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Author Topic: 2016 FXS 77 ft-lbs torque in app  (Read 619 times)

domingo3

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2016 FXS 77 ft-lbs torque in app
« on: May 19, 2017, 06:30:13 PM »

  The motor was recently replaced on my 2016 FXS under warranty.  I only use the app infrequently, but I distinctly remember that prior to the service, the torque would reach a maximum of 70 ft-lbs as reported in the app, which matches the specs exactly.  Now, I will frequently see 77 ft-lbs of torque on the app at full throttle.  If you have an explanation, you can skip my stream of consciousness below.

  This brings up so many questions.  Since the last time I used the app until now, I've updated to the new version of the app, the motor was replaced, and the firmware was updated.  I looked at the specs on the 2016 vs 2017 FXS.  The motor is the same on both models, but the controller is different.  They didn't give me any paperwork after the warranty service, so I don't know what was done, but would they have replaced the controller as well?  I haven't seen over 400 amps, much less over 500 amps, as reported by the app.  Not sure if the app is accurate, or what conditions would lead to max current, but I don't seem to see it.    How does the app/bike determine the torque anyway?  I really doubt there is a force sensor in the drive train.  Does it just calculate based on factors such as current and RPM?  Is it just a calibration issue with the app misreporting?  Specs for 2017 say max torque of 78 ft lbs.  I've definitely only seen a max of 77 ft lbs.   After being off the bike for an entire month, I don't think I'd notice a 10% difference in torque.  Could they have made a mistake on reprogramming something on the bike?  Unless I put the bike on a dyno, how can I know if this is a real increase in torque or an illusion? Is there something to look at on the bike to find clues?
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Burton

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Re: 2016 FXS 77 ft-lbs torque in app
« Reply #1 on: May 19, 2017, 06:56:21 PM »

I believe, and I could be wrong here, the torque (in Nm), is "calculated" by the controller ... Inside the controller you have a "max torque" number for the motor, and you have a "max discharge" number in Amps for the battery. There is no force sensor anywhere I know of. It simply looks at amps / voltage drawn /rpm and the gear ratio ... if the torque displayed is torque at the motor's shaft then the controller only is likely the number used. If it is displayed as a number at the wheel then the controller number likely goes through the MMB or the app itself before the app as it needs to apply a gear ratio which isn't used inside the controller.

I don't know if the controller on a FXS MY16 is the same as my size six sevcon but if it is this is likely the case.

Now, the max discharge rate is a RDPO variable sent from the firmware on the bike. This sets the limit programmatically by zero and overwrites changes to the controller. People who modify these settings have to fill in this data with dummy data so it is still "addressed" but not used by the controller. This means if zero changes them via firmware updates they will propagate to the controller via these RDPO values.

So now all that said ... if you had a reaper dongle I would say issue a dumpall command to see if the ratio for the bike has changed which would affect the torque displayed assuming it isn't torque at the motor. ;)
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Say10 15FX 16FXS

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Re: 2016 FXS 77 ft-lbs torque in app
« Reply #2 on: May 19, 2017, 08:50:08 PM »

Why was the motor replaced?
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domingo3

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Re: 2016 FXS 77 ft-lbs torque in app
« Reply #3 on: May 19, 2017, 09:28:04 PM »

Why was the motor replaced?

I experienced sudden rapid deceleration multiple times when pushing the motor hard.  Multiple ride-through faults were found in the logs, so I was told to bring it in to a dealer for remote diagnostics with Zero.  After this, I was told the motor was faulty and needed to be replaced.


Details are here.  http://electricmotorcycleforum.com/boards/index.php?topic=6567.0
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Ireek

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Re: 2016 FXS 77 ft-lbs torque in app
« Reply #4 on: May 20, 2017, 01:53:13 AM »

There is a 2016 FXS at my local dealer that has had the motor replaced, it is a new bike, dealer told me that it was making a strange noise and was replaced under warranty and it was an updated power unit, take this for what it's worth, this is just what they told me...
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