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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Kaneda on September 12, 2020, 04:39:17 AM

Title: SR/F hesitation stall issue
Post by: Kaneda on September 12, 2020, 04:39:17 AM
Hi, I need help describing a intermittent issue I am having with my new Zero SR/F 2020.
 The last week of July, the issue began. Upon acceleration a mitigation of torque occurs, a bumpy sensation. The bike hesitates and fails to accelerate and can leave you in a really bad spot on left turns in traffic.

Initially I thought it was the belt. I took the bike in at 700 miles for service and a new belt. I told the dealer The issue I was having, we both agreed it must be the belt. The issue subsided for a while, Now it’s back. At this point there is little consistency With what I say that has much certainty. All I’m trying to do is narrow the issue down so that the dealer can actually contact Zero for assistance.
What little I know:
-It only occurs under load, I was able to lift the back end up and set the cruise control on- no issues
-I’m getting closer to thinking it may be temp related. The ride to work I usually fine. The ride home after sitting in sun is the scary one.
-it seems most notable in the 0-15mph range, as the motor struggles, sometimes not able to get over 10mph in 20 yards. After 15 mph, acceleration is more pronounced, but a mutter still is audible from belt motor area.

I’m not sure the the motor is set up, but one way of describing this might be a motor that is missing power.

So, has anyone else had this issue?
How do I begin to describe this, is there any more tests I can take to help narrow this down?
I have a video that is a little help in describing the sound and sensation, but even at 4 secs too big for the forum.
Title: Re: SR/F hesitation stall issue
Post by: Crissa on September 12, 2020, 05:05:59 AM
That's a weird one!

I'd wonder if it wasn't a connector to the motor controller...  (Since it's more pronounced when it changes temperature.) Or in the motor controller.

-Crissa
Title: Re: SR/F hesitation stall issue
Post by: Shadow on September 12, 2020, 08:12:28 AM
Does your local dealer have any experience with troubleshooting Zero Motorcycles vehicles? Do you have another dealer you can try taking the bike too?

Could be... brake calipers not floating correctly so they don't release?  Motor controller not commissioned or permanent magnets in motor have worn-in and do not match the settings? User error (not necessarily rider error might be some dealer induced assembly issue)?

There would be visible wear on the belt if it were a problem.
Title: Re: SR/F hesitation stall issue
Post by: Kaneda on September 12, 2020, 11:10:25 AM
Thank you both for the response. Do either of you know anything about the bad boards in the 2019 SR/F? I remember hearing about that, or was it bad cables to boards?

I left work very late and had no issues with the bike.

I would be more inclined to think some of the IC chips on the board, or the board that controls throttle or power has a issue. It’s not brakes being grabby.
As far as a local dealer, no, they sell So few zeros I doubt that they have much experience poking at them. I’m 230 miles from the dealer I bought from. The closest dealer is 142 miles. Both dealers are on the coast, where the air is cooler and the issue will likely not present itself.
IF it’s temp related, which is still a question, so far the times it occurs are above 82 sitting in sunlight. If it’s in the shade or early morning or later in evening, it seems to subside.
Title: Re: SR/F hesitation stall issue
Post by: Richard230 on September 12, 2020, 08:06:51 PM
I had a somewhat similar issue (but not exactly the same) with my 2012 Zero. The problem turned out to be a defective throttle assembly. When that was replaced, I never had another problem with stalling.
Title: Re: SR/F hesitation stall issue
Post by: stevenh on September 12, 2020, 11:21:35 PM
Can you dump the logs and email them right to Zero (and yourself)?  You may see throttle faults if that's the issue.

Steve
Title: Re: SR/F hesitation stall issue
Post by: Crissa on September 12, 2020, 11:41:40 PM
Do the logs carry the throttle input levels?

-Crissa
Title: Re: SR/F hesitation stall issue
Post by: Auriga on September 13, 2020, 02:14:17 AM
The SR/F logs do not contain throttle values, but would log any errors/messages recorded in the system.

I do not think the community can decode FST platform logs, so I'm not sure he'd be able to read them.

I'd email them to Zero and/or your dealer with a specific timestamp of when the issue occurred. I'm assuming no dash errors appeared, but if they did that'd be helpful too.
I'd say something like you found your acceleration limited under certain conditions, for example on the ride at 12PM on the 10th. That's enough to start looking

Did you get your motor commissioned in your 600 mile service? This sounds like it could be a motor/encoder synchronization issue. It's also normal to experience limited acceleration when at lower SOCs or when approaching thermal limits of the battery/motor/controller. Either of these sound plausible based on your comment that it only happens under load and after sitting in the sun for a while.

Either of these things should be visible in the logs, if you don't hear back from HQ in a couple days you can call them. They're not open on weekends though.
Title: Re: SR/F hesitation stall issue
Post by: Kaneda on September 13, 2020, 10:29:30 PM
I had service done last month at 700 miles. I tried my best to describe the issue, Asked them
To check the log for any errors. No errors, the tech test rode it, every thing appeared at the time to be the belt which had a small bulge from a rock or something.

Zero will not communicate with me on this issue, they cut me off mid sentence and told me to contact a dealer twice during my call. Again I just trying to find the right conditions and language that will assist the dealer in a solution. Otherwise it will just sit around for months outside at the dealership. Should I try calling again?

