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

[Planemo]

4 minutes ago, Unicycle Santa said:

or the oil isnt able to easily reach the upper bushings

This has always been the engineering issue with upside down forks. Obviously it can be done given MC's have been using them for years but it's no trivial matter.

[onkeldanuel]

Wait for batch 3 at least for revising any upcoming suspension problem. First try on fork type suspension on euc will probably lead to some serious design/Implementation questions and most likely improvements in the next batches i guess

[Mango]

 

[Paul A]

Разбираем Veteran Sherman-S (teardown)

EcoDrift-Life

2.36K subscribers

Nov 16, 2022

 

 

 

[MrMonoWheel]

9 hours ago, Planemo said:

Not having the two legs rigidly tied together could well lead to excessive stiction. The tolerances between the internal bushings and stanchions should be virtually zero and therefore any flex anywhere along the leg is unwanted.

You can see initial stiction on impact on these slo-mo MTB vids. Granted the legs are a lot shorter on the Sherman but it's surprising just how much flex is found even in big name suspension brands, and this is even with the legs being tied together at 3 points.

 

Yep that's an excellent point. Even if there's a microscopic amount of misalignment or flex it will cause this. Seeing as the forks are "connected" through 8 screws across 3 physical sections I don't doubt it.

 

[360rumors]

Is there some reason fastace didn’t think it was necessary to advise leaperkim to add a rigid brace between the forks? Fastace presumably knows what they are doing…?

[MrMonoWheel]

16 minutes ago, 360rumors said:

Is there some reason fastace didn’t think it was necessary to advise leaperkim to add a rigid brace between the forks? Fastace presumably knows what they are doing…?

I would hope so, but I have also seen more significant things get overlooked. 

[RagingGrandpa]

"Upper bushing durability" is something we'll only be able to know after production wheels have been in service for 1,000 miles or more...

Storing the EUC on its side (or ideally: inverted) may improve bush wear also.
As if we needed one more thing to obsess over  

 

Edited November 16, 2022 by RagingGrandpa

[wstuart]

4 hours ago, Unicycle Santa said:

Yep that's an excellent point. Even if there's a microscopic amount of misalignment or flex it will cause this. Seeing as the forks are "connected" through 8 screws across 3 physical sections I don't doubt it.

 

Two of my other hobbies are radio contol helicopters and racing radio control cars.  In both those hobbies the person building car or helicopter has to check for and eliminate "tweak" which is a super minscule amount of twisting mis-allighnemnt between the two carbon fiber frames and the metal bits holding them together.  The cars and helicopters must be assembled in a certain way on a super flat surface to ensure "tweak" is not introduced during assembly.  You must then periodically check the frame for tweak by seeing if all the shafts and belts spin freely.  The smallest amount of twisting in the frame (naked to the eye) can bind up shafts, belts and suspensions.

The way the Sherman S goes together seems like "tweak" could be an issue.  I wonder if Adam just loosened the screws, layed the wheel on a flat surface, and then retightened the screws, if the binding in the suspension would change - maybe for the better, maybe worse?

 

[InfiniteWheelie]

With the forces involved and the way it’s bolted together, I’m pretty sure there’s much more than a minuscule amount of flex happening.

This could explain worn suspension and bolts coming loose constantly.

Edited November 16, 2022 by InfiniteWheelie

[RagingGrandpa]

Tweak from crashes seems less likely on Sherm-S than the competitors, such as the thin single pair of slide tubes Begod is using everywhere.

But right, tweak from rough riding (without crashing) might be encouraged in designs like Sherm-S where the shocks are different on each side, due to unequal forces. 

I like @wstuart's idea: loosen the body fasteners to prove it. Ezpz.


FWIW I think the tire change will be easy: 
Remove the left-side battery and left-side shock, then unscrew and separate the fender halves above the tire. That's all. Motor and controller can remain connected and undisturbed.

 

Edited November 16, 2022 by RagingGrandpa

[Kekafuch]

How much will replacement forks cost? Generally how much is it to rebuild forks? 
 

 

[Tawpie]

2 hours ago, wstuart said:

The cars and helicopters must be assembled in a certain way on a super flat surface to ensure "tweak" is not introduced during assembly

ugh. I certainly hope that fixturing isn't required for 'proper' assembly. I've had experience with assemblies that did require fixtures to get them together properly.. they were labeled "no user serviceable parts inside" cuz without the fixture it wouldn't go back together properly.

[fbhb]

11 hours ago, RagingGrandpa said:

FWIW I think the tire change will be easy: 
Remove the left-side battery and left-side shock, then unscrew and separate the fender halves above the tire. That's all. Motor and controller can remain connected and undisturbed.

Yep, that is the way Leaperkim have already stated the tyre change can be carried out backed up by this video Linnea Lin sent to one of the regular posters (The Electric Monkey) on Telegram:

 

EDIT #1:  the version of the video posted below seemingly got cut down to ONLY 3:00 minutes long by flickr, whereas the original was 11:41 long!

