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Sherman S Disassembly Findings, Thoughts, and Ownership Log


MrMonoWheel

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6 hours ago, MrMonoWheel said:

Small update. I've been meaning to take photos of the screws that hold the battery housings to the suspension as the screws are too long and start threading into the main body of the suspension, but Jeremy from the veteran telegram group sent some pics of his today. 

IMG_20230110_171750_129.thumb.jpg.d79d2ad9d41d0122c7f2df36007815a9.jpgIMG_20230110_171758_731.thumb.jpg.5e593a30ef9aa80c0e0e2dbc0b0870d6.jpg

 

In this case the screw was bottoming out in the threads causing the head to shear off. I haven't had the heads of mine shear off but I did find metal shavings behind the suspension when disassembling, which came from the screws chewing their way into the aluminum shock body.

The stock screws are M6x14mm countersunk screws and I am replacing them with 12mm long stainless hardware.

https://a.co/d/ioULcCB

Don't know if it matters in each of the places you are replacing screws, and you already may be aware of this: most types of stainless steel have lower tensile strength than alloy steel. How much lower depends on the type and quality of stainless used. You mentioned you are purchasing screws off Amazon (quality?), I believe. This might be a time when an extra buck or two spent at McMaster-Carr would be worth it for peace of mind?

Also: steel screws into aluminum + salt air in SD, CA = galvanic corrosion?

$0.02

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49 minutes ago, MrMonoWheel said:

Today I received the side pads and upgraded seat, and let me tell you something. The amount these simple pads improved the riding character of the wheel blows my mind. First of all, seated riding went from being perched on top of an awkward shaped block of wood to sitting in a comfy chair. The shape and size of the seat is absolutely perfect and it really makes this feel like a comfortable cruiser when sitting down. It also gives you a sense of where you are sitting on the wheel for easy weight transfer and position changing.

The side pads made much more of a difference than I had expected. First of all, having my legs be able to rest against/grip a softer textured surface dramatically improves the comfort when riding. Furthermore, the fact that the pads extend front and back from the suspension make the entire top uniform in thickness which allows you to slide your legs along it and have much more control at slow speed. The wheel definitely should have come this way from the factory.

This is awesome to hear! My seat and side pads just arrived today and I'm keen to try them out. I just need the wheel to try them on.

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17 hours ago, UPONIT said:

Don't know if it matters in each of the places you are replacing screws, and you already may be aware of this: most types of stainless steel have lower tensile strength than alloy steel. How much lower depends on the type and quality of stainless used. You mentioned you are purchasing screws off Amazon (quality?), I believe. This might be a time when an extra buck or two spent at McMaster-Carr would be worth it for peace of mind?

Also: steel screws into aluminum + salt air in SD, CA = galvanic corrosion?

$0.02

From what I've read stainless is completely safe in aluminum. The point about the quality is valid, but I figure they can't be any worse than the stock ones seeing as someone sheared off a head without trying. 

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1 hour ago, MrMonoWheel said:

Today I received the side pads and upgraded seat, and let me tell you something. The amount these simple pads improved the riding character of the wheel blows my mind. First of all, seated riding went from being perched on top of an awkward shaped block of wood to sitting in a comfy chair. The shape and size of the seat is absolutely perfect and it really makes this feel like a comfortable cruiser when sitting down. It also gives you a sense of where you are sitting on the wheel for easy weight transfer and position changing.

The side pads made much more of a difference than I had expected. First of all, having my legs be able to rest against/grip a softer textured surface dramatically improves the comfort when riding. Furthermore, the fact that the pads extend front and back from the suspension make the entire top uniform in thickness which allows you to slide your legs along it and have much more control at slow speed. The wheel definitely should have come this way from the factory. 

The seat and pads come with pre installed Velcro (I was concerned it would all be adhesive), and they give you pre cut Velcro for the unicycle which is really nice for the trolley handle area.IMG_COM_20230111_1551000.thumb.jpg.046e1ee639ac26aab608203ebd2b3956.jpgIMG_COM_20230111_1551004.thumb.jpg.961336eabbea2a877d149f5fa48c8f51.jpgIMG_COM_20230111_1551002.thumb.jpg.0cf669ca0a54e7886efab675e3c2c927.jpgIMG_COM_20230111_1551003.thumb.jpg.a35455625dec5827e4b26f31abbd274c.jpg

 

IMG_COM_20230111_1551001.jpg

do you have a link to those pads?

thanks in advance.

steve

 

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13 hours ago, MrMonoWheel said:

Today I received the side pads and upgraded seat, and let me tell you something. The amount these simple pads improved the riding character of the wheel blows my mind. First of all, seated riding went from being perched on top of an awkward shaped block of wood to sitting in a comfy chair. The shape and size of the seat is absolutely perfect and it really makes this feel like a comfortable cruiser when sitting down. It also gives you a sense of where you are sitting on the wheel for easy weight transfer and position changing.

