Thinking about getting another e-dirt bike: Which One?

[Mark911]

You can go to my Instagram and see a bunch of build photos and comments regarding many of my builds. Login • Instagram

 

[73Thing]

I too have been thinking of buying another E-bike other than the Alta as well. I have 2 Altas and would like to keep one and have the second for different type of riding. KTM and Escape are being considered but if you look at the price out the door at around ~12000$ and resell of a like new Alta ~@8000$ish it becomes hard to sell an Alta and pay up an extra 4000$ for a bike with less power/speed, battery range and suspension. Also have to add those bikes will likely need upgrading $$$$
Thats a tough decision.

 

[DonCox]

I have built 4+ electric dirt bikes over the last 10 yrs. I have my KTM on EV Album #3817. It gives some detail on that build, which I still ride . But I just built a Yamaha 2008 YZ along the same specs as the Alta. 50HP, an ME1302 motor, 72V 63AH 630A peak ( 420 Sony VTC6 cells), approx 250lbs. Kelly controller that can handle 700A.
I have met a few other enthusiasts who wanted to build an electric dirt bike also. I have now helped them over the years, and the student has surpassed the teacher...
One friend is now building his on a Honda CR frame, with a ME1304 motor, and an BAC8000 controller, still in the build phase, but my friend in Florida has built, and is going to be selling the essential's needed to convert a 2014 Yamaha YZ bike. He is going to sell a kit or just the parts, with the motor and all the machined parts, a custom Curtis controller, and a battery pack that will fit that model bike. Here are a couple pictures of his bike just a months ago. Where he lives, a friend has an Alta and he is using that as his benchmark to be able run races and enduros in Florida.
He has access to all the machine tools to build this all right. Mark911, though he is envious of your spot welder... The battery pack have always been the most challenging. We have yet to prove our packs as fully as the ALTA packs. I got to ride an Alta at the races at Pala 2 weeks ago, and it is impressive. ( just some pit and field riding, not the track) but my friend did race it on Friday before the National in the support races. He did good the second race, he broke a bunch of spokes the first race. Here is a link to the video of him.
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[Philip]

I have built 4+ electric dirt bikes over the last 10 yrs. I have my KTM on EV Album #3817. It gives some detail on that build, which I still ride . But I just built a Yamaha 2008 YZ along the same specs as the Alta. 50HP, an ME1302 motor, 72V 63AH 630A peak ( 420 Sony VTC6 cells), approx 250lbs. Kelly controller that can handle 700A.
I have met a few other enthusiasts who wanted to build an electric dirt bike also. I have now helped them over the years, and the student has surpassed the teacher...
One friend is now building his on a Honda CR frame, with a ME1304 motor, and an BAC8000 controller, still in the build phase, but my friend in Florida has built, and is going to be selling the essential's needed to convert a 2014 Yamaha YZ bike. He is going to sell a kit or just the parts, with the motor and all the machined parts, a custom Curtis controller, and a battery pack that will fit that model bike. Here are a couple pictures of his bike just a months ago. Where he lives, a friend has an Alta and he is using that as his benchmark to be able run races and enduros in Florida.
He has access to all the machine tools to build this all right. Mark911, though he is envious of your spot welder... The battery pack have always been the most challenging. We have yet to prove our packs as fully as the ALTA packs. I got to ride an Alta at the races at Pala 2 weeks ago, and it is impressive. ( just some pit and field riding, not the track) but my friend did race it on Friday before the National in the support races. He did good the second race, he broke a bunch of spokes the first race. Here is a link to the video of him.
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Hey Don! I will be in Havasu in 1 month. Hoping to check out your conversion. And you could benchmark my Altas all winter long at 928MX or at Western Raceway!

Yamaha should be a great platform for a motocross e-bike. Stable and not twitchy, strong enough to handle the extra weigh of the motor, best suspension in the business. I like the swing arm sticker!

That Google Drive is not shared with the rest of the world, so we cannot see the videos. You could copy them to your own Google Drive and then share with all. Or ask your friend to share and let us see it.

