Sherman S Disassembly Findings, Thoughts, and Ownership Log

[MrMonoWheel]

Hey all! As you may know, I have been pretty active in the Sherman S speculation thread discussing the wheel and its possible issues. I now have a Sherman S that I purchased from GT King on AliExpress and received it 24 days after it shipped. For reference, I am on the west coast of the United States, so your shipping times may vary.

 

Starting off you must remove the trolley handle/seat assembly via 3 screws on each side of the display area. The middle chrome screws did not have threadlock but the black phillips screws did. 

 

Next is to remove all the screws holding on the motherboard housing cover. One question I have to ask is why in gods name did they use phillips head screws. They are way too easy to strip and they just look cheap. I will be replacing all of these with stainless allen key screws down the road. Regardless, once the cover is off I noticed it did in fact have a bead of gasket sealant around the lip.

Here is an overlook of the motherboard.

 

 

One thing to note is the generous use of black silicone adhesive holding everything in place. It is under the big capacitors as well as on each small silver capacitor despite these most likely not needing it. 

They also use it to keep all these screws from coming loose:

 

 

Something that is probably good but I found annoying was the application of silicone to the display connector, as I had to remove this connector to continue on my journey.

 

 

The charging ports both have black rubber gaskets:

 

 

A nice look at the Leaperkim branded connectors. Very beefy and well made:

 

 

The headlight module is very well made and has a nice weight to it. Feels high quality and is well sealed. All the screws and the beeper connector have black silicone to keep them in place:

 

 

The tail light on the other hand is a joke. Its made of plastic and weighs nothing, it feels like something from the dollar store that you would put on the back of a bicycle. Coming from a V11 with that bright motorcycle-esq tail light, this is comical. Also, the laser button worked once and then hasn't worked since, however I have no use for it as the lasers can be controlled via the headlight button on the dash:

 

 

Now is where things start getting interesting. This wheel is brand new and had less than 1km on it which I assume is from factory testing. Despite it being brand new, every pedal extension rod came heavily rusted to the point that the metal is pitted. I took a wire wheel to it and it barely helped, so I will be looking into chemical options. My guess is the pedals are made elsewhere and were stored poorly (or maybe even washed with a hose after machining) causing the rust. Leaperkim definitely should have caught this.

 

 

Here is a look at the ratchet mechanism. I haven't found it to serve a purpose and actually removed it before reassembling the wheel. The friction of the pedals keep them up just fine, and without the ratchet thing its nice and smooth. 

 

 

Here is the other side of the ratchet mechanism. I originally thought it was somehow molded or pressed into the battery housing but it is held in with a screw and easily removed:

 

 

As you might have noticed in that image, there is some wear already on the pedal hanger from where it makes contact with the pedal. This also occurs on the other pedal and hangers:

 

 

Furthermore, I noticed that when folding the pedals down they get very resistive near the bottom of their motion. Turns out its because of this protrusion that houses the ratchet assembly making contact with the bottom stanchion cover. This issue was only present on one side of the wheel, and can be prevented by dremeling away some of the pedal material. If you replace the pedals this problem wont exist:

 

 

Some people thought the wheel must have been soaked for the pedals to look so rusted, but the pedal pins themselves are spotless as is the rest of the wheel (rust wise). The pins are also identical which is good to know for reassembly:

 

 

I removed the lower stanchion cover thinking it was aesthetic/holding the two battery halves together, but it turns out the lower battery wires run through a plastic part that is screwed to the backside of this part. I was unable to free the battery wires from the plastic housing so this must be done after the battery housings are off the wheel. Order of operations and all that.

 

 

Before removing the housing I noticed this love mark someone left when their tool slipped:

 

 

 

Battery housing 1 is off, and the wheel looks super nice under there. Big beefy suspension, nice clean coated stanchions, big motor. Every screw holding the battery housing on had ample threadlock and were all torqued properly.

 

 

Heres my first look at the bearing. I was very pleased to see that they already applied silicone grease under the rubber cover to keep dust and water out.

 

 

Heres a closer look at the suspension. I have to say it is very well done.

 

 

Now time for some more fun stuff. If you look at the lower stanchion clamp you will see wear marks from where it is making contact with the battery housing. Keep in mind this has less than 10km on it at this point.

