Sherman Max: missing motor axle sealant - all affected wheels require rework

[supercurio]

TLDR

Sherman Max motor has a hole at the top of its axle for the wires to get in.
There is no sealant to plug this hole, which is directly exposed to the motor and tire turning and facing up.
Dirt, sand, water is been found to get in the motor on a fairly new wheel. This will lead to noise, corrosion, and potential failure of the motor over time.

Issue discovery

Today I was helping a friend swap tire on his ~1.5 month old Sherman Max.
After removing the original tire, we noticed that there was a random grinding sound when turning the motor.
So we decided to open the motor to check. Everything looked good, I had no idea why there would be an issue.

 

Picture of the pedal hanger on the motor wire harness side. This sealant application looks good, right?

However after removing the other side cover, we started to see a bunch of sand all over the place, as you can see in the following pictures.

Sand on the magnets

Agglomerated sand on the other side cover with on the side of the motor wire harness

And we had no clue where this sand could come from: there was sealant around the wire harness, sealant between the rim and the side covers: no way for anything to come in. This is where we decided to remove the remaining pedal hanger, and that's what we saw:

Behind the pedal hanger, an chunk of fine sand and dirt around the bearing seal and axle hole

Pedal hanger removed, see where the sealant ends and how the dirt pools at the top of the axle.

To make things worse, the hole in the axle is facing upwards. This design makes this wire hole a funnel into the motor for any dirt, debit, sand, water, salt.. you get the point. All the things you don't want inside the motor can just fall in.

A few more pictures:

Bearing and cover from the wire harness side, you can the most dirt next to where the hole was. If you don't know what you're looking at, this was inside the motor.

same as close up 

Detailed view of the motor harness entrance point into the motor

State of both bearings

 

How to fix existing wheels

Most likely, everyone with a Sherman Max already ridden must:

1. Drop the motor from the inner shell
2. Remove the pedal hanger on the wire harness side to inspect how much dirt is around the hole. In order to remove this pedal hanger, you will need to cut the existing silicon, which might be useless.
3. Clean the area, by vacuuming if possible. Avoid using compressed air or anything which could push dirt into the bearing. Very little is enough to destroy the bearing.
4. Once the area is clean enough, fill any gap between the whole and wire harness with plenty of silicon. However, don't apply so much silicon that it would end up in the bearing or interacting with the bearing seal.
   I recommend using an alkoxy silicone which won't corrode metal to avoid damage to the bearing and motor.
5. Make sure that the hole is plugged by the sealant, from the axle up to the inner race of the bearing
6. Re-assemble while making sure that the sealant stays in place

Questions and observations

• As usual, the issue was already observed by Ecodrift during their Sherman Max teardown.
• The Abrams also lacks sealant in the same area, as seen on Ecodrift's Abrams teardown.
• It is possible that some wheels have enough silicon applied to seal the hole in the axle. However it is unlikely, since adding more silicon using the same method is likely to smear the whole area, bearing and bearing seal, making a huge mess instead of providing the result desired.
• Are some wheels siliconed correctly out of the factory? (No indication so far.)

Changes required during assembly

My best guess would be to apply silicon in the area which is exposed to the element directly. The current application is adding sealant on the clean side (inside of the wheel) and none on the dirty side (wheel well & tire) which does absolutely nothing to protect the motor from contaminants.

Silicon should still be applied where it is now in order to reduce stress on the harness due to shocks and vibrations.

Potential approach to explore for resellers before shipping wheels to customers

It might work to try to inject silicon into the desired hole without removing the motor from the shell, which would dramatically simplify the operation.
For this, you would need to:

1. Open the side panel
2. Break and remove the useless sealant around the wire harness
3. Push a small tube (almost like a needle) around the wire harness, in order to reach the motor axle hole. In terms of depth, go just a little beyond the beginning of the inner race of the bearing
4. Inject silicon there.
5. Repeat 3 times, for each remaining corner of the square hole.

Unfortunately, this approach won't work for wheels which have already been ridden since the whole in the axle must be clean for successful sealant application.

A downside of this approach is that it won't be possible to confirm visually if the application was successful or not, making it error prone.