 

[DonCox]

Hey Don! I will be in Havasu in 1 month. Hoping to check out your conversion. And you could benchmark my Altas all winter long at 928MX or at Western Raceway!

Yamaha should be a great platform for a motocross e-bike. Stable and not twitchy, strong enough to handle the extra weigh of the motor, best suspension in the business. I like the swing arm sticker!

That Google Drive is not shared with the rest of the world, so we cannot see the videos. You could copy them to your own Google Drive and then share with all. Or ask your friend to share and let us see it.

I opened up the link to anyone. Let me know if it works for you. I look forward to seeing you out here again. I am going to the moto track out here on Nov7 or 8th, it is open that weekend, and Nov 21 and 22.

 

[Philip]

The video now works, thank you!

I should be in Havasu on the morning of the 23rd.

 

[F451]

I have built 4+ electric dirt bikes over the last 10 yrs. I have my KTM on EV Album #3817. It gives some detail on that build, which I still ride . But I just built a Yamaha 2008 YZ along the same specs as the Alta. 50HP, an ME1302 motor, 72V 63AH 630A peak ( 420 Sony VTC6 cells), approx 250lbs. Kelly controller that can handle 700A.
I have met a few other enthusiasts who wanted to build an electric dirt bike also. I have now helped them over the years, and the student has surpassed the teacher...
One friend is now building his on a Honda CR frame, with a ME1304 motor, and an BAC8000 controller, still in the build phase, but my friend in Florida has built, and is going to be selling the essential's needed to convert a 2014 Yamaha YZ bike. He is going to sell a kit or just the parts, with the motor and all the machined parts, a custom Curtis controller, and a battery pack that will fit that model bike. Here are a couple pictures of his bike just a months ago. Where he lives, a friend has an Alta and he is using that as his benchmark to be able run races and enduros in Florida.
He has access to all the machine tools to build this all right. Mark911, though he is envious of your spot welder... The battery pack have always been the most challenging. We have yet to prove our packs as fully as the ALTA packs. I got to ride an Alta at the races at Pala 2 weeks ago, and it is impressive. ( just some pit and field riding, not the track) but my friend did race it on Friday before the National in the support races. He did good the second race, he broke a bunch of spokes the first race. Here is a link to the video of him.
Meet Google Drive – One place for all your files

Thanks for the detailed response Don!

I had not really considered "rolling my own", but with Mark911's post, and your post, it certainly sounds like a viable option, especially if the majors aren't going to be offering anything anytime soon, and if the Sur Ron Storm Bee is still an unknown for availability, performance, price, parts support, etc.

Using "off the shelf" components that are well known and understood, and the idea of possibly continuing to upgrade components over time is another interesting aspect of all this.

And I love the idea of a kit that could be assembled. I wish your Florida buddy was closer (and Mark911 too), I would love to learn more about his efforts. Please keep us posted here on AOF if he has a website, or whatever where we can learn more about his kit. His e-Yamaha looks killer.

And here's a direct link to your EV Album #3817, I didn't even know this website existed, more learning for me! Thanks again! -Ed

 

[bayodome]

I have built 4+ electric dirt bikes over the last 10 yrs. I have my KTM on EV Album #3817. It gives some detail on that build, which I still ride . But I just built a Yamaha 2008 YZ along the same specs as the Alta. 50HP, an ME1302 motor, 72V 63AH 630A peak ( 420 Sony VTC6 cells), approx 250lbs. Kelly controller that can handle 700A.
I have met a few other enthusiasts who wanted to build an electric dirt bike also. I have now helped them over the years, and the student has surpassed the teacher...
One friend is now building his on a Honda CR frame, with a ME1304 motor, and an BAC8000 controller, still in the build phase, but my friend in Florida has built, and is going to be selling the essential's needed to convert a 2014 Yamaha YZ bike. He is going to sell a kit or just the parts, with the motor and all the machined parts, a custom Curtis controller, and a battery pack that will fit that model bike. Here are a couple pictures of his bike just a months ago. Where he lives, a friend has an Alta and he is using that as his benchmark to be able run races and enduros in Florida.
He has access to all the machine tools to build this all right. Mark911, though he is envious of your spot welder... The battery pack have always been the most challenging. We have yet to prove our packs as fully as the ALTA packs. I got to ride an Alta at the races at Pala 2 weeks ago, and it is impressive. ( just some pit and field riding, not the track) but my friend did race it on Friday before the National in the support races. He did good the second race, he broke a bunch of spokes the first race. Here is a link to the video of him.
Meet Google Drive – One place for all your files

