Sherman-S 3600wh: 100V, 20", suspension, 97lb

[Planemo]

Interesting, and I see you picked up on my previous comments regarding how critical it is that the legs are parallel (and rigidly affixed to each other). Your findings on this do not make for good reading unfortunately.

Re the corrosion, again not good but alas not unique in the EUC world. These motors should have sealant (like a conformal coating) over everything immediately after production but I haven't seen many that have, possibly only the Ninebot Z series. Don't blame yourself, I am as confident as you are that you did nothing wrong and your stripdown post-wash kinda proves that. This is simply crap (read: cheap) assembly procedure from the motor factory. Surface corrosion on many of the parts I wouldn't really be bothered with as it won't affect much but when it's on the coil windings I get nervy - what will it be like in a couple of years...?

And the stator/magnet clearance is something else again - no way there should be any interference between the two.

Highly disappointing overall

 

 

[MrMonoWheel]

21 minutes ago, Planemo said:

Interesting, and I see you picked up on my previous comments regarding how critical it is that the legs are parallel (and rigidly affixed to each other). Your findings on this do not make for good reading unfortunately.

Re the corrosion, again not good but alas not unique in the EUC world. These motors should have sealant (like a conformal coating) over everything immediately after production but I haven't seen many that have, possibly only the Ninebot Z series. Don't blame yourself, I am as confident as you are that you did nothing wrong and your stripdown post-wash kinda proves that. This is simply crap (read: cheap) assembly procedure from the motor factory. Surface corrosion on many of the parts I wouldn't really be bothered with as it won't affect much but when it's on the coil windings I get nervy - what will it be like in a couple of years...?

And the stator/magnet clearance is something else again - no way there should be any interference between the two.

Highly disappointing overall

 

 

Yeah it definitely is disappointing, but I am hoping that making a bit of noise and sharing this information will just help quality improve everywhere for future wheels. Every bit counts. From day one I was saying how the suspension NEEDS to have a fixed upper mount that doesnt rely on the battery housing-to-motherboard joint. Even though its a tight fit, if its not perfect the suspension will suffer (as we can see).

My current plan is to fix what I can and run it. I am currently gluing down the hall board to the windings to hold it in place better. I cleaned all the corrosion from the inside of the motor covers using vinegar, however this discolors the magnesium alloy through a chemical reaction turning it very dark. However this is just a surface product and I soaked it with Kaboom brand cleaner and brushed it all out, looks good as new. For the bearings I am using the SKF bearings and they went in nicely. I decided instead of using silicone grease I will use Lucas brand marine grade bearing grease to put on the outside and under the rubber covers. I am hoping this grease will be more resilient to infiltration. Once everything is cleaned up and dry I will reassemble and see what I can do about the suspension. There's a good wheel in here, but a lot needs to be improved from the factory to make it come to fruition.

The current list of my issues:
- clunking suspension
- alignment issues causing excess stiction
- main board resets randomly
- bearings shot
- motor sits crooked in between battery housings
- stock screws for battery-housing to suspension are too long and chew up the metal 
- corrosion in motor housing and on windings
- signs of contact between stator and magnets
- hall sensor board very loosely affixed using silicone
- pedals came rusted
- pedals make contact with wheel removing paint
- lower stanchion clamp rubs inside of battery housing
- battery housing rubs side of plastic mud guard support 
 

Edited February 13, 2023 by MrMonoWheel

[Paul A]

Maybe GT King knowingly sold a used wheel that had corrosion, at the discounted price.

Unlikely Leaperkim would release a wheel with corrosion.

Possibly the beach ride did cause ingress of salt water.

The corrosion then caused the contact between magnets and stator.

 

Really need other owners to open and examine their wheels.

 

[Planemo]

37 minutes ago, Paul A said:

Maybe GT King knowingly sold a used wheel that had corrosion, at the discounted price.

Very much doubt it. I bet GT King had no idea.

37 minutes ago, Paul A said:

Unlikely Leaperkim would release a wheel with corrosion.

Like the seized pedal spindles you mean?

37 minutes ago, Paul A said:

Possibly the beach ride did cause ingress of salt water.

You did see that the OP pressure-washed the motor before stripping and there wasn't a single point of water ingress?