The side pads made much more of a difference than I had expected. First of all, having my legs be able to rest against/grip a softer textured surface dramatically improves the comfort when riding. Furthermore, the fact that the pads extend front and back from the suspension make the entire top uniform in thickness which allows you to slide your legs along it and have much more control at slow speed. The wheel definitely should have come this way from the factory. 

The seat and pads come with pre installed Velcro (I was concerned it would all be adhesive), and they give you pre cut Velcro for the unicycle which is really nice for the trolley handle area.IMG_COM_20230111_1551000.thumb.jpg.046e1ee639ac26aab608203ebd2b3956.jpgIMG_COM_20230111_1551004.thumb.jpg.961336eabbea2a877d149f5fa48c8f51.jpgIMG_COM_20230111_1551002.thumb.jpg.0cf669ca0a54e7886efab675e3c2c927.jpgIMG_COM_20230111_1551003.thumb.jpg.a35455625dec5827e4b26f31abbd274c.jpg

 

IMG_COM_20230111_1551001.jpg

does the seat pad affect trolly handle operation? do you have to unvelcro the seat for it to be lifted?

also, how do u like those power pads?

thanks,

steve

 

Edited by Steve Evans
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Apologies! I thought he was asking for the seat/upper pads link. Here's clarification.

 

Power pads:

https://a.aliexpress.com/_mqztizy

 

Upgraded seat and cushions:

https://a.aliexpress.com/_mNRgC4E

 

I use both and they work together very nice, gives the wheel a good look since it all matches.

In other news, today my stainless M6 hardware and the replacement stanchion clamp are arriving so I will be tearing it down once again to address these and a few other small changes. I plan to replace the tape covering the gaps in the mud guard support with plastic that's held in with silicone adhesive.

Edit: they arrived! GTKing sent two with screws as well, I'm well pleased. Now all I need it an hour of free time 😂

20230112_134555.thumb.jpg.1ca15c9fc26b8bcc2982e8aa59b61d8f.jpg

Edited by MrMonoWheel
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3 hours ago, MrMonoWheel said:

Nope! The seat allows the trolley handle to work perfectly, and you still have full view of the display. This is why I went this route instead of putting on a SurRon seat which was recommended to me multiple times.

I also love the power pads. For the price I don't think they can be beaten, although something like grizzla pads have more adjustability if you need it.

thanks a lot for being our guinea pig. ordered both power pads and seat/top pads.

steve

 

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Well I tore the wheel down and replaced the cracked part. The jb weld was halfway to breaking but it held that long! Here are some more notes about the wheel.

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!

The stainless screws I ordered are a perfect fit and they are 2mm shorter which lets them sit properly without threading into the shock body.

 

As far as the torque settings goes, I did some research and figured some settings to use. These are the numbers I went with, they are not from Leaperkim, use at your own risk.

- Axle nuts M6x21mm 12.9 grade, 140 in/lb

- Mudguard support to bracket M4x12mm, 30 in/lb

- Lower stanchion clamp M5x14mm, 70 in/lb

- Battery housing-to-suspension M6x12mm, 80 in/lb

- Battery housing-to-main M6x14mm, 100 in/lb

 

The rest of the M4x10mm screws used all over the wheel (motherboard cover, trim parts, etc) I just snug up by hand with an allen key. I applied new silicone to the motherboard cover and tightened it until I see the plastic snug up against the metal and the sealant squishes out. 

 

Hopefully I won't need to tear into the wheel for a while and can actually ride the thing 😁. I did notice that the clunking from the suspension is still there despite everything being set up properly. It occurs right when the suspension changes direction, I believe it's coming from inside one of the struts. 

 

Edit: one more thing. When reassembling the wheel it's extremely important to slowly tighten the bolts in a star/cross pattern for the suspension clamp/battery housing/etc. Furthermore, I left all the battery housing screws and upper battery-to-motherboard screws finger tight so I could stand the wheel up and compress the suspension a few times to get everything aligned. Then with the wheel standing I torqued everything in a star pattern to spec. My goal is for this method to remove any funkyness that could be imparted by torquing one side at a time with the wheel laying down.

Edited by MrMonoWheel
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10 minutes ago, MrMonoWheel said:

Well I tore the wheel down and replaced the cracked part. The jb weld was halfway to breaking but it held that long! Here are some more notes about the wheel.

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!

The stainless screws I ordered are a perfect fit and they are 2mm shorter which lets them sit properly without threading into the shock body.

 

As far as the torque settings goes, I did some research and figured some settings to use. These are the numbers I went with, they are not from Leaperkim, use at your own risk.