What if you can't service your wheel / can't get it serviced

I would highly recommend to avoid riding the wheel altogether until this hole is sealed.
If you must, try at least to avoid any dirty, dusty or wet conditions.

I would encourage to ask your dealer about this, feel free to refer to this post as description.

To be clear: there isn't supposed to be an open hole into the motor. Every other electric motor is sealed.

I think it's a defect and not acceptable on a type of vehicle used outdoors and will lead to all sort of potentially issues issues after winter, in wet locations and for off-road riders. In terms of safety I don't want to think about what will happen when salt water gets sprayed on the hall sensor.

Edited July 30, 2022 by supercurio
added TLDR

[Paradox]

@Jason McNeil  Please respond to this post as I have a Max on pre-order with ewheels. 

[techyiam]

On 7/29/2022 at 7:21 PM, supercurio said:

Pedal hanger removed, see where the sealant ends and how the dirt pools at the top of the axle.

To make things worse, the hole in the axle is facing upwards (needs confirmation). This design makes this wire hole a funnel into the motor for any dirt, debit, sand, water, salt.. you get the point.

That means the sealant wasn't applied, and the axle sealed before the hanger was bolted on. That wheel doesn't even have the lowest particles and water ingress protection. Far cry from what Inmotion is claiming for their V13 wheel.

 

On 7/29/2022 at 7:21 PM, supercurio said:

Make sure that the hole is plugged by the sealant, from the axle up to the inner race of the bearing

And if any silicone get on the seal, it must be removed, since the inner race stays stationary with the hanger, but the seal rotates.

Edited July 31, 2022 by techyiam

[techyiam]

@supercurio

In some of the photos, sand was shown to have gotten past the bearing seals and mixed in with the grease. Did the rider ride in wet sand? If not, did he ride in deep sand?

[supercurio]

7 hours ago, Paradox said:

@Jason McNeil  Please respond to this post as I have a Max on pre-order with ewheels. 

Yes let's shoot an email to Jason to alert him of the issue. eWheels has the resources to check a bunch of wheels quickly, and single-handedly make Leaperkim fix this unprecedented oversight before any other Sherman Max leaves the factory.

 

6 hours ago, techyiam said:

That means the sealant wasn't applied, and the axle sealed before the hanger was bolted on. That wheel doesn't even the lowest particles and water ingress protection. Far cry from what Inmotion is claiming for their V13 wheel.

And if any silicone get on the seal, it must be removed, since the inner race stays stationary with the hanger, but the seal rotates.

Exactly, no protection at all, with this Leaperkim specific design.
On a traditional axle, sealant missing wouldn't be as bad since the axle hole ends inside the wheel - which already offers a good amount of protection. Here instead the hole is open to where it is exposed the most near the tire, making the problem a lot worse.

The problem is compounded by the fact the hole is facing up so things can just fall in with to gravity (that part needs to be confirmed)

Sealant application might be a little tricky: pushing just the right amount without it getting into the bearing seal on either side. Then the wire harness will wiggle around a little when fitting the pedal hanger which could push the sealant where undesired. Tricky but certainly feasible.
Maybe that's why they're not doing it in the factory? Or they didn't think of it and that would be mind-boggling; going to the extent of designing a custom large axle to fit thicker wires, and not thinking about the most basic way how to protect it from dirt, not catching the issue during the product testing either.

Isolated case or 100% of the wheels missing sealant here?
We don't know yet, and it's some amount of work to be able to, a few hours of time and requiring an impact wrench to remove the 6 big screws.

3 hours ago, techyiam said:

In some of the photos, sand was shown to have gotten past the bearing seals and mixed in with the grease. Did the rider ride in wet sand? If not, did he ride in deep sand?

Yes my friend crossed a sandy beach twice when we were on a big group ride. @Rawnei was there as well so maybe there's sand in his Max motor too. Sand was dry.
My friend encountered a bit of rain since which might be why the sand particles pooled as seen.

[Paradox]

@supercurio did you inspect your Max for the same conditions?  I too am wondering if this is isolated or common among the Max wheels.

[supercurio]

4 hours ago, Paradox said:

@supercurio did you inspect your Max for the same conditions?  I too am wondering if this is isolated or common among the Max wheels.

