STARK VARG (Something new is coming!)

[DonCox]

My friend at XEMX1.com has raced his XE4 model converted YZ250F to electric in an enduro race in Florida ( Mondon Hill ). It was 3 x 10 mile laps. He built a battery swap system into the bike, and he swapped the battery each lap . It took 18-21 seconds to do it. The battery is close to the Alta in cells, 400 VTC6 cells in each pack. After 10 miles, each the packs had about 75V left, which is right at 60%, but would it do another full power lap?
Here is a picture of him on the bike, but he didn't go pro the race, but here is one of the leading riders go pro.

He has made a seat tank thing that flips up and makes the change real quick.
But there is the cost of all of this. He had 4 batteries, one for practice and 3 for the race. You could probably had one charged from practice to use for the 3rd lap, but still an expense.

 

[B. FRANK]

that's like surron's system except bigger. but that may raise the center of gravity a bit more than Alta's battery placement

 

[C5tor]

My friend at XEMX1.com has raced his XE4 model converted YZ250F to electric in an enduro race in Florida ( Mondon Hill ). It was 3 x 10 mile laps. He built a battery swap system into the bike, and he swapped the battery each lap . It took 18-21 seconds to do it. The battery is close to the Alta in cells, 400 VTC6 cells in each pack. After 10 miles, each the packs had about 75V left, which is right at 60%, but would it do another full power lap?
Here is a picture of him on the bike, but he didn't go pro the race, but here is one of the leading riders go pro.

He has made a seat tank thing that flips up and makes the change real quick.
But there is the cost of all of this. He had 4 batteries, one for practice and 3 for the race. You could probably had one charged from practice to use for the 3rd lap, but still an expense.

View attachment 8204

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So how did he do in the race? What class did he ride in?

 

[VINSANITY]

I really am hoping Stark makes battery removal as simplistic as possible so that a swap can be done with reasonable effort in 5 ish mintutes.

If the battery is swappable and the spare can be charged away from the bike it opens up multiple possibilities like MX races where you have full charge for the second moto or in my case if I want to spend the day trail riding a second battery at mid day would double riding hours etc.

I did look at the Varg frame details and some changes would be needed so that bike frame doesn’t come apart when the battery is removed.

It does look like some fairly minor modifications t the Varg frame would keep it connected during battery swap.

The Alta limits my trail rides to 20 miles followed by 60-90 minutes of charging, it is annoying and I really wish I could easily swap a fresh battery with the Alta.

 

[XEMX1]

Golden Masters A Class 1-23-2022 Finished 2 laps at 12 miles each before a tree decided to move while passing it. Each race we get thru we learn something new so we are still changing and modifying our quick swap system. We can do it in 15 sec. but working on a different latching system to make it even faster. Each (5 stack 600 AMP) pack is 400 Sony VTC6 cells and weighs in at just under 50 lbs. We also have a 320 cell (4 Stack 480 AMP) pack for shorter races or Moto's. Batteries are made in Modules of 40 cells. 38lbs.
I am sorry if I don't answer all the questions out there but we are working steadily towards a finished product. sales@xemx1.com

 

[VINSANITY]

That’s pretty impressive. How much does the bike weigh with the bigger pack.

 

[mr.skywalker]

I had a hare scramble race this weekend and I was running a surron. I have a 65Ah 60v main pack and also have a 17Ah range extender I ran for the race(so just about 5kwh of battery) and my bike is basically a small mx bike setup so its about 150-160lbs(original is 120lbs) and Im about 130lbs. The course was about 6 miles based on my GPS I ran and was about 30-40% mx track with some decently tight single track but most was pretty fast flowing. I have my bike setup to switch between 11/8.5/6kw on fly and I needed the 11kw in the short steep climbs so I ended up running it the the whole race other than the mx section I turned it down to 8.5kw since I could carry more momentum. Anyway I made 3 laps and seemed to used about 25% per lap and on the last lap I was right around 30% and decided to try and finish a 4th(had a spare stock battery I could have swapped but it takes a few minutes bc of the range extender mounting and stock battery is limited to 6kw anyway) so I turned the power down and kept a slower pace. In the end the bike died right at 20mile mark at right around 1.5hrs. I think if my battery was a little easier to swap Id do 2 laps then swap and have two bigger batteries like the one i have but I was honestly expecting alot more range but I guess I just ride more aggressive than most others on the surron as I used to get about 17 miles in a race on a stock battery at stock power where this was over 2.5x the battery capacity of that.