- Axle nuts M6x21mm 12.9 grade, 140 in/lb

- Mudguard support to bracket M4x12mm, 30 in/lb

- Lower stanchion clamp M5x14mm, 70 in/lb

- Battery housing-to-suspension M6x12mm, 100 in/lb

- Battery housing-to-main M6x14mm, 100 in/lb

 

The rest of the M4x10mm screws used all over the wheel (motherboard cover, trim parts, etc) I just snug up by hand with an allen key. I applied new silicone to the motherboard cover and tightened it until I see the plastic snug up against the metal and the sealant squishes out. 

 

Hopefully I won't need to tear into the wheel for a while and can actually ride the thing 😁. I did notice that the clunking from the suspension is still there despite everything being set up properly. It occurs right when the suspension changes direction, I believe it's coming from inside one of the struts. 

Those torque values seem a bit high, I was looking at Fastenal's generic table https://www.fastenal.com/content/feds/pdf/Torque of Metric Stainless Steel.pdf

Where did you find your recommendations?

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13 minutes ago, Tawpie said:

Those torque values seem a bit high, I was looking at Fastenal's generic table https://www.fastenal.com/content/feds/pdf/Torque of Metric Stainless Steel.pdf

Where did you find your recommendations?

I was looking at the same place but a different table because I didn't know what A2 stainless was 😂

Keep in mind the only stainless screws I use are the ones on the sides. The axle nuts are black coated 12.9 grade so the spec is correct for those. The rest of the screws I believe are zinc plated which also follow the correct spec.

metric_tighten_torques (1).pdf

 

Edited by MrMonoWheel
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16 hours ago, MrMonoWheel said:

😂

20230112_134555.thumb.jpg.1ca15c9fc26b8bcc2982e8aa59b61d8f.jpg

You received also washers and split lock washers with the screws. These washers were not included originally if I’m not wrong. Maybe these two levels of washers may help to not break this piece of metal or reduce the risk of too much torque on it. 

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30 minutes ago, rdouvi said:

Maybe these two levels of washers may help to not break this piece of metal or reduce the risk of too much torque on it. 

That is not the purpose of those flat or lock washers.

To prevent cracking, the part needs to carefully torque down evenly and not overly too tight.

The flat washer and lock washers will help the tightening torque be consistent and the screws don't loosen on it's own.

If you have enough experience, you can guage it by hand with a T-handle.

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3 hours ago, rdouvi said:

You received also washers and split lock washers with the screws. These washers were not included originally if I’m not wrong. Maybe these two levels of washers may help to not break this piece of metal or reduce the risk of too much torque on it. 

They were included originally.

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  • 3 weeks later...

Wanted to update the ownership log. Everything's been goin smooth since my last post. 200+ miles on the wheel without incident, until today. First issue: I rode to class as usual and turned the wheel off. After class when I turned the wheel on, I noticed I didn't hear any beep. I looked at the screen and it said "NO COM" with all the LED symbols turned on like it was in debug mode. I turned it off and back on and the entire wheel was reset. Odometer to zero, speed in KMH, tiltback at 17kmh, the whole 9 yards. Then while I was lifting it and spinning the wheel I realized the bearings sound like dry skateboard bearings, i.e. they are going bad. So looks like at the very least I will be contacting GTKing regarding the "firmware bug" and letting them know my bearings have gone bad, however I will be buying my own high quality bearings vs using whatever trash they are putting in batch 2.

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35 minutes ago, MrMonoWheel said:

For future bearing-changers, here's a link to the bearings I am going to be putting in the Sherman S.

https://www.ebay.com/itm/134344260913

Thanks for this. I'll revisit this post when my batch 2 bearings eventually fail, hopefully not anytime soon though. Now that I think of it, since i'm getting a new tire installed immediately upon arrival, I'm wondering if I should have Eevees replace the bearing with the SKF one from the get go.

Edited by Clem604
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1 hour ago, Clem604 said:

I'm wondering if I should have Eevees replace the bearing with the SKF one from the get go.

We haven't heard of many reports of bearings problems with Sherman-S out in the wild yet.

And boat trailers wheel bearings are often submerged in salt water when boats are launched.

Perhaps keep the stock bearings but replace the grease with marine grease.

People have reported good results with marine grease.

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15 hours ago, MrMonoWheel said:

For future bearing-changers, here's a link to the bearings I am going to be putting in the Sherman S.

https://www.ebay.com/itm/134344260913

McMaster-Carr has 4 choices in 6208-2rs bearings, ranging from $25 to $125 each (for stainless steel). Permanent-solid-polymer-lubed and sealed, $75/ea. Abec-3 Bearings made in USA, $75 each.

Options for added longevity/quality/precision...

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