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Looks like an awesome conversion. I have a 2014 YZ250F that I would like to convert. Can you connect me/us with the guru behind the conversion and kit?

 

[DonCox]

Looks like an awesome conversion. I have a 2014 YZ250F that I would like to convert. Can you connect me/us with the guru behind the conversion and kit?

I want to just say that this bike isn't ready for production yet. Nothing is 100 percent ready for the market. If they want to buy now, they would be helping helping the development. But, everything is more expensive now than the "KIT"s will be in the future.
Hopefully he will have the web site up by next week and he will field your questions thru emails. He will have some more photos and info up there. There is nothing there yet.
He owns a business, and is trying to run that, source out production runs on the parts for this, moto practice on Thursday, race on Sunday, and still building the prototype.
Here is his statement,
These are still one off's. I have only contracted to make battery packs as of now.
Motor and motor parts, Cases, Covers, Gears, Shafts, Bearings, Rotor and gaskets are
still awaiting quotes. All frame parts needed would be a couple months to have made.
This is all to much to make in house on our CNC. Prototyping is fine, not so much
for production.
Seat and seat pan is in the final design stage, and will use the stock sized seat covers.
Awaiting a custom controllers from Curtis, better suited for this platform.
Working as much as we can to make this a possibility.
The idea is to have a "Quickly replacement" battery, for enduro and longer races. That is the reason for the seat mod to make the Quick Change battery system work. He is having the batteries built in modules, for easy replacement, the motor/output shaft gear assembly will fit right into the Yamaha frame , with very little frame mods.
And for you in particular, Bayodome, when he gets the website up, you can talk to him about being a first builder to help with development.
I will post the website hopefully next week.

 

[Mark911]

The modern MX bike is a true wonder. It's evolved with and sometimes lead with technology that allows a wide range of applications without much, if any, compromise. The applications are almost limitless. From motocross, supercross, offroad, enduro, cross country, desert, hillclimb, (I could go on), within practically any environmental condition a human can endure it's a proven performer. In other words, it's a tough act to follow yet alone try to beat!

The electrictrification of this successful platform, however, is not nearly as evolved. Therefore, the electric bike needs to be somewhat "tailored" technologically in order to compete and/or beat it's ICE counterpart. I don't see this changing anytime soon and will require several "breakthrough" in specific technologies and manufacturing processes. Time will tell as usual.

In regards to my development work, I've focused specifically on Professional level (not National level) motocross and supercross to dictate my bikes specifications. To date, nothing can touch the performance capability of our own Alta Redshifts when it comes to this specific application. That's quite an accomplishment, particularly in the area of battery pack design and durability. When was the last time you saw or heard of an Alta DNFing a race because of an internal mechanical failure? Sure, we break wire bonds here and there but the cells stay in place as does the pack! You'd think that should go without saying, but you'd be surprised how many "hand built" or repurposed ebay "EV packs" simply disintegrate when exposed to the rigors of the track or a hard crash. The mechanical design of the Alta is virtually bulletproof from a stress standpoint and any aftermarket or "kit" pack you might be considering (even mine) needs to be critically reviewed with motocross loads in mind.

Unfortunately, even as good as it is, the Alta falls short compared to it's ICE competition (remember, my criteria is local Pro competition). Although opinions vary, from my personal experience there are three, maybe four reasons for this. 1) Battery pack will thermal limit under the demands of a fast rider, 2) weight, 3) battery charging logistics, 4) battery pack capacity. Of course, weight is typically the penalty of most attempts to rectify the other problems, so it's always a tricky balance.