I say this to say the only way electrics work for longer range is swapping packs around 30-40% but adds alot of cost to an already expensive bike. At least for me I built my own packs so I only have about $1300 in materials for my 5kwh setup but buying similar setups with be over $3k. That yz setup looks great and is what mfg's should look more into, easy to swap and off bike charging.

 

[fsfs]

Moving on...

... I heard from the interviews of Sebastian that additional "pre-production" bikes were coming online in the January timeframe. We're getting close to the end of the month and it would be good to know if Stark is on schedule or not...

@fsfs anything you can shed on that?

It is not quite so simple. Let me try and explain.

The first two bikes are hand built prototypes -- including hand built electronics, wiring, etc. Things that are designed initially to be hand built are not conducive for mass production. So we have bikes which are in a sense evolving -- they get more and more production ready components. This way we can make sure the components designed to go into mass production are OK as soon as we can. Not all components are mechanically compatible, but most are. We are putting in effort to parallelize as much as possible.

The foundation is solid. Riders of different skill levels have ridden the prototypes. They are all faster on the Varg than on their own bikes and within a couple of laps also. One guy at a track broke the track record by 3 seconds after only two laps; he was not the previous record holder (lap time on that track a little under 2 minutes).

Battery cooling is good. On a loamy track switching between Varg and MXR skilled rider got the MXR into thermal limit (battery) in about 3 minutes. The Varg did not overheat.

Feedback from riders is very positive. The job now is shifting to mass production.

 

[VINSANITY]

I really looked the frame design of the Varg by taking screen shots of a video you guys have on the Varg.

It seems there a 3 large mounting points for the battery.

I would be awesome if the design was basically the same but you could remove the plastics with a few fasteners and then pull 3 large bolts and replace with a fresh battery pack.

In my uneducated opinion the existing design is very close to allowing a battery swap with a rather low level of effort.

In looking at the frame it seems one battery mounting point that also attaches to the motor is the location where removing the bolt makes the frame unstable. Maybe some kind of secondary fastener could solve this issue.

Hopefully you guys consider the input.

 

[Number Six]

So we have bikes which are in a sense evolving -- they get more and more production ready components.

The other shoe as it were ... ?
Let's just hope that the production models don't 'evolve' as a 20 lb heavier machine vis-a-vis those production ready components.
That 242 claimed weight is likely an important component driving the apparent avalanche of pre-orders & overall positive industry buzz.

 

[XEMX1]

That’s pretty impressive. How much does the bike weigh with the bigger pack.

The bike weighs 202 lbs. without any battery. The two different batteries are 48 lbs 10 modules(400 cell pack) 38 lbs 8 modules(320 cell pack)
We will make kit's available in Quick swap or standard battery's. Quick swap system adds about 2 lbs to the bike also.
Hope to do some video at the next race this weekend, or at least the practice lap as I do not normally race with one.

 

[Alta_mxr]

It is not quite so simple. Let me try and explain.

The first two bikes are hand built prototypes -- including hand built electronics, wiring, etc. Things that are designed initially to be hand built are not conducive for mass production. So we have bikes which are in a sense evolving -- they get more and more production ready components. This way we can make sure the components designed to go into mass production are OK as soon as we can. Not all components are mechanically compatible, but most are. We are putting in effort to parallelize as much as possible.

