Varg rider considering YZ conversion for less weight

[40hp]

Been lurking a bit and think I want to go down the DIY route to replace my Varg due to it's weight. I think I want to stick with electric after seeing how much more seat time I can get riding a woods loop from my house next to a sub division so instead of going back to gas to lighten it up I might DIY a YZ chassis or similar.

Rolling chassis/donor bike -
If you've gone through this, where did you search for one and how long/hard did you have to look until you found one? What should I expect to pay for a clean chassis (no engine or blown engine)?

E parts -
I've seen the predone conversion kits but if I can save a little money and possibly have a better setup for me then I'd go that route. I have a M.E. background and would be able to design my own mounts/brackets and get them made. I think I just need some help on component selection. It seems everyone uses the same QS138 motor, but there are several controllers and new ones/versions popping up all the time. I'd figure out the battery as a last step but would buy a pre made one. Not interested in battery building. I ride my Varg in 40hp so I figure any of the popular controller/battery setups would be work for me. Would this be a good setup? -

EBMX X9000 controller ($1200)
EBMX harness ($139)
QS138 70h v3 - buy from a US vendor or how much can I save buying overseas like alibaba?
Battery ($2500 to be determined)

So besides the donor bike and some customer mounts, am I looking at roughly $4500?

I love riding the Varg on the OHV trails but I'm starting to think it is too much to handle in tighter woods. Since I started riding a few years ago I pretty much only rode fast and flowy OHV trails where I average 25+mph, sometimes 28mph over a 20 minute loop. At those speeds I think the extra weight helps. It handled fine when I occasionally rode MX too.

Now I'm looking at doing some hare scrambles so I started practicing on those type of trails. Besides needing to practice more, I did drop the bike a few times coming out of muddy rutted turns and eventually threw out my lower back pretty bad when picking the bike up on an awkward muddy uphill section. I have pretty good arm strength but the awkward angle and terrain made me use poor technique picking it up. I pretty much never have to pick it up riding OHV trails. I imagine I'll be picking up the bike a few times in a 90+ minute hare scramble.

Just putting this thread out there to motivate me to find a rolling chassis and get started on this project. If I learn enough from it I will probably build an 85 conversoin for me son whose on a E5 now.

 

[Theo]

You may also wait some months and see whether Donut Lab really has solid state batteries. In that case, maybe some months from now it will be possible to use them instead of the more traditional ones with liquid electrolyte.

 

[VINSANITY]

I do really similar riding, ironically also an M.E. - I had an Alta and it was just too heavy - when the Stark came out it is the same weight so that drove me to a build.

I got a lot of help from Don during the process and if you like to build things it’s actually pretty interesting.

You are right about the formula for the build and the cost $4,500 (depending on battery and controller.

Red the QS138 H70 V3 motor. For motor mounts you really can’t beat Lithium King, $150 and he already has designs for the newer bikes YZF, KTM etc.

I just got the EBMX X9000 V3 controller (after many issues with FarDriver) and recommend 100% to pay the extra $$ and go for it, it is easy to set up and after a couple hundred miles zero issues. Another benefit of the EBMX is it can run any voltage up to 96.

The Amorge batteries are well built, nice battery case and really the only option unless you build your own.

I have a 96 volt x 45 amp/hr battery (molicel P45 cells). For me the power is perfect but max range with aggressive trail riding is around 20 miles. I think you may be able to get a little bigger battery in a YZF frame. I really need about 5 more miles range for my typical riding.

The bike is 235 pounds and I think it is a huge difference in how tired I get, I can ride my conversion all day versus the Alta.

I’d say go for it - one other benefit is you can tune your bike exactly how you like real easy with the EBMX app.

Good luck and if you need help reach out.

 

[40hp]

I do really similar riding, ironically also an M.E. - I had an Alta and it was just too heavy - when the Stark came out it is the same weight so that drove me to a build.

I got a lot of help from Don during the process and if you like to build things it’s actually pretty interesting.

You are right about the formula for the build and the cost $4,500 (depending on battery and controller.

Red the QS138 H70 V3 motor. For motor mounts you really can’t beat Lithium King, $150 and he already has designs for the newer bikes YZF, KTM etc.

I just got the EBMX X9000 V3 controller (after many issues with FarDriver) and recommend 100% to pay the extra $$ and go for it, it is easy to set up and after a couple hundred miles zero issues. Another benefit of the EBMX is it can run any voltage up to 96.