 

 

Here is another look at the wear and the result on the battery housing:

 

 

Now that I can see the way the motherboard housing is made and how the wheel goes together, I see it would have been very easy for them to add ridged upper stanchion mounts into the motherboard housing mold. If anything it would have made the wheel easier to work on as the suspension posts could be left on the wheel while everything else gets removed. Plus it would remove any doubt of structural integrity issues.

 

 

Here is a look at the axle and the motor wire. There was silicone sealing the motor wire to the axle and ample threadlock on all screws removed thus far.

 

 

 

In the previous image you might have noticed how dirty everything already was for just a few miles of slow street riding. This is largely due to the massive rectangular cutouts on the mudguard legs allowing everything in the wheel well to come into the suspension.

 

 

Im sure at some point someone will have a 3D printed solution that can be epoxied in, but for now I used gorilla tape on both sides. Note there are also gaps where the motor wire runs that should be covered with tape as well.

 

 

Heres a look at the silicone grease under the dust cover. I was pleased with the application of silicone grease, however I am not thrilled about how the motor wire enters the motor. There is a keyway cutout in the axle that the wire runs through, passes under the bearing and into the motor. Because of this its hard to get a proper seal with the silicone as you would have to apply the adhesive directly to the bearing face to really make a perfect seal:

 

 

Heres a look at the way the mudguard itself is mounted to the support structure. Nothing important here, just sharing.

 

 

Heres an overview of the mostly disassembled wheel. I left the motor wires connected and the motherboard in the housing as all those screws are secured with silicone/heatshrink and I didn't want to mess with them.

 

 

Notes about disassembly:

On my unit, every screw that I removed had ample threadlock and were properly torqued. The battery housings are a very snug fit and require a bit of love to remove. The battery housings are two halves held together by the lower cover with the "Leaperkim" logo in it, and there really is no reason to remove this. Fishing the battery cables out of the motherboard housing can be a bit difficult but they do fit, you just have to get the angle right.

 

Notes about reassembly

Reassembling the wheel is not the hardest thing in the world despite what a few youtubers have said, you just have to follow the order of operations.

First lay the mud guard support in place over the axle, install the axle-stanchion piece. Dont forget to install the small screws that hold the mud guard support in place.

Then put in the suspension damper and make sure its seated all the way down. Install the outer stanchion piece.

Next lay the motherboard housing in its position indicated by the indentations where the upper stanchion rests.

Before installing the battery housing, feed the wires through the motherboard housing. It is WAY easier to do this with the battery housings free to move down a few inches. There is about 5 extra inches of wire tucked away in the housing that you can pull out to make this easier.

Once the wire is fed through, install the battery housing onto the motherboard housing using the 4 stainless bolts. Repeat this process on the other side.

 

Easy mistakes to make

There are two mistakes that are pretty easy to make when reassembling this wheel. The first is in regard to the outer lower stanchion piece. When I was reinstalling mine I was using a very short handled tool to prevent over-torqueing, and yet the metal piece cracked. I was nowhere near the torque limit of the screw, so this is a piece that is easy to break. Be careful. The design of the part has the screw recessed into the metal essentially cutting the amount of support material in half. It cracked right along that line.

 

 

The second mistake which is 100% my fault is that the battery has two leads on the ground wires. The main cable and a tiny cable. It is very easy for this tiny cable to get pinched between the battery housing and the motherboard housing when reassembling. In my case it didn't cut through the wire, it only removed the insulation. Using electrical insulating gloves I unsoldered this wire from the connector and slid a piece of heatshrink over the exposed wire, then resoldered the connection. I don't recommend working with 100 volts DC unless you know what you are doing.

 

 

 

 

Overall thoughts on the wheel's build

This wheel is exceptionally easy to work on. I come from a background of working on all my own things (cars, motorcycles, appliances, house stuff, plumbing, electrical) so your mileage may vary, but compared to my V11 this thing is a treat. It is a very well built machine. It does have some issues that will most likely get ironed out over time, namely all the places that are making contact causing the surface finish to wear down.