 

[MrMonoWheel]

43 minutes ago, Paul A said:

Maybe GT King knowingly sold a used wheel that had corrosion, at the discounted price.

Unlikely Leaperkim would release a wheel with corrosion.

Possibly the beach ride did cause ingress of salt water.

The corrosion then caused the contact between magnets and stator.

 

Really need other owners to open and examine their wheels.

 

I'd like to think they didn't do that, but who knows. As far as the beach ride, allow me to clarify. The beach riding I did was at most one mile total, and all of it was on hard packed dry sand. No standing water, no dampness, and after I pulled off the beach I inspected the wheel. Everything was completely dry, just a bit sandy. Think how your wheel would look after riding down the boardwalk with some sand on it. Now sure this dry sand probably had trace amounts of salt on it, but there's no way that dry salt on the sand particles could have liquified, moved past the silicone grease, through the bearings, and into the motor. And the motor covers had so much silicone that I almost couldn't get them off, so nothing came through there.

 

I don't want to seem like I'm defending myself, as you have seen I proudly display all my mistakes for the world to see. If I had ridden through 8 inches of standing salt water (like I did on my V11) I'd definitely say it.

 

 

Regarding the point of leaperkim releasing a wheel with corrosion, just remember:

 

 

I'm halfway kidding, but I'd never put it past any of them.

Edited February 13, 2023 by MrMonoWheel

[Paul A]

On 2/4/2023 at 4:45 PM, MrMonoWheel said:

........I have around 1800 miles on my V11. I took that on the beach for hundreds of those miles, riding through 1-6 inches of saltwater quite often...........Came home, rinsed it off with the hose, and its still going strong without any issues. 

 

On 2/4/2023 at 4:45 PM, MrMonoWheel said:

With the Sherman S I took it on a low tide beach ride with a total distance of about 1.5 miles. I rode on the hard packed sand about 20ft up from where the water line was.

 

Why the change in pattern of behaviour?

 

 

Edited February 13, 2023 by Paul A

[Freeforester]

Salty humid air ain’t that much of a friend…..

 

It’s a shame you didn’t open up the covers when you did your pre-ride, post delivery inspection, which would have given you more of an idea whether this was already a thing, or that it has resulted subsequently. 
 

 

Edited February 13, 2023 by Freeforester

[Paul A]

1 hour ago, Planemo said:

Like the seized pedal spindles you mean?

 

Would Leaperkim release a wheel that is so badly internally corroded?

[Freeforester]

16 minutes ago, Paul A said:

 

Would Leaperkim release a wheel that is so badly internally corroded?

Would it have been so badly internally corroded at assembly? Chinese QC standards apart, I think it would be fairly safe to suggest that this is indeed highly unlikely, which means that the corrosion can only have taken place thereafter; we don’t know how atmospheric humidity may or may not have affected the wheel in transit,  but I’m imagining that the wheel was taped-boxed up in a container, albeit in a salt air climate for the journey by sea. 
Whether other environmental factors should be taken into consideration in the period between 0-200 miles having been ridden is a bit of an open question, but generally speaking, humidity with iron and magnesium alloy in the mix (possibly with the ingress of salty humidity at that) may have some ‘bearing’ 🤔 on this discovery. Does anyone know how warm or otherwise the internal motor gets when in use? I do not, hence the question, but I do understand that where there is an atmospheric difference in temperature between surfaces, then, as one warm surface cools, there is a tendency for condensation to be formed (ask anyone who shoots rifles regularly while using a sound moderator).
 

Just trying to understand the process which has led to the surprising outcome here. Unlucky batch 1 issue, or something more concerning? 🤔

In either event, I’m now a bit minded to open my own S before riding, including the motor covers, just to see, but tbh I can also foresee the inherent danger of risking the corrosion becoming a self-fulfilling event if this were to be done on a day of high humidity, for example.

Im grateful for Mr Monowheel bringing this to the attention of the community, even though we have as yet to fully understand how it has come about. Living some 20 miles from the coast and not being inclined to cruise the beaches there, I’m nevertheless concerned that the corrosion has been found.

Edited February 13, 2023 by Freeforester

[Planemo]

1 hour ago, Paul A said:

Would Leaperkim release a wheel that is so badly internally corroded?

What makes you think that LK have any idea what the inside of a motor looks like when they don't produce it?