The Amorge batteries are well built, nice battery case and really the only option unless you build your own.

I have a 96 volt x 45 amp/hr battery (molicel P45 cells). For me the power is perfect but max range with aggressive trail riding is around 20 miles. I think you may be able to get a little bigger battery in a YZF frame. I really need about 5 more miles range for my typical riding.

The bike is 235 pounds and I think it is a huge difference in how tired I get, I can ride my conversion all day versus the Alta.

I’d say go for it - one other benefit is you can tune your bike exactly how you like real easy with the EBMX app.

Good luck and if you need help reach out.

Appreciate that. Definitely love to build/modify things. The only trouble I have is finding spare time to do it. Sounds like I'm sorta on the right track. Didn't know mounts from Lithium King were that cheap. I might as well go that route to save some time and prototyping.

On the hunt for a chassis.

 

[Erwin P]

You might wanna ask yourself that if you can't lift a 118kg, will you be able to lift a 110 one with a higher COG?

And do not forget, the only big weight saving when using a YZ frame is using a smaller battery.
The Varg as a platform is not that heavy. It's a really lightweight frame. Has the same suspension and wheels to a YZ, the plastics and such are a non factor. That leaves the motor and battery. Both are roughly 35kg. Motor, controller and inverter won't save you that much. Pretty much all you save will be on the battery and you will need to save some extra because the Stark actually has a lighter chassis compared to the YZ.
90 minutes hare scrambless with a way smaller battery will be a serious ask.

I think the same time doing the conversion being spend in the gym or doing bike lift exercises will have a way larger effect

But if it's just for the fun of building it, then sure go ahead and keep us posted. We love projects!

Edit:
Take it from someone who is lifting his Varg and 2 strokes a lott. When lifting on the trails, the gap in lifting a light 2 stroke or the Varg is minimal.
I did some calculations, but apart from building an entirely new bike to save lets say 8kg, if your COG only ends up 2-4cm higher it will take the same force to lift the thing.
It's the difference between needing to lift lift 52 or 56kg if COG stays in place.
Did you consider lowering the Starks suspension to get it on par with it's ICE counterparts (as it has more ground clearance due to not having a frame there). That would not only gain you a ''lighter'' bike to lift, but also result in less of those stupid simple tipovers, resulting in less times picking it up.

Here is an example:

Electro & Co Yamaha YZ-EMX Electric Conversion Kit

The Electro & Co YZ-EMX is the ultimate bolt-on motocross conversion kit designed to turn your Yamaha into a legitimate electric dirt bike. Compatible with the 2014+ YZF, WR chassis, this kit transforms your bike into a powerful electric machine, boasting a quick-change 5.7 kWh battery...

parts.electriccyclerider.com

Comes in at 109kg but with a 5.7kWh battery. Wich is quite a lott smaller than the Varg (90 minutes hare scrambles...?). And you can bet that COG is more than 2-4cm up compared to the Stark.
Here we are also talking a very well setup and thought out package with a serious team behind it. Not a mix and match with steel construction beams etc etc.

Build into the cost estimate that the YZ is a MX platform with hard suspension setup to match. For hare scramble stuff you will want a revalve and to respring. Otherwise it will just result in you falling moer often and spending more power in lifting the bike in total.

 

[40hp]

You might wanna ask yourself that if you can't lift a 118kg, will you be able to lift a 110 one with a higher COG?

And do not forget, the only big weight saving when using a YZ frame is using a smaller battery.
The Varg as a platform is not that heavy. It's a really lightweight frame. Has the same suspension and wheels to a YZ, the plastics and such are a non factor. That leaves the motor and battery. Both are roughly 35kg. Motor, controller and inverter won't save you that much. Pretty much all you save will be on the battery and you will need to save some extra because the Stark actually has a lighter chassis compared to the YZ.
90 minutes hare scrambless with a way smaller battery will be a serious ask.

I think the same time doing the conversion being spend in the gym or doing bike lift exercises will have a way larger effect

But if it's just for the fun of building it, then sure go ahead and keep us posted. We love projects!

