normal ramp up level to 1v/sec fixes the problem.

Hope this helps someone out there

It is an old post, but I think the problem is still very relevant today: I have bought a Cycle Analyst V3 for the sole purpose of adding pas + torque to my 150amp sabvoton controller. However, I am noticing the same pas bug that you have. It leads to very dangerous situations where a powerful ebike will erratically go to full power when you stop pedaling for a moment (with the intention of slowing down a bit!) and then softly resuming pedaling. In fact, the behavior is so dangerous that my bike made a spontaneous backflip when I was crossing the street because of this spontaneous, unintended power surge, leading to lots of damage to my bike and body/skin!!

I think this is totally unacceptable and should get the highest priority to be solved. The only reason I bought the ca v3 is for pas + torque, and now it turns out the thing is completely useless for that purpose because of these dangerous power surges when you brake briefly (for brakes without additional connection to the ca v3) or when you stop and resume pedaling after a short period (0,5s?).

I use the following settings that result in very smooth and controllable behavior, apart from the power surges:

- throttle ramp up: max 5v/s
- throttle ramp down: 15v/s
- fast ramp: 0 amp (disabled)
- pas ramp: 1 v/s
- pas start: 0,15s/pulse
- pas stop: 0,1s/pulse
- sabvoton ramp up time: 0,01s
- sabvoton ramp down time: 0,01s

These settings are really smooth and safe during normal pedaling and throttling. It is only when you stop briefly that the dangerous voltage surge occurs.

It seems to be the problem that you describe: there seems to be a hidden timer that keeps pas active even when you are not pedaling. And when you start pedaling again, it tries to achieve the same power level as before resulting in a big spike in power to the motor. And consequently to unintentional wheelies or worse when driving through traffic.

This topic should be addressed in such a way that a user can deny the ca v3 to ever increase voltage that quickly. Please address this bug, or please comment how the settings should be adjusted so the spike can never occur.

And no, setting the overall amp and power limit is not an option. I did not invest a lot of money for a powerful bike + an expensive cycle analyst so that I would have to set it to really slow settings just to be sure that the ca v3 would not try to kill me at an unsuspecting moment...