44 minutes ago, Freeforester said:

Would it have been so badly internally corroded at assembly?

Probably not, but air has moisture in it. Once sealed in it's not going anywhere. Unless you protect the inside surfaces with something, corrosion will result.

[Punxatawneyjoe]

10 hours ago, MrMonoWheel said:

So today I opened up my wheel to change the bearings

Thank you for all your honesty and info on this wheel. I am very sorry that you are having problems with your new wheel but thankful you are gracious enough to share your findings. The moisture inside the motor almost looks like it was assembled with super moist air inside of it and condensation has formed on everything inside. I think the stator rubbing on the magnets is just because of the bad bearings. it's unfortunate because the ss was emerging as the leader in suspension performance according to many people who have ridden it. I hope you get satisfaction from your supplier on these issues and i feel with your intimate knowledge of the unit you can come up with a solution on the suspension racking. I will be sure to do a tear down of the v13 after a few hundred miles as well. You have inspired me to share these findings with the community.

[Paul A]

1 minute ago, Planemo said:

What makes you think that LK have any idea what the inside of a motor looks like when they don't produce it?

 

Will need to wait and see if other owners start reporting similar corrosion in months to come.

Is it widespread and systemic?

Or particular to the one instance.

 

[Planemo]

18 minutes ago, Paul A said:

Will need to wait and see if other owners start reporting similar corrosion in months to come.

Is it widespread and systemic?

Or particular to the one instance.

I would suspect that one motor could vary wildly to another, depending on how humid the particular day is on which it was assembled.

The only real solution is to conformal coat everything that can fail through corrosion (or assemble in a controlled environment - far more expensive)

Products like this don't exist for fun:

You need to know about Epoxy Varnish For Motor Winding from the Epoxy Varnish For Motor Winding manufacturer, supplier, wholesaler, distributor, and factory (insulationmaterial.co)

[Paul A]

From the thread:  Sherman S Disassembly Findings Thoughts and Ownership Log

On 1/13/2023 at 7:13 PM, MrMonoWheel said:

The bearing covers were both caked with dirt from my riding but there was none under the seal due to the silicone grease. Seems to be doing a good job although I only have 100 miles on the wheel. If you ever clean and replace the silicone grease be sure to press the seal down to get any excess out, don't want that coming out during riding!

 

From this thread:  Sherman-S 3600wh 100V 20 Suspension 97lb

On 1/26/2023 at 7:42 PM, MrMonoWheel said:

I ordered the wheel as soon as I found a deal and have a batch 1. I've been putting the wheel through absolute hell (beaches, water, mud, steep trails, hard street riding, washing with a hose and compressed air) and it shows no signs of wear or issue. I'm past 200 miles now without a problem and I expect this trend to keep up.

______________________________________________

 

It might be that water has ingressed from all the hard riding.

Not necessarily from the beach ride alone.

 

 

 

 

[Paul A]

2 minutes ago, Planemo said:

depending on how humid the particular day is on which it was assembled.

 

Presumably there would have been other wheels/batch assembled on the same day as well.

May receive corrosion reports from other owners in the future if that is the cause.

Hopefully on this forum, or on another known EUC discussion site.

[Steve Evans]

just to provide another data point: i opened my wheel this weekend and it was in fine shape. no signs of corrosion/water ingress. this is at 360miles. i replaced my bearings b/c they were not correctly seated (knocking sound from motor).

steve

 

[Planemo]

It staggers me that they can't even push a bearing in without messing it up. You are confident that it wasnt the bearing itself that was the problem?

[JeremySPFF]

I have about 100 miles on my wheel and have not had an issues so far. Only street fwiw. I wanted to mention that when I got the wheel it had condensation on it. The metal was cold and stayed that way for a few hours collecting condensation, kind of like a cold glass of water. Not sure if that would cause rust or corrosion later.

[MrMonoWheel]

7 hours ago, Paul A said:

 

 

Why the change in pattern of behaviour?

 

 

The main reason is I got the v11 for free so honestly didn't care what happened to it, whereas I paid for the Sherman S and I also heard many stories about begode/veteran wheels and their lack of water resistance. I figured the v11 will be my thrashing wheel and the Sherman S will be for more civilized riding.