Edit:
Take it from someone who is lifting his Varg and 2 strokes a lott. When lifting on the trails, the gap in lifting a light 2 stroke or the Varg is minimal.
I did some calculations, but apart from building an entirely new bike to save lets say 8kg, if your COG only ends up 2-4cm higher it will take the same force to lift the thing.
It's the difference between needing to lift lift 52 or 56kg if COG stays in place.
Did you consider lowering the Starks suspension to get it on par with it's ICE counterparts (as it has more ground clearance due to not having a frame there). That would not only gain you a ''lighter'' bike to lift, but also result in less of those stupid simple tipovers, resulting in less times picking it up.

Here is an example:

Electro & Co Yamaha YZ-EMX Electric Conversion Kit

The Electro & Co YZ-EMX is the ultimate bolt-on motocross conversion kit designed to turn your Yamaha into a legitimate electric dirt bike. Compatible with the 2014+ YZF, WR chassis, this kit transforms your bike into a powerful electric machine, boasting a quick-change 5.7 kWh battery...

parts.electriccyclerider.com

View attachment 15800
Comes in at 109kg but with a 5.7kWh battery. Wich is quite a lott smaller than the Varg (90 minutes hare scrambles...?). And you can bet that COG is more than 2-4cm up compared to the Stark.
Here we are also talking a very well setup and thought out package with a serious team behind it. Not a mix and match with steel construction beams etc etc.

Build into the cost estimate that the YZ is a MX platform with hard suspension setup to match. For hare scramble stuff you will want a revalve and to respring. Otherwise it will just result in you falling moer often and spending more power in lifting the bike in total.

I agree COG has an effect. I don't have experience with YZ electric conversions but if the COG is higher then 30 pounds less static weight isn't much help. Something to think about for sure.

I mentioned in the OP I have pretty good arm strength. I was just trying to get across that my strength is not an issue picking the bike up. I still weight train regularly just with lighter weight/more reps now since I started getting arm pump a while back when doing the heavy weights.

A few weeks ago for fun I decided to see if I could still rep the old weight and I easily benched 225 pounds 10 reps no spotter and I weigh 165 pounds. None of my dirt bike friends can come close to that and most of them weight more than me. If anything, I'm one of the better suited riders for picking up the Varg. I've had a few gas bikes, 4 and 2 strokes previously and I do remember those being quite it bit easier to get off the ground initially. Which is the exact point where I killed my bike, getting it up the first few inches. I hadn't thought about lowering the suspension, I might look into that.

Shane Pinney also complains some of the weight and that guy looks like he has no problem lifting the bike either.

Yes the DIY battery is smaller than the Vargs but I was planning to build it so I can swap it mid race.

 

[Erwin P]

I can see what you mean.
But this is more of a technique issue then the bike being to heavy if i see those weights and reps. I remember the first few times i had the same experience, but after having spend a week in a Hard Enduro terrain that pretty much vanished. Dropping the bike dozens of times does improve technique and stanima

What is kind of different about E bikes and gas bikes is that all the weight on a E is very centralised. That is not going to change on the YZ conversion. ICE bikes have a gastank on top, muffler at the rear, radiators up front etc etc. With E it's pretty much the battery and motor in the centre.

I'm just afraid you're going to chase something while achieving no benefits for the lifting. Sure that 8-10kg gap if you do it as well as those guys might do something for the ride, but i did not hear you complaining about the ride.

I think preventing crashes is the way to go here. You're a light guy so i suppose you're not really tall either? Then a 3-4cm lower bike could really help you not crash as often. That would still leave you with more ground clearance than a YZ from <2023.

 

[Chaconne]

I tend to agree with @Erwin P here especially if you hurt your back more from the awkward angle in terrain rather than the weight alone. That said though, I wouldn't try to dissuade you if you enjoy a DIY project and it is something you really want and will like to do, that is somewhat different.

For me at least, that would be a lot of time and effort away from riding and training which tend to help me more than wrenching. I have taken off the month of January from riding to service my Stark and other bikes while the season is not the best here in New England and even that I don't like to do, but I still keep up my workout program. I am short, light, and old a lighter bike might help a little but not that much for me at least.

I currently have an older WR450 which is heavier than the Stark and I also have a newer KTM 300 2T which is lighter than the Stark all of which I ride in enduro and HE and TBH picking them up after get offs doesn't vary all that much. Often times it is where and how you crash rather than the weight that impacts how much you have to do to get out in my experience at least.