I didn't inspect mine yet but plan to do so sooner than later. I won't ride it until then.
Next week @Rawnei and I will take a look at his Sherman Max, from a different batch and seller.

[Planemo]

Madness that the motor wires enter from the top. All ebike hub motors have it looping up and under, like usual drip-loop convention for household exterior wires such as phone lines, domestic power supplies and sat cables.

Its the easiest way to reliably keep water out  let alone dirt etc.

[supercurio]

@Planemo I was not sure but looking again at this picture, there is no doubt that the wire harness enters via a hole situated at the top of the axle.

Here, the wire harness:

• comes from the top (mainboard)
• enters above the 3 big screws
• EUC Upgrade video (timestamp) shows the full arrangement.
• wire harness goes into the motor via the hole in the axle above the 3 big screws

That's why there's also an excess of dirt accumulating up there, and a really dirty bearing.
By the way the bearing seals don't seem to be rotating.

I guess the fact that the wires enter from the top instead of bottom would not really be an issue if the hole was packed with sealant.

Edited July 30, 2022 by supercurio

[Lenneth_WFXZ]

I have close to 400 miles on my Max. Already have the battery low tipping over issue...really hope I don't have this one too- emailed back but havent heard anything from @Jason McNeil I'm a noob and thought i was getting pushback but the menu was just still in KM LOLOL all well - tip over thing is real af...hope this one isn't...as..common

Damn ittttt

[Lenneth_WFXZ]

Just now, Lenneth_WFXZ said:

I have close to 400 miles on my Max. Already have the battery low tipping over issue...really hope I don't have this one too- emailed back but havent heard anything from @Jason McNeil I'm a noob and thought i was getting pushback but the menu was just still in KM LOLOL all well - tip over thing is real af...hope this one isn't...as..common

Damn ittttt

BTW

Sherman Max still fun af wheel- took a health 30 miles in my yard to even stand and move around on it. Zero regrets as long as I dont have to send the wheel back. L O L

[techyiam]

45 minutes ago, Lenneth_WFXZ said:

took a health 30 miles in my yard to even stand and move around on it.

Wow, you learned on a Sherman Max. You must be a very determined learner.

Since that is all you know, when you try lighter wheels, you will complain that those wheels are to tippy, unstable.

I guess the plus side is that there are not many reasons for you to upgrade. But that won't stop you from wanting. 🙂

[supercurio]

56 minutes ago, Lenneth_WFXZ said:

Zero regrets as long as I dont have to send the wheel back. L O L

Hey, @Lenneth_WFXZ.

For now I'd say it's a phase of investigation: how many wheels are affected? We don't know yet.
So at the moment we hope for dealers, service centers and mechanics-oriented owners to check their wheels which should give a good idea.

[Lenneth_WFXZ]

11 minutes ago, techyiam said:

Wow, you learned on a Sherman Max. You must be a very determined learner.

Since that is all you know, when you try lighter wheels, you will complain that those wheels are to tippy, unstable.

I guess the plus side is that there are not many reasons for you to upgrade. But that won't stop you from wanting. 🙂

I thought I was getting pushback at 20mph because of the battery low issue- when I found my imperial settings werent applying and my tilt back was really in km LOL

You right, I just past 20mph now - 60mile rides, i couldn't imagine having a lighter weaker wheel...other than the mten3 lol. That little bugger looks like fun.

It just required patience to learn. Best advice - avoid assists like wall and trees etc. What point of riding if you can't even mount. Once you mount- the rest comes with persistence and practice. Sherman Max best beginner wheel. I'll die on that hill XD

[Lenneth_WFXZ]

12 minutes ago, supercurio said:

Hey, @Lenneth_WFXZ.

For now I'd say it's a phase of investigation: how many wheels are affected? We don't know yet.
So at the moment we hope for dealers, service centers and mechanics-oriented owners to check their wheels which should give a good idea.

Honestly dont want to open my wheel just yet- once Jason advises me what he wants to do about the low battery issue, Ill go from there. Work has been draining on me- no EUC is terrifying. 

 

[techyiam]

31 minutes ago, Lenneth_WFXZ said:

You right, I just past 20mph now - 60mile rides, i couldn't imagine having a lighter weaker wheel...other than the mten3 lol. That little bugger looks like fun.

