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

[enaon]

11 hours ago, RagingGrandpa said:

Why not?

 

for the same reasons you are explaining that more fets are better I think. For even heat dissipation surface area is important because at those temperatures radiation transfer occurs, the sandwitch approach makes total radiation area smaller, one board radiates to the other. 

but that is if they do continue using small aluminum plate sinks on EUC's. If indeed they go the s18 way (or rockweel or s2, but the s18 is a first at having no heatsink part at all, only the frame) and use the frame that is designed to act as a heat sink, then I agree that sandwich may not be a problem for fanless, but still harder to do I think. 


PS. The sink integration design on the s18 frame, is one of the reasons I do not believe the s18 is an inhouse desigh. Have a  look at it if you have one, you will notice they change angle by 90 degrees right after the fets, so as to radiate to the opposite side of the sink/frame.

Edited September 17, 2022 by enaon

[UtahRider]

1 hour ago, fbhb said:

Check out this Facebook video posted by Linnea Lin of Leaperkim, testing the durability of what I would presume are the New Sherman-S rims:

Facebook

So, did it pass or fail, I can’t tell.

[techyiam]

I like the fact that the rim bent, and not having pieces cracked off. 

[Jon Wall]

Looks impressive not brittle 

[Planemo]

9 hours ago, Jon Wall said:

If this new Sherman s  had $3500 Ohlins/Rockshock/Fox pro level mtb forks on it,  we would all complain about the $7500 price tag. 

But you dont need to spend 3.5k to get decent forks. A brand new set of Rockshox Domains (with current spec 38mm stanchions) are about £450 and they are very capable for 95% of riders, plus easily serviceable so the tech is out there.

I would happily pay £500 extra to get suspension on an euc over a non- suspended version but until a suspension euc comes out with similar quality suspension on par with industry standard mtb levels we are going to continue to see problems. I've lost count of the number of threads with people discussing issues with fixing the S18/S22/Master etc etc. or even having to go as far as replacing linkages/air cans entirely. In fact the 'old' V11 seems to be the most reliable. Until EUC's move away from using bottom rung suspension components and design I'll stick with unsprung wheels.

[enaon]

11 hours ago, Planemo said:

The wheel aint worth shit if the suspension is crap. Its been done by Fastech which is effectively a cheap no-name chinese brand (compared to Fox, Rockshox and even DNM) and theres been no confirmation that the forks are even servicable which would be a dealbreaker IMO (I do my MTB shocks every 50hrs as reccomended).

I agree, yet this will be the first "normal" implementation of this type of suspension on an EUC, from someone who actually makes suspension systems, not an in inhouse experiment. 

I think it will serve as a nice reference point, for good or for bad. 

Edited September 17, 2022 by enaon

[That Guy]

Looked again at the rendering, the new display may be another highlight of Sherman-S:

Wasn’t Veteram Sherman the first EUC with a display?

[That Guy]

Hmm... I'd rather prefer that pedal opening sound effect on the first revealing cartoon. :-) And yeah, more clay hill footage riding by a small human:

 

[RagingGrandpa]

Suspension:
I wonder if they'll be brave enough to use one side as the spring, and the other as the damper, like has been the trend for modern MTB forks?

Or, will they be equal and symmetric, like motorcycle forks?

 

MTB forks rely on a stiff strong crossover structure... I don't see one in Sherm-S, so I bet it's moto-style.

[mrelwood]

2 hours ago, RagingGrandpa said:

wonder if they'll be brave enough to use one side as the spring, and the other as the damper, like has been the trend for modern MTB forks?

I've been wondering about the same thing. But just like you've also noticed, the bridge between the tubes is very shallow. I also don't think that separate tubes would be a good idea on an EUC, so I hope that they are using symmetrical tubes. Even when it makes you adjust the settings on both sides.

[DavidB]

On 9/17/2022 at 12:59 AM, Paul g said:

@chanman I noticed the poor heat dissipation problem can lead to components failure (FETs as well) in many cases so the easier is the cooling the better for me. I also prefer a fanless design over one with a fan. Less FETs with more power will occupy a much smaller area and would automatically lead to fan design in my opinion. For less FETs start using copper heatsinks? Maybe that will be the next step, since 24 FETs seem to have reached a limit. 

The heat dissipation is almost double for copper.