The rusted pedal rods are unfortunate, but it seems that my wheel is one of few that have had this issue and I (like many others) will be replacing the pedals down the road anyway. The tail light on this wheel is a joke, feels cheap, and is very dim. I leave the lasers off because thats not really my thing. However the headlight build is exceptional even if the beam isnt as great as something like the V11/V13. Its more of a spotlight beam than a motorcycle grade headlight.

The suspension is very solid and the overall structure of the wheel makes it feel like a tank.

 

 

Overall thoughts on the wheel's usage

This wheel is exceptional to ride. When standing still it does have some weight to it, but even then its nothing that makes me regret buying it. If anything it makes the wheel feel like a vehicle more than a toy, especially knowing how much battery power I have under that shell. The suspension is something I have never experienced before, going off curbs, over bumps, and down stairs feels like you are riding a cloud. The rebound and compression adjustments actually serve a lot of purpose and can be set to any use case.

Now in regard to the ride of this wheel, its something I had to experience to understand. Despite the weight and 20 inch tire (even with a knobby), this wheel feels like it is on rails. Straight line riding is stable and smooth, I love the whirring the wheel gives off as you ride. The thing that really astonished me was the handling through turns. I was expecting this wheel to resist turning due to the gyroscopic forces and all that, but I actually think the higher center of gravity due to the batteries and suspension helps counter that force and lets the wheel effortlessly lean in turns. And its not all about the high speed.

Low speed maneuvers are easy which is something I did not expect. I can turn on a dime just like on my smaller V11 that I had ridden for a year. I did have to get used to using power pads, but it makes this wheel feel that much better.

Now for the pain points. The stock seat is not great, and the upper suspension covers dig into the sides of my calves causing some decent bruising. Now I am not a stranger to this and know it will go away in a months time as my body adapts to the wheel, but I also have the leaperkim seat and side pads coming from GTKing so that should help even more.

Overall I recommend this wheel to anyone looking for a well made comfortable machine, but if you are paying full retail I would suggest waiting a bit to see if they fix the little issues I had experienced. I purchased this wheel for around $3300 USD all said and done, and fully expected to run into issues seeing as its a first batch brand new wheel. However, the issues I found were trivial compared to what I expected. The core structure and functionality of this wheel is impeccable and I am extremely impressed.

Edited January 2, 2023 by MrMonoWheel

[MexicanBatman]

my cap cracked too

 

also the axle mounts have fore and aft flex (obviously not the axle mount that flexes but the stanchion) and have rubbed on the inside of the battery case, not just the cover but the actual axle mount or backing or whatever you want to call it

 

theres more, but i cbf typing...

 

its still best suspension wheel on the market, these minor issies will be easily rectified during production with no real need for new version wheels just refinement along the way

Edited January 2, 2023 by MexicanBatman

[MrMonoWheel]

15 minutes ago, MexicanBatman said:

my cap cracked too

 

also the axle mounts have fore and aft flex (obviously not the axle mount that flexes but the stanchion) and have rubbed on the inside of the battery case, not just the cover but the actual axle mount or backing or whatever you want to call it

 

theres more, but i cbf typing...

 

its still best suspension wheel on the market, these minor issies will be easily rectified during production with no real need for new version wheels just refinement along the way

Oh wow, glad to know I'm not the only one. How did you get a replacement?

[MexicanBatman]

reseller is ordering a new part

 

but i was careful to torque it too, but it cracked

 

i would like to see a better quality machined part as the cover rather than cast, but cant have it all

[InfiniteWheelie]

Congratulations on your new wheel, and thanks for sharing the breakdown.

The battery case is rubbing on the axle clamp because your weight when standing on the pedals flexes the battery case inward. The case is bolted much higher up, so anywhere below that point it's subject to flexing inward even though it's metal (shown in picture below). It's actually a good thing that it can rest/slide against the axle mount, since it prevents the metal battery case from flexing too far and cracking. If the two parts are of equal or similar hardness, the rubbing should do little other than polishing, nothing to worry about.