I have not had the bike much under 30% SOC.
The only thermal limits I am aware of is what is on the display, nothing ever out of range. On the hottest day I rode it was 107 outside. I Am gravitating toward the issue being temperature related, but need more testing.
Title: Re: SR/F hesitation stall issue
Post by: stevenh on September 13, 2020, 10:52:40 PM
This parser partially works with SR/F logs anyway. 

https://zero-motorcycle-community.github.io/browser-parse/zero-log-parser.html

It might be interesting to look at your MBB and BMS logs using this tool and search for any errors.

Steve
Title: Re: SR/F hesitation stall issue
Post by: Auriga on September 13, 2020, 11:56:35 PM
I don't mind looking at them if you want to post the unparsed logs, and the time one of these events occurred.

That doesn't sound like Zero's typical response, but any issues related to the drivetrain they could be hesitant to make recommendations without it being worked on by a dealer. You could try again, asking if they see any errors in your logs at x time. Maybe you got unlucky, I have heard of them doing this before. Not surprised if they still send you to a dealer, but if they do you could ask why they think you should go.

Title: Re: SR/F hesitation stall issue
Post by: Kaneda on September 15, 2020, 04:32:55 AM
I don’t know the first thing about posting a log. I have a very specific to
E frame today 1:43-1:50 that was so bad I thought I’d be walking. I also noticed ‘bumpiness’ while deceleration.

In the meantime I will email both parties (dealer and Zero)

I am also dropping the heat hypothesis today as it was 70-72 outside.
Title: Re: SR/F hesitation stall issue
Post by: Crissa on September 15, 2020, 04:37:40 AM
This seems like a real unique problem.

-Crissa
Title: Re: SR/F hesitation stall issue
Post by: Kaneda on September 15, 2020, 05:21:46 AM
I agree. I can’t find anything anywhere that sounds like what I’m going through. The closedown to it was a SR with a bad throttle. I promise I’ll post the resolve when I get there no matter how embarrassing or simple it may be.
Title: Re: SR/F hesitation stall issue
Post by: Kaneda on September 18, 2020, 01:31:15 AM
Small change, the issue became more prominent. This feels a lot like a bearing Issue that is loaded wrong / or now has a flat spot. The hesitation is the initial bind when accelerating from a stop. The bumpy sensation is likely the wheel or motor bucking. Goes away around 10mph. No noise yet-

Any other way I can test this further?

Was also told by dealer that there is no one at Zero factory right now, everyone is working from home, and the fires were about five miles away and they chose or needed to evacuate. Basically they are not responsive right now.
Title: Re: SR/F hesitation stall issue
Post by: Auriga on September 18, 2020, 02:09:16 AM
I think they may be stalling you.  Evacuation orders were lifted a week or so ago, and Zero support has remained available throughout. I'd call Zero Technical Support and take your bike to the dealer(or maybe a different dealer). They should be able to help and poke that dealer. They're the same people I call when I need Zero to discuss a repair.

Still sounds like a motor mechanical issue or an issue with motor synchronization. Not really anything to do outside the dealer
Title: Re: SR/F hesitation stall issue
Post by: Crissa on September 18, 2020, 03:07:00 AM
Some of us still aren't home, but nearly all the evacuation orders have ben lifted.  We've even had a couple days of vaguely-breathable air.

But they're still probably behind.

Did you managed to get your dealer to at least observe the issue or give yu a comparison?

-Crissa
Title: Re: SR/F hesitation stall issue
Post by: Shadow on September 18, 2020, 08:31:20 AM
It's good you can rule out ambient temperatures.

Does someone with a Gen3 SR/F or SR/S care to comment about taking off a wheel to check bearings? Have done it for a Gen2 DSR, it's super simple and should be part of periodic maintenance to inspect bearings anyways. That's a part you can easily replace.

Dealers are not obligated to provide a Zero loaner bike but with this kind of issue you'd be wise to spend your energy making that happen instead of (what amounts to) side-stepping the dealer to interact with Zero Motorcycles directly. Contrary to how you might typically handle problems of a technical nature when you are capable and able as a technical/mechanical minded person it's a small company and they don't have resources to interact with customers, that is the reality, and for better or for worse it's why they have an authorized dealer network. There is also not much incentive for dealers to play endless phone tag with Zero Motorcycles and fix bikes under warranty. Keep playing "spin the wheel" between dealers until you link up with a dealer willing to loan a bike and fix yours.
Title: Re: SR/F hesitation stall issue
Post by: Demoni on September 18, 2020, 10:31:37 AM
* I have next to no first hand experience with Zero motos or their drivetrain, reply is based on my EV experience *

Motors used in EV moto use position sensors to provide feedback to the controller about where the rotor is in reference to the energized coils of the stator.
This is used to calculate slip angle and adjust which coils are bring energized.

When this position is being reported incorrectly, stutters or inconsistent power delivery can be experienced at low speeds.
This issue can sound like damaged bearings.

If you are familiar with RC quads, planes or cars they use brushless motors that are sensorless, because these vehicles rarely see low rpm or high torque requirements it's not an issue.


Hardware issue would be my first guess but it's possibly a software one, seems there is some tuning (commissioning) that can be done.
On the physical side I would examine the plugs exiting your motor, it is possible one of the pins is not making good contact?
Also worth checking is your throttle assembly, I have seen one issue with the throttle unit used on the SR/F where the sensing magnet inside was broken in 2 pieces.