Source: https://www.gabrian.com/copper-vs-aluminum-heatsinks/ 

 

Copper is 3.3 times the density of Al alloy and 4.4 times the price at todays rate (LME). Al has a good set of parametres that is hard to beat. I'm not even sure why LeaperKim is going magnesium on the battery covers. Sure it is lighter but not as strong as Al. I guess it is marketing. I'm sure the covers would be just as strong if they used thinner Al of the same weight. Well if the batteries burn you wont have to worry about the Al covers melting as the Mg will go up like a roman candle.

[fbhb]

12 hours ago, RagingGrandpa said:

Suspension:
I wonder if they'll be brave enough to use one side as the spring, and the other as the damper, like has been the trend for modern MTB forks?

@RagingGrandpa, I guess there is a strong possibility with Leaperkim choosing Fastace to develop the suspension for them (rather than cobbling something together themselves) a version along those lines may well have been adapted/modified for EUC use.

On the Fastace website, their own MTB fork (as currently used on the Sur-ron/Segway e-dirt bikes) is certainly designed that way, so that in itself could signal the possibility of Fastace translating/implementing a specifically designed EUC version for the Sherman-S and IMHO I expect they will have:

 Fastace ALX13RC MTB Bike Front Fork 26 27.5 29 Inch Compatible Double Shoulder Control Downhill Suspension best for Surron Talaria Segway

Edited September 20, 2022 by fbhb

[Paul g]

5 hours ago, DavidB said:

Copper is 3.3 times the density of Al alloy and 4.4 times the price at todays rate (LME). Al has a good set of parametres that is hard to beat. I'm not even sure why LeaperKim is going magnesium on the battery covers. Sure it is lighter but not as strong as Al. I guess it is marketing. I'm sure the covers would be just as strong if they used thinner Al of the same weight. Well if the batteries burn you wont have to worry about the Al covers melting as the Mg will go up like a roman candle.

Well, it is not Mg, It’s Mg alloy actually. It is used in aerospace industry. If it would be Mg it would be a fire hazard since it reacts violently with the O2 in the air. 
Cu is the next step in cooling compared to Al, just like it happens in laptops, for example, though there are differences as well.

[Rollin-on-1]

8 hours ago, DavidB said:

Copper is 3.3 times the density of Al alloy and 4.4 times the price at todays rate (LME). Al has a good set of parametres that is hard to beat. I'm not even sure why LeaperKim is going magnesium on the battery covers. Sure it is lighter but not as strong as Al. I guess it is marketing. I'm sure the covers would be just as strong if they used thinner Al of the same weight. Well if the batteries burn you wont have to worry about the Al covers melting as the Mg will go up like a roman candle.

We will get a nice sparkler show when someone lays it down at speed and it goes sliding down the street on its side!💥💥💥💥

[chanman]

If the battery goes up in flames and the cover starts burning at least the fire department will be able to see it from miles away!

[Paul g]

The suspension seems to work well.

Edit: OK Mr LeaperKim, now we also need the sound of the wheel when performing those nice jumps. 

 

Edited September 23, 2022 by Paul g

[techyiam]

1 hour ago, Paul g said:

The suspension seems to work well.

By the looks of it, I would say one of the best so far, albeit that it may bottom on the big hits, or very heavy riders. But for me, it looks like heaven.

[meepmeepmayer]

The suspension in the V13 stair video keeps the wheel amazingly steady. If the ShermaS suspension is just as good... I need to start saving!

[Paul g]

1 minute ago, techyiam said:

By the looks of it, I would say one of the best so far, albeit that it may bottom on the big hits, or very heavy riders. But for me, it looks like heaven.

They all bottom out, the “How” it bottoms out is now the big question. I hope they’ve learned from the others and put some thick rubber ring. The T4 seemed to got it right.

[alex5454]

Hi guys, when is sherman S expected to come out?

[techyiam]

20 minutes ago, alex5454 said:

Hi guys, when is sherman S expected to come out?

eWheels says they will ship out to customers in late November. 

Edited September 23, 2022 by techyiam

[Jon Wall]

New video showing Sherman s rock crawling. Looks light and nimble 

[Jon Wall]

Linnea lin Veteran on Facebook has the video.  I don't know how to post it here 

[fbhb]

6 hours ago, Jon Wall said:

Linnea lin Veteran on Facebook has the video.  I don't know how to post it here 

https://www.facebook.com/linnea.lin.14/videos/391895296480891/

[enaon]

6 hours ago, Jon Wall said:

New video showing Sherman s rock crawling. Looks light and nimble 

the dude riding it is the "Kingsong guy", not saying the Sherman will not be excellent, but he is not a normal rider.