Here is a link to the original post on Telegram that hopefully works OK:  https://t.me/veteranUS/4816EDIT #2: Another Full-length version was posted on YouTube:

 

 

Edited November 17, 2022 by fbhb

[That Guy]

25 minutes ago, fbhb said:

Yep, that is the way Leaperkim have already stated the tyre change can be carried out backed up by this video Linnea Lin sent to one of the regular posters (The Electric Monkey) on Telegram:

 

I wonder whether you really have to disconnect the battery from the controller module or just move it out/up/aside (securely) while the tire is replaced? 

[wstuart]

5 hours ago, Tawpie said:

ugh. I certainly hope that fixturing isn't required for 'proper' assembly. I've had experience with assemblies that did require fixtures to get them together properly.. they were labeled "no user serviceable parts inside" cuz without the fixture it wouldn't go back together properly.

Yeah that would suck....maybe it could be a simple process that gets 90% of the way there.

 

I would imagine that setting the bottom of the Sheran S pedals on 2 totally flat/level stacks of bricks could be a make-shift fixture.  Then loosen and carefully tighten the 8 screws on each side (cross pattern, progresivly torquing each screw).  Leaperkim could probably figure out which order to torque the screws to eliminate tweak.

 

Edited November 17, 2022 by wstuart

[Tawpie]

4 hours ago, fbhb said:

Yep, that is the way Leaperkim have already stated the tyre change can be carried out backed up by this video Linnea Lin sent to one of the regular posters (The Electric Monkey) on Telegram:

 

darn. It's only 3:00 long for me... didn't even get the side panel off. I did pay the internet bill, I promise.

Edited November 17, 2022 by Tawpie

[fbhb]

52 minutes ago, Tawpie said:

darn. It's only 3:00 long for me... didn't even get the side panel off. I did pay the internet bill, I promise.

Not sure what happened with it getting cut down to Only 3:00 minutes long (should be 11:41), will try to fix it and re-upload to the OP.

In the meantime, this link to the original Telegram post should work OK:

https://t.me/veteranUS/48168

Edited November 17, 2022 by fbhb

[techyiam]

Youtuber Alexutlang felt that his stock Sherman-S is less stable at high speeds than the OG Sherman, Sherman Max, and especially 22" and 24" wheels. 

His opinions are stated in the comment section.

 

[Tasku]

3 hours ago, techyiam said:

Youtuber Alexutlang felt that his stock Sherman-S is less stable at high speeds than the OG Sherman, Sherman Max, and especially 22" and 24" wheels. 

I feel like everytime i get new wheel it sucks. It just is not exactly that what I gotten used to riding my 20 000 km already with the thing I got used to. But you know after 1000km my Sherman OG was way better than the rest. It sure did took some time for me to get in to the "zone". I am actually more surprised how most reviewers get in to that zone soo quick. But when you ride that one device and get all in tune with it, it is hard charm to break immediately.
 

[360rumors]

6 hours ago, techyiam said:

Youtuber Alexutlang felt that his stock Sherman-S is less stable at high speeds than the OG Sherman, Sherman Max, and especially 22" and 24" wheels. 

His opinions are stated in the comment section.

 

He has since changed his opinion and told me it was “the best all around wheel for me”. 
See comments if you are part of this fb group

https://www.facebook.com/groups/753593188713546/permalink/1343291596410366/?mibextid=W9rl1R

[techyiam]

1 hour ago, 360rumors said:

He has since changed his opinion and told me it was “the best all around wheel for me”. 
See comments if you are part of this fb group

https://www.facebook.com/groups/753593188713546/permalink/1343291596410366/?mibextid=W9rl1R

It sounded like he is having to adapt to the new suspension wheel architecture, and a 20" wheel, since he has been riding mostly on his 24" Monster Pro for the past year. But then again, maybe 20" wheels in general won't be as stable as 22" wheels.

Being a speed junkie that he is, in the same paragraph, he was asking for an Abrams S with the same suspension design (no separate spring and damper legs, please), more battery capacity, and a top speed higher than the Master Pro. So, it sounded like he would prefer a 22" suspension wheel from Leaper Kim. Odd that he did not mention the V12.

Edited November 17, 2022 by techyiam

[BKW]

Alexutlang seems to be a rider that desires speed over most. I don't think the sherman-s is a wheel for you if you're a speed demon.

[techyiam]

19 minutes ago, BKW said:

Alexutlang seems to be a rider that desires speed over most. I don't think the sherman-s is a wheel for you if you're a speed demon.

I also thought it was odd that he bought a Sherman-S since at the outset, the manufacturer clearly states the top speed is 75 km/h.

He must know that, so probably he was curious and just had to get one to try it out.

[MrMonoWheel]

Yeah I found it a bit absurd that he purchased a 45ish mph 20 inch wheel and then his main complaint was that it's not faster and isn't as stable as the 24 inch wheel he's used to. It's like me riding it coming from an 18 inch 35mph v11 and saying it's the best wheel in the world.