While keeping the great performance characteristic all us Alta owners are accustomed too, my Yamaha 2 stroke based full sized conversion focus on what I believe to be the two most important issues, battery pack thermal limiting and weight.

My pack design utilizes water cooled "cold plates", a water pump, and an external radiator to extract heat from the negative ends of each cell similar to the way Alta pulled the heat passively (with the help of some heat spreaders) to the outside housing. In addition, my design pulls heat from the positive ends of each cell as well. The much better thermal conductivity and transfer characteristics of my design should put thermal limiting issues to bed. Now, a Pro level rider wont be backing off halfway through a race because the "little yellow" light is flashing.

Mechanically, my battery pack design utilizes the same packaging techniques and materials that make the Alta pack so reliable. I've actually improved on the one failure mode by eliminating the hundreds of wires/wire bonds that Alta uses and replacing them with lower resistance and more reliable pure copper bus bars.

Water cooling, although the answer to several problems, does add weight, To counteract this increase the actual amp hour total for the pack was reduced by 25%. Still enough for one 15-20 minute moto. Net net, the pack isn't going to decrease or increase the bottom line weight. An overall 15-20 lbs savings is budgeted, however, it comes from general component savings not any one specific design revision.

The use of water cooling of the pack opens up other opportunities as well. For example, hot days and/or fast charging between motos, although many times very necessary, virtually guarantees an early visit from Mr. little yellow flashing light. However, one viable option with my pack would be to pump chilled water through the pack while charging between motos. This not only keeps the pack much cooler than otherwise possible but allows for "sub ambient" pack temps before every race! The lower cell temps increases the thermal headroom to limiting and helps prolong the life of the pack as well. All good stuff.

Granted, the goals of my development effort wont appeal to anyone but the purest MX/SX racers, but that's a consequence of present technology which drives the R&D process.

 

[TCMB371]

@DonCox pretty sure you were the guy on that home built electric Yamaha i met at pala, right? That was @Jayfox911 's bike you rode, and he's the guy you filmed racing the amateur event on Friday.

 

[Jayfox911]

@DonCox pretty sure you were the guy on that home built electric Yamaha i met at pala, right? That was @Jayfox911 's bike you rode, and he's the guy you filmed racing the amateur event on Friday.

Yup. That’s me in the video. Haha

turns out the Ktm wheel I was using has smaller diameter spikes than the stock Alta. Reminder to not case big hard packed jumps using the KTM rear wheel.

 

[DonCox]

Yes that was me at Pala. Nice to connect a link to a face. Mark911's article is quite informational also. The battery heat and size, and weight are the 3 major challenges in electrifying a moto bike. My friend in Florida has been working thru these challenges. Unfortunately none of the majors want to really take this on, so we are just going to have to do our own until we get it right. We do have a great role model to follow in the ALTA.

 

[DonCox]

I am somewhat new to this forum, I guess I am supposed to hit Reply ...

 

[C5tor]

I am somewhat new to this forum, I guess I am supposed to hit Reply ...

Only if you wanted to quote something in a previous post. We’ll probably figure it out otherwise.

 

[bayodome]