The foundation is solid. Riders of different skill levels have ridden the prototypes. They are all faster on the Varg than on their own bikes and within a couple of laps also. One guy at a track broke the track record by 3 seconds after only two laps; he was not the previous record holder (lap time on that track a little under 2 minutes).

Battery cooling is good. On a loamy track switching between Varg and MXR skilled rider got the MXR into thermal limit (battery) in about 3 minutes. The Varg did not overheat.

Feedback from riders is very positive. The job now is shifting to mass production.

So based on all the added efficiency and I assume better batteries and weight savings. Will the stark make a 3 hour ride at B-Level off-road speeds with a 180# (82kg) rider?

only could ever make 1.25 to 1.75 hours on my Alta MXR. Off-road. And don’t give me to many variables, You guys are claiming 6 hours I know that’s not possible. But 3 hours and I can sell my 350 Ktm!

 

[Matt]

So based on all the added efficiency and I assume better batteries and weight savings. Will the stark make a 3 hour ride at B-Level off-road speeds with a 180# (82kg) rider?

only could ever make 1.25 to 1.75 hours on my Alta MXR. Off-road. And don’t give me to many variables, You guys are claiming 6 hours I know that’s not possible. But 3 hours and I can sell my 350 Ktm!

I highly doubt 3 hours will be achievable. At 100% system efficiency 6kWh used over one hour is like 8hp continuous. Over 3 it's 2.67hp continuous

 

[Alta_mxr]

I highly doubt 3 hours will be achievable. At 100% system efficiency 6kWh used over one hour is like 8hp continuous. Over 3 it's 2.67hp continuous

I’m hoping whoever gets one first will do a real world off-road test and see what kinda of runtime they get.

 

[fsfs]

The other shoe as it were ... ?
Let's just hope that the production models don't 'evolve' as a 20 lb heavier machine vis-a-vis those production ready components.
That 242 claimed weight is likely an important component driving the apparent avalanche of pre-orders & overall positive industry buzz.

About those 20 pounds.

https://twitter.com/i/web/status/1257797005314842626

I guess in Swedish that would be the fet varg.

In all seriousness what is being done doesn't have any real effect on the mass. The prototypes are not highly tuned machines made with unobtanium and expensium that will then be switched to cheap metals for production. The production machines will go around the track faster than the prototypes -- I am sure of that. The prototype machines were hand made by the engineers who designed them. For example, the prototype battery has to be put together carefully; this is easily solved by addition of another pin and socket. It takes a bit of time to engineer this (much more than to carefully assemble a few batteries). The net effect of the pin/socket on mass is zero -- the weight of the pin and socket is offset by the fact that you no longer need a loop of thick wire. Now repeat this in a similar manner several times for various components and you see how the bike is "evolving".

Engineering everything for production from the outset means you get your prototypes later. You see your screw ups later. People get their bikes later.

You just need to make sure you don't design things in such a way that they cannot be adapted for production.

Let me repeat again, this is NOT some bait and switch scheme.

 

[Number Six]

Happy chubby lobos !
Perhaps the efficiencies needed for production will result in a net lowering of OA weight if only slightly. Hooray if true.

Reasoning for the raised eyebrow when 'production ready components' are mentioned ; The 1997/98 KTM 200.
They introduced that all new, much anticipated model with an Ohlins shock designed for the PDS geometry & Marzocchi 50mm forks, when the production units landed in dealerships they were fitted with a diabolical WP shock & much lower spec forks, neither of which proved to be up to the task even when modified.

 

[wwmotors]

The Alta configured the battery and location for the lowest and most central possible CG. That meant placing it further forward and resulted in a 50/50 weight distribution (most ICE bikes are around 55-57/65-63). The Varg pack is slimmer but much taller with a good portion of the pack high in the frame above the drive train. This moves weight to the rear but also makes the CG higher. A higher CG results in more dynamic weight transfer to the front when braking or hitting bumps/whoops and to the rear when accelerating and makes initiating lean angle harder. There are pro and cons to everything, but simply making the front end lighter alone doesn't automatically make a bike handle better.