It just required patience to learn. Best advice - avoid assists like wall and trees etc. What point of riding if you can't even mount. Once you mount- the rest comes with persistence and practice. Sherman Max best beginner wheel. I'll die on that hill XD

You can free mount already?

Curious, are you using power pads or spike pedals?

[WattsWheelhouse]

I'm two days into learning on a sherman max as my first euc as well, quite the fun journey so far! No pads or aftermarket pedals for me yet, though my powerlifter/sprinter calves are begging me to get wider pedals. 

But with 25 years experience as an auto technician, I suppose I should pull it apart to inspect. Any good places to find a manual/instructions/tutorial? 

Edited July 31, 2022 by Racer13X

[supercurio]

@Racer13X good idea! Definitely check before it could get bad.

You can follow Ecodrift teardown steps

And these videos as inspiration:

The Sherman teardown / tire change will be similar to a point as well if you'd like to find even more info.

[Lenneth_WFXZ]

29 minutes ago, techyiam said:

You can free mount already?

Curious, are you using power pads or spike pedals?

Yup yup, its my only transport so gotta be able to.

Started stock pedals with power pads mostly protection of the wheel, i barely use them I noticed a few days ago. Sometimes for fun hard breaking?
Stock pedals on a Max are utter trash. Legit the biggest flaw. ESPECIALLY a beginner whos gonna tip the wheel a bit. She holds it though otherwise. 

The pedals both split open and put on spike pedals since I knew I wasn't going to scratch them up. 

Once you get over that initial mountain, things come easier. My mistake to limit my speed with tilt back set low speeds let me focus on control. Still not perfect, far from it- got a horrible twist to the left because of weak hips and lotta time on the OW. 

[WattsWheelhouse]

17 minutes ago, supercurio said:

@Racer13X good idea! Definitely check before it could get bad.

You can follow Ecodrift teardown steps

And these videos as inspiration:

The Sherman teardown / tire change will be similar to a point as well if you'd like to find even more info.

Perfect! I should order some fun bits to put on during the process.. 

[supercurio]

5 minutes ago, Racer13X said:

Perfect! I should order some fun bits to put on during the process.. 

If you don't already have, I may suggest alkoxy silicon to use as sealant, since it's non-corrosive to metals.
I'll be in direct contact with the axle (painted) and bearing (not painted)

That would be ideal, although I'm sure there are a few fine alternatives. Looking forward to hear about what you find and your experience!

Edited July 31, 2022 by supercurio

[techyiam]

1 hour ago, Lenneth_WFXZ said:

got a horrible twist to the left because of weak hips and lotta time on the OW. 

When you say, "horrible twist to the left", under what conditions? 

OW world  to EUC world, how are you liking it? How would you compare them?

[supercurio]

@techyiam @Lenneth_WFXZ and mods, might be best to continue/move the separate discussion on the general Sherman Max topic, thanks 🙏

Edited July 31, 2022 by supercurio

[fryman]

On 7/29/2022 at 9:21 PM, supercurio said:

TLDR

Sherman Max motor has a hole at the top of its axle for the wires to get in.
There is no sealant to plug this hole, which is directly exposed to the motor and tire turning and facing up.
Dirt, sand, water is been found to get in the motor on a fairly new wheel. This will lead to noise, corrosion, and potential failure of the motor over time.

Issue discovery

Today I was helping a friend swap tire on his ~1.5 month old Sherman Max.
After removing the original tire, we noticed that there was a random grinding sound when turning the motor.
So we decided to open the motor to check. Everything looked good, I had no idea why there would be an issue.

 

Picture of the pedal hanger on the motor wire harness side. This sealant application looks good, right?

However after removing the other side cover, we started to see a bunch of sand all over the place, as you can see in the following pictures.

Sand on the magnets

Agglomerated sand on the other side cover with on the side of the motor wire harness

And we had no clue where this sand could come from: there was sealant around the wire harness, sealant between the rim and the side covers: no way for anything to come in. This is where we decided to remove the remaining pedal hanger, and that's what we saw:

Behind the pedal hanger, an chunk of fine sand and dirt around the bearing seal and axle hole

Pedal hanger removed, see where the sealant ends and how the dirt pools at the top of the axle.