I'm still not a fan of the way it's constructed, I think the structural battery case is a bad idea. The battery cases, plus an upper clamp and pedal hangers, should all bolt directly to the upper suspension legs. The constant use of Philips screws is also beyond annoying at this point. The exposed wires joining the packs underneath seems totally unnecessary. The pedals are also ridiculous and gimmicky, but I would buy aftermarket regardless. Those are my critiques, but some of them can be remedied, and some can be lived with (no wheel is perfect).

 

 

 

Edited January 2, 2023 by InfiniteWheelie

[EMA]

grat infos thanks 

 

5 hours ago, MrMonoWheel said:

Now in regard to the ride of this wheel, its something I had to experience to understand. Despite the weight and 20 inch tire (even with a knobby), this wheel feels like it is on rails. Straight line riding is stable and smooth, I love the whirring the wheel gives off as you ride. The thing that really astonished me was the handling through turns. I was expecting this wheel to resist turning due to the gyroscopic forces and all that, but I actually think the higher center of gravity due to the batteries and suspension helps counter that force and lets the wheel effortlessly lean in turns. And its not all about the high speed.

Low speed maneuvers are easy which is something I did not expect. I can turn on a dime just like on my smaller V11 that I had ridden for a year. I did have to get used to using power pads, but it makes this wheel feel that much better.

this relates to the knobby with a wider rim, if you put a street tire on the wheel will stay more upright 

Edited January 2, 2023 by EMA

[MrMonoWheel]

I have sent an email to Leaperkim regarding all of these issues as well as contacted GTKing on Aliexpress. I'd be happy if they sent me a replacement part for the bracket that cracked as well as new pedal extensions for ones that arent heavily rusted. As far as the contact between the suspension and battery housing, as @InfiniteWheelie said this is a problem  of the battery housing flexing under load. As such there isn't anything they will be able to do for me (or any of us) since it would take a redesign to fix. Its possible that it will kinda wear itself in and stop being a problem, but its definitely something to keep an eye on over time.

[MrMonoWheel]

Update. GTKing got back to me saying he forwarded all this to Leaperkim and they will supply him with the parts I need to replace. Not sure on the timeframe as of yet, hopefully these things can be rush shipped so I can get on the wheel.

In the meantime, here are some better pictures of the cracked part and my analysis.

As you can see, the part cracked right across the line that has pressure being applied on it from the bolt. The metal also looks like cheap pot metal. 

 

In this image, you can see the additional recess the bolt goes into. This makes the actual usable material only a few mm thick, and there is no reason for this recess it just weakens the part and forms a place for failure to occur. I stacked some washers on the bolt to raise it up as though the recess didnt exist, and the head of the bolt still sat below the surface of the part and would not interfere with anything.

 

 

So in the meantime while I wait for the parts to be sent out, I am JB Welding the part together and will see what happens. The only sketchy part is if it fails I wont be able to see it, but the crack is clean and the surface is nice and rough so I think it will hold. Yes I am aware this is probably a very bad idea.

Edited January 3, 2023 by MrMonoWheel
Images weren't working

[techyiam]

2 hours ago, MrMonoWheel said:

I stacked some washers on the bolt to raise it up as though the recess didnt exist, and the head of the bolt still sat below the surface of the part and would not interfere with anything.

I don't think the washers are going to help. 

I think this is simply brittle fracture under tensile loading. The tensile stresses were too high for the particular UTS of the material, and the size of the cross-sectional area (approx. the fracture area) the tensile force was acting.

They can use a stronger material, larger cross-sectional area, or both.

If Wrongway and others were able to do all kinds of jumps and drop without cracking it, then it may be prudent to be cautious with the tightening torque. I think structurally, the required clamping force doesn't necessitate high tightening torque? 

Like you said, the part doesn't look particularly strong. 

I noticed when I work on electric wheels, I need to be extra careful with tightening torque than with mtb's, motorcycles or cars. 

 

 

 

 

[techyiam]

On 1/1/2023 at 9:14 PM, MrMonoWheel said:

Heres a look at the silicone grease under the dust cover.

Does this dust cover turn with the wheel, or stay stationary with the axle?

[MrMonoWheel]

1 hour ago, techyiam said:

I don't think the washers are going to help. 

I think this is simply brittle fracture under tensile loading. The tensile stresses were too high for the particular UTS of the material, and the size of the cross-sectional area (approx. the fracture area) the tensile force was acting.