 

[F451]

I'm with you on the weight issue, my ideal tight single track/flowing trails dirt bike is around 200 lbs, up to about 240 max. I've owned everything from 125 2st motocross bikes, 250 2st, 350 4st, and even rode my old KTM 520 EXC in the gnar. Loved them all, but my favorites were the 125 2st's due to the light weight, flickability, and snap from the powerband. At 6'6" and 210 lbs, everyone made fun of me, but I loved it. Never had a problem with power, even in our mountain rides, rode every switchback, climb, obstacles, etc as my much younger and talented riding buddies.

Rode an Alta, had to have one. Had a great time with it for years, but the weight always bothered me. The bike did handle amazing, but you still had to slow/stop 265lbs, and cornering as well I could feel it. If I got loose on the trail or went off trail, especially at speed, I found it was a handful to get back under control. This will sound silly, but at 60+ years old, the Alta was a porker to move around my garage and load/unload my truck, minor, but I did notice it.

My 125's were so much easier to control. I will say the Alta's throttle control is extremely predictable, no clutch, never stalls, etc, were huge benefits in the gnar, the weight was my only issue with the Alta for me. And the precise throttle helped loading into my truck, crawled up my ramp nicely, just had to make sure I was balancing it carefully.

When the Varge was announced at 240 lbs I put down the $100 non-refundable deposit, then they bait and switched us and bike was released at 265 lbs. Major bummer. I demanded my deposit back, they told me to pound sand (more or less). So f-you Stark.

I bought a Sur Ron Ultra Bee, modded it with 21/18 wheels, gummy tires and loved it, around 200 lbs, so much fun. But it was just too small for me, so sold it.

If I was healthier I would definitely be building my own e-dirt bike in the Don (and others) approach. Its been proven and is well documented. So now I'm holding out for that 220-240 lb high quality, full sized, single track slayer with 40+ miles range, quick swap battery, fast charging dirt bike, but at 65 now and more health issues, I'm considering officially retiring and focusing on old sports cars, with age comes the cage (cars) as they say.

Anyway, good luck, and keep us posted if take on the project.

 

[Erwin P]

How about that HVR MX2?
218lbs, just under full size, 41hp, 4,1kWh quick swap battery.
Around now being delivered.

I also wonder if there will be companies overhauling the Varg battery that could also remove 1/4 of cells. That would leave you at 5.4kWh wich is pretty much what the others offer and that should be around 111kg.

 

[F451]

How about that HVR MX2?
218lbs, just under full size, 41hp, 4,1kWh quick swap battery.
Around now being delivered.

I also wonder if there will be companies overhauling the Varg battery that could also remove 1/4 of cells. That would leave you at 5.4kWh wich is pretty much what the others offer and that should be around 111kg.

Thanks, the HVR MX2 looks very interesting, around 218 lbs, $10,351 USD, I will check it out. Unfortunately it looks our current administration has imposed a 15-25% tariff on Germany to import to the USA, so that's a deal breaker right there. I might have to force myself to build one from a KTM, my favorite brand and the one I am most familiar with.

 

[Chaconne]

For anyone who rode XRs and WRs the Stark weight is not really much of an issue. And most modern MX 4Ts don't have and never have had the flick-ability of old school 125 2Ts. My go to machine from 2004-2016 was the yz250f great bike but far from a lightweight flickable pinger.

You needed flickability with those 125 2Ts since that was all you had for a lifeline with the picometer of powerband...

 

[F451]

For anyone who rode XRs and WRs the Stark weight is not really much of an issue. And most modern MX 4Ts don't have and never have had the flick-ability of old school 125 2Ts. My go to machine from 2004-2016 was the yz250f great bike but far from a lightweight flickable pinger.

You needed flickability with those 125 2Ts since that was all you had for a lifeline with the picometer of powerband...

My '07 KTM 125 SX had surprisingly good power down low. I could putt around just above idle and then snap the throttle for acceleration or to hop a log, so much fun. Same for my Husky WR125 that I put a 165 kit on, both bikes single track slayers ha ha.

Op, sorry for the thread jack!

 

[VINSANITY]

One other reason I built a bike is I can swap batteries - mine isn’t quick swap and takes 5-7 minutes. I really didn’t like waiting to charge when I had the Alta.

The Stark had great range but I wish you could just remove a few bolts and swap a battery on it.