To make things worse, the hole in the axle is facing upwards. This design makes this wire hole a funnel into the motor for any dirt, debit, sand, water, salt.. you get the point. All the things you don't want inside the motor can just fall in.

A few more pictures:

Bearing and cover from the wire harness side, you can the most dirt next to where the hole was. If you don't know what you're looking at, this was inside the motor.

same as close up 

Detailed view of the motor harness entrance point into the motor

State of both bearings

 

How to fix existing wheels

Most likely, everyone with a Sherman Max already ridden must:

1. Drop the motor from the inner shell
2. Remove the pedal hanger on the wire harness side to inspect how much dirt is around the hole. In order to remove this pedal hanger, you will need to cut the existing silicon, which might be useless.
3. Clean the area, by vacuuming if possible. Avoid using compressed air or anything which could push dirt into the bearing. Very little is enough to destroy the bearing.
4. Once the area is clean enough, fill any gap between the whole and wire harness with plenty of silicon. However, don't apply so much silicon that it would end up in the bearing or interacting with the bearing seal.
   I recommend using an alkoxy silicone which won't corrode metal to avoid damage to the bearing and motor.
5. Make sure that the hole is plugged by the sealant, from the axle up to the inner race of the bearing
6. Re-assemble while making sure that the sealant stays in place

Questions and observations

• As usual, the issue was already observed by Ecodrift during their Sherman Max teardown.
• The Abrams also lacks sealant in the same area, as seen on Ecodrift's Abrams teardown.
• It is possible that some wheels have enough silicon applied to seal the hole in the axle. However it is unlikely, since adding more silicon using the same method is likely to smear the whole area, bearing and bearing seal, making a huge mess instead of providing the result desired.
• Are some wheels siliconed correctly out of the factory? (No indication so far.)

Changes required during assembly

My best guess would be to apply silicon in the area which is exposed to the element directly. The current application is adding sealant on the clean side (inside of the wheel) and none on the dirty side (wheel well & tire) which does absolutely nothing to protect the motor from contaminants.

Silicon should still be applied where it is now in order to reduce stress on the harness due to shocks and vibrations.

Potential approach to explore for resellers before shipping wheels to customers

It might work to try to inject silicon into the desired hole without removing the motor from the shell, which would dramatically simplify the operation.
For this, you would need to:

1. Open the side panel
2. Break and remove the useless sealant around the wire harness
3. Push a small tube (almost like a needle) around the wire harness, in order to reach the motor axle hole. In terms of depth, go just a little beyond the beginning of the inner race of the bearing
4. Inject silicon there.
5. Repeat 3 times, for each remaining corner of the square hole.

Unfortunately, this approach won't work for wheels which have already been ridden since the whole in the axle must be clean for successful sealant application.

A downside of this approach is that it won't be possible to confirm visually if the application was successful or not, making it error prone.

What if you can't service your wheel / can't get it serviced

I would highly recommend to avoid riding the wheel altogether until this hole is sealed.
If you must, try at least to avoid any dirty, dusty or wet conditions.

I would encourage to ask your dealer about this, feel free to refer to this post as description.

To be clear: there isn't supposed to be an open hole into the motor. Every other electric motor is sealed.

I think it's a defect and not acceptable on a type of vehicle used outdoors and will lead to all sort of potentially issues issues after winter, in wet locations and for off-road riders. In terms of safety I don't want to think about what will happen when salt water gets sprayed on the hall sensor.

To make sure sealant is done properly, I think the pedal hanger will need to be removed and reinstalled after sealant is dry.

[supercurio]

Got a quick reply from @Linnea Veteran!

Quote

As for Sherman max motor problem, we had fixed this problem half a year ago

The motor you've seen in the pictures has the motor serial of 220101XX
Another local rider has the motor serial 220100XX, so it likely has the axle hole open as well.

My own unit has the serial 220500XX, I might be in luck.

I asked just now Linnea at what exact date / serial number they implemented the fix, for 100% of the production. Although to be really confident, I would like to see this sealant application after the fix to confirm how well it turned out.

 

For now, we can assume that 20220101XX and all older motors have no axle sealant.
So what's your Max serial number? Check now!

Edited August 1, 2022 by supercurio