[MrMonoWheel]

4 hours ago, Paul A said:

From the thread:  Sherman S Disassembly Findings Thoughts and Ownership Log

The bearing covers were both caked with dirt from my riding but there was none under the seal due to the silicone grease. Seems to be doing a good job although I only have 100 miles on the wheel. If you ever clean and replace the silicone grease be sure to press the seal down to get any excess out, don't want that coming out during riding!

 

From this thread:  Sherman-S 3600wh 100V 20 Suspension 97lb

I ordered the wheel as soon as I found a deal and have a batch 1. I've been putting the wheel through absolute hell (beaches, water, mud, steep trails, hard street riding, washing with a hose and compressed air) and it shows no signs of wear or issue. I'm past 200 miles now without a problem and I expect this trend to keep up.

______________________________________________

 

It might be that water has ingressed from all the hard riding.

Not necessarily from the beach ride alone.

 

 

 

 

Just to clarify, as I might have been a bit overzealous when making that statement 😂 I had probably just gotten back from a ride and was amped up. I was really making that statement in reference to how others don't even think about offroading their wheel (or letting it go anywhere but street)

Total miles 200, beach miles 1, mud miles 0.25, dirt miles 10, puddles here and there.

Furthermore, before tearing it down it was a bit dusty so I washed the wheel and motor pretty aggressively with a pressure washer just to see how bad ingress is (as I could dry it all up anyway since I'm tearing it down). I didn't find a single speck of moisture anywhere inside the wheel or motor. So if it can withstand a 2000psi pressure washer at point blank range, I don't think mild moisture from any of my riding could possibly have worked it's way all the way into the motor past the bearings and silicone and then done this.

[Paul A]

10 minutes ago, MrMonoWheel said:

I figured the v11 will be my thrashing wheel and the Sherman S will be for more civilized riding.

??

 

On 1/26/2023 at 7:42 PM, MrMonoWheel said:

I ordered the wheel as soon as I found a deal and have a batch 1. I've been putting the wheel through absolute hell (beaches, water, mud, steep trails, hard street riding, washing with a hose and compressed air) and it shows no signs of wear or issue. I'm past 200 miles now without a problem and I expect this trend to keep up.

[Paul A]

Hope GT King replace the wheel.

[Steve Evans]

4 hours ago, Planemo said:

It staggers me that they can't even push a bearing in without messing it up. You are confident that it wasnt the bearing itself that was the problem?

no. only the sound that is typical of bearing seating issues. this is from vids i watched and ewheels/LK. but i did swap the bearings out too for better quality

[Paul g]

  Thank you guys for updates. I’m watching closely the Sherman S. From what I heard the Chinese bearings are not the highest quality so I’m not surprised some of them rust. The good news is they can be easily replaced with the proper stuff, the bad news is we shouldn’t be in the situation to do it. The one thing I’m most worried about is the leaky suspension. This is something that is very worrying with the S since there is no other producers for this form factor.

[MrMonoWheel]

5 hours ago, Paul A said:

??

 

I ordered the wheel as soon as I found a deal and have a batch 1. I've been putting the wheel through absolute hell (beaches, water, mud, steep trails, hard street riding, washing with a hose and compressed air) and it shows no signs of wear or issue. I'm past 200 miles now without a problem and I expect this trend to keep up.

 

5 hours ago, Paul A said:

Hope GT King replace the wheel.

They probably will. I understand some of my wordings seem to contradict eachother as they were each written at a different time, in a different mindset, under different conditions. What I can tell you is that the wheel was not abused, and the problems I am facing should not be occurring. I probably shouldn't have said I was putting the wheel through hell, as I really wasn't compared to what the V11 has gone through. I was probably just super amped in a good mood after a ride and was happy with the wheel.

 

1 hour ago, Paul g said:

  Thank you guys for updates. I’m watching closely the Sherman S. From what I heard the Chinese bearings are not the highest quality so I’m not surprised some of them rust. The good news is they can be easily replaced with the proper stuff, the bad news is we shouldn’t be in the situation to do it. The one thing I’m most worried about is the leaky suspension. This is something that is very worrying with the S since there is no other producers for this form factor.

I wouldn't be surprised if my suspension blows out as the next failure. With the suspension removed from the wheel I compress them and they do not feel normal. There is some weird sticky motion as though something inside is not right.