They can use a stronger material, larger cross-sectional area, or both.

If Wrongway and others were able to do all kinds of jumps and drop without cracking it, then it may be prudent to be cautious with the tightening torque. I think structurally, the required clamping force doesn't necessitate high tightening torque? 

Like you said, the part doesn't look particularly strong. 

I noticed when I work on electric wheels, I need to be extra careful with tightening torque than with mtb's, motorcycles or cars. 

 

 

 

 

Maybe I misworded what I meant. I stacked some washers just to see how deep the screw head would sit had there not been a recess, and it still would not protrude out. Basically this shoes they could remove the recess and leave more material there for a stronger part. I agree that these wheels do need to be assembled more carefully as the materials aren't always the strongest.

 

Regarding the dust covers, they are free to rotate with the wheel or not. Nothing is holding them in place except friction.

[techyiam]

3 minutes ago, MrMonoWheel said:

Nothing is holding them in place except friction.

But based on what you have observed, when the wheel is moving were yours rotating or stationary? 

Thanks.

[MrMonoWheel]

12 hours ago, techyiam said:

But based on what you have observed, when the wheel is moving were yours rotating or stationary? 

Thanks.

When the wheel turned they rotated but not as fast as the wheel because of the friction on the axle. My guess is over time they will spin with as fast as the wheel.

Edit: Was wrong. The mudguard support and suspension mount apply pressure to the rubber seal holding it in place.

Edited January 3, 2023 by MrMonoWheel
Was wrong

[techyiam]

9 minutes ago, MrMonoWheel said:

When the wheel turned they rotated but not as fast as the wheel because of the friction on the axle. My guess is over time they will spin with as fast as the wheel.

Interesting compromise. Limited slip on both the hub surface and on the axle. They want the seal to seal around the axle but not overly tight.

I might have to try that on my Abrams. 

Thanks.

[UPONIT]

8 hours ago, MrMonoWheel said:

 

Did those pictures not come through for anyone else?

[meepmeepmayer]

59 minutes ago, UPONIT said:

Did those pictures not come through for anyone else?

Yep they don't work for me either.

@MrMonoWheel

[techyiam]

I can see all the pictures in this thread.

[Steve Evans]

1 hour ago, UPONIT said:

Did those pictures not come through for anyone else?

nope - i dont see them either. just a symbol indicating missing image.

[techyiam]

Maybe mine is coming from the cache since I looked at them early on.

[DragonFZ]

Thanks for the detail information. My Sherman S from eWheels ships some time this week. Ordered Kai Pads for it.

[MrMonoWheel]

5 hours ago, UPONIT said:

Did those pictures not come through for anyone else?

 

4 hours ago, Steve Evans said:

nope - i dont see them either. just a symbol indicating missing image.

Huh, that's strange. I see them as well as on a different device. Ill edit the posts and reupload them hopefully that fixes it. Are the ones in the first post loading?

[meepmeepmayer]

10 minutes ago, MrMonoWheel said:

Are the ones in the first post loading?

Yes. They always worked properly.

[Steve Evans]

32 minutes ago, meepmeepmayer said:

Yes. They always worked properly.

same. btw, just rechecked those images after page refresh - they are still absent. btw, its not the usual broken image icon, it looks like what i imagine might be a 'security fail' icon 

[MrMonoWheel]

2 hours ago, Steve Evans said:

same. btw, just rechecked those images after page refresh - they are still absent. btw, its not the usual broken image icon, it looks like what i imagine might be a 'security fail' icon 

 

2 hours ago, meepmeepmayer said:

Yes. They always worked properly.

I resized the images and re-uploaded them, it hopefully is working now.

 

12 hours ago, techyiam said:

But based on what you have observed, when the wheel is moving were yours rotating or stationary? 

Thanks.

I have to revise what I had said earlier. When I had spun the wheel I didn't have the plastic mudguard support and stanchion mount bolted to the axle. It seems now after having all that connected it puts some pressure on the rubber seal preventing it from turning, so it infact stays stationary.

[meepmeepmayer]

13 minutes ago, MrMonoWheel said:

I resized the images and re-uploaded them, it hopefully is working now.

Works now!