I want to just say that this bike isn't ready for production yet. Nothing is 100 percent ready for the market. If they want to buy now, they would be helping helping the development. But, everything is more expensive now than the "KIT"s will be in the future.
Hopefully he will have the web site up by next week and he will field your questions thru emails. He will have some more photos and info up there. There is nothing there yet.
He owns a business, and is trying to run that, source out production runs on the parts for this, moto practice on Thursday, race on Sunday, and still building the prototype.
Here is his statement,
These are still one off's. I have only contracted to make battery packs as of now.
Motor and motor parts, Cases, Covers, Gears, Shafts, Bearings, Rotor and gaskets are
still awaiting quotes. All frame parts needed would be a couple months to have made.
This is all to much to make in house on our CNC. Prototyping is fine, not so much
for production.
Seat and seat pan is in the final design stage, and will use the stock sized seat covers.
Awaiting a custom controllers from Curtis, better suited for this platform.
Working as much as we can to make this a possibility.
The idea is to have a "Quickly replacement" battery, for enduro and longer races. That is the reason for the seat mod to make the Quick Change battery system work. He is having the batteries built in modules, for easy replacement, the motor/output shaft gear assembly will fit right into the Yamaha frame , with very little frame mods.
And for you in particular, Bayodome, when he gets the website up, you can talk to him about being a first builder to help with development.
I will post the website hopefully next week.

Keep me/us posted! All very interesting.

I truly believe conversion kits are the way to go forward with e-motos at the moment. Why bother with chassis development when the major OEMs have already provided amazing platforms to work with? Focus on the power source instead and we can get to an electrified moto world much faster.

 

[DonCox]

Keep me/us posted! All very interesting.

I truly believe conversion kits are the way to go forward with e-motos at the moment. Why bother with chassis development when the major OEMs have already provided amazing platforms to work with? Focus on the power source instead and we can get to an electrified moto world much faster.

Will keep you posted.
I went to @Mark911 Instagram page last night. I like the work you, Mark911, have done on your YZ125 Electric conversion's battery box. The motor you are using is small size for the KW output, and no jackshaft, good weight savings. What is the total bike weight and how many KW of battery do you get, with todays technology.
What is your overall gear reduction. Your motor is rated at 4400rpm at I think 96V. We are running at about 6.86 to 1 total gear reduction, and still need more low end power at about the same power KW as you. Have you thought of a clutch? We are pondering this...

 

[Mark911]

Will keep you posted.
I went to @Mark911 Instagram page last night. I like the work you, Mark911, have done on your YZ125 Electric conversion's battery box. The motor you are using is small size for the KW output, and no jackshaft, good weight savings. What is the total bike weight and how many KW of battery do you get, with todays technology.
What is your overall gear reduction. Your motor is rated at 4400rpm at I think 96V. We are running at about 6.86 to 1 total gear reduction, and still need more low end power at about the same power KW as you. Have you thought of a clutch? We are pondering this...

The base rpm is 4400 but will spin over 7000 with field weakening. Yes, very small and light. The motor uses a proprietary "through the coils" water-cooling design which is an order of magnitude more efficient at removing motor heat than simply circulating water around the stator housing (like Alta and most other water cooled PMAC motors). This allows for much greater current (HP) with respect to mass and size.

No gear reduction planned, but I'll know better after testing. No doubt I'll be starting with a 66t rear sprocket. In addition, a have a very simple but robust 50% gear reduction design on CAD if needed.

I'm not a fan of "electronic" clutches and a mechanical clutch is way too big a weight hit. We'll see.

 

[MX2Live]

Ok, so you’re talking about the Segway 260, my understanding is that it is the same frame as the Light Bee X, so not any bigger physically.

I went with Luna Cycles Sur-Ron. Luna has great customer service, I have found out that all you have to do is email them and they will take care of you. I have made a couple mods, Motocross bars, grips, and will soon add hand guards. The first place I took mine was straight to the motocross track. I had a blast.

 

[VINSANITY]

The base rpm is 4400 but will spin over 7000 with field weakening. Yes, very small and light. The motor uses a proprietary "through the coils" water-cooling design which is an order of magnitude more efficient at removing motor heat than simply circulating water around the stator housing (like Alta and most other water cooled PMAC motors). This allows for much greater current (HP) with respect to mass and size.

No gear reduction planned, but I'll know better after testing. No doubt I'll be starting with a 66t rear sprocket. In addition, a have a very simple but robust 50% gear reduction design on CAD if needed.

I'm not a fan of "electronic" clutches and a mechanical clutch is way too big a weight hit. We'll see.

Hey Mark, do you have any pictures to post showing work in progress.