I do not agree with one point: A motorbike is getting leaned into the corner by steering initially in the wrong direction. So the leverage from the point, where the front wheel is touching the surface to the CG is longer, when the CG is high. That means it will be more agile to lean, when CG is higher! So no one wants a low CG. The best CG hight is the one, where You have no wheely but also no spinning rear wheel when accelerating! This You can adjust with several chainlenghts also! I like th CG position of the ALTA. Its the best copromise, i ever rode! I checked the balance of the ALTA with a cornerweightscale. it was exactly 61kg front 60kg rear!

 

[wwmotors]

I think it is important to have the spare battery option available to those who want it. What good is a $13K bike if it can only be used for 30 minutes and then it has to be charged for 1.5 hours?

Sometimes 1.5 hours is not available. Other times, people may not want to haul around a large, noisy and smelly 240V generator, which is not very sexy, convenient, or neighbor friendly.

Racers and racing teams who want to win races are are willing to pay a lot of money for a spare battery in order to be competitive. It just has to be cheaper than buying a spare bike just for its battery.

I have been working on adding lithium batteries to my van, first 6 kWh, then 14 kWh, and a 4 kW inverter to charge the Alta at the track without making noise. That cost me about than $6K. Bringing an entire extra bike is simpler but costs twice the money, and then I need to wash two dirty bikes af the end of the day. A spare battery that is easy to replace is a much more cheap and elegant solution.

If a spare filly battery can be installed by 1 person with an impact gun in 3-4 minutes, I am sure many people will want it.

Just need a special jack stand to hold and lower/raise the battery while somethins else is holding the bike. That whole contraption will definitely be easier to bring to the track than a 4000-6000 kW generator.

A changeable spare batterypack is in my opinion the only solution for future EMX bikes, not having 50 riders running their generators on the MX track! The trackowners can never care for enough electric power, because they are mainly in the middle of nowhere! If it is possible, to ride nearly 2 hours on one afternoon with 2 batterypacks, most riders will not need to charge anything at the track, but do that later at home. On the other hand, You can charge the sparepack, while the other pack gets ridden, if Your condition wants more riding that day!

 

[F451]

A changeable spare batterypack is in my opinion the only solution for future EMX bikes, not having 50 riders running their generators on the MX track! The trackowners can never care for enough electric power, because they are mainly in the middle of nowhere! If it is possible, to ride nearly 2 hours on one afternoon with 2 batterypacks, most riders will not need to charge anything at the track, but do that later at home. On the other hand, You can charge the sparepack, while the other pack gets ridden, if Your condition wants more riding that day!

Regarding the fact that most tracks are currently in the middle of nowhere, keep in mind that with electric dirt bikes, tracks can be put almost anywhere.

The loud and annoying sound of current ICE bikes and the typical negative reactions to it will no longer be an issue. Tracks and trails will be able to be put almost anywhere, including in cities where there is plenty of infrastructure to support large scale charging.

Of course quick swap batteries would be a great feature now, and going forward, regardless of the charging capabilities of your favorite tracks/trails.

The ability to build new riding facilities in places that could not even be imagined with ICE bikes is huge, a complete game changer.

I wish I was a younger healthier person right now, I'd be gathering investors to build an urban riding facility in Seattle or King County where I live.

There are currently ZERO legal riding tracks/trails in King County. 2.25 million people.

Find an old industrial site, warehouse, empty mall, whatever. Track, trails, small shop/parts, training, coffee/sandwich bar, races, etc. I'm convinced it would be viable, there are tons of riders in King County who have to travel 1-3 hours one way to ride. E-dirt bikes will change all that.

Can't wait to see how the Varge pans out this year, quick swap battery or not, another step in the evolution. Very exciting times to be a dirt bike rider.

 

[Smerwin43]

Honestly I would take an hour swap time if it meant better ergos. Bike feel takes number one spot for me everytime, but considering fsfs mentioned a time around 10-20 minutes I haven’t a worry in the world.