Yamaha YE-01

B. FRANK

Well-known member
They likely have an in-house prototype, but this isn't it.
The bike in these pictures, and the one mounted far and high on the wall at EICMA may as well be made of paper mâché.

I'm sorry to be so sceptical, but even if that wrist-watch battery is real, this bike is 95% YZ from 30 years ago.
All the advantages would need to be in the electronics and software, and Jap-OEMs are not famous for that.
i'm sorry i must have napped for a decade! did you say japanese don't do the best electrics? and it seems old yamahas are the bike that gets converted to electric most often. seems like a cool bike to me, i really like e.m. but i am too old to even think about trials anymore. yamaha does have a reputation for rushing products onto the market before they are ready, but they also have a rep for trying different things, some suck but some are AWESOME! time will tell.
 

Moto Vita

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There is a comparison here. Yamaha was not the first 4 stroke in the series, that was KTM. The better riders however took the price and were remembered as "the first".

Yamaha as a whole is huge, but Stark now is way bigger than KTM was at that time. And they just have to focus on 1 bike. KTM had the whole 50-520 series and 600+.
Stark is also selling more dirtbikes than Yamaha, at least in Europe.

I don't know who is willing to pour more money in for the best riders.
Time will tell. You may be right about the European market, but in the USA, which we all know is the center of the MX universe, Stark is a little blip on the charts compared to Yamaha.
While KTM raced some 4Ts before Yamaha, it was Yamaha that produced the bike that stood the market on it's head and changed the sport.
 

DonCox

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If Yamaha wants to enter the Ebike market, they should follow some of what Stark is doing, but also listen to what the riders want. The weight is a killer. The Whoops at the first WSX killed the Starks, but they weren't the caliber rider as the lead riders. Yamaha has a perfectly good frame, get it to the power of the Stark. Smaller battery for specific uses, and a quick change battery. I have personally ridden conversions on most newer frames, and they handle good. Not my humble opinion, but pro riders really like them. I built an electric Pit bike for Kenny Roberts. I just messaged him and asked if he knows anyone in Yamaha working on these projects. I'll let you know what I can find out.
 

Erwin P

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Yamaha having a perfectly good frame will be of little help. Sure if it's just short AX or SX they can get away with a small ligt battery. But when entering MX they will need a battery at least the capacity of the Stark. That will not fit the YZ frame and if it does it will face even more weight issues than the Stark.
That YZ frame was designed for certain configurations and weight distributions. Removing fuel tank, exhaust etc and placing all that in the centre will upset that balance they found.
Making it quick swap will remove it from being a structural part, wich the rest of the frame needs to be strengthed for to compensate.

In the end clean sheet is the only way to make a serious contender to the Stark.
 

Theo

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Italy
That YZ frame was designed for certain configurations and weight distributions. Removing fuel tank, exhaust etc and placing all that in the centre will upset that balance they found.
Making it quick swap will remove it from being a structural part, wich the rest of the frame needs to be strengthed for to compensate.
SInce the above makes sense I am surprised of the following:
I have personally ridden conversions on most newer frames, and they handle good. Not my humble opinion, but pro riders really like them.
Not saying that it's false, it just sounds odd.

The typical engine mounts on a motocross bikes are:
• one coaxial with the swingarm axle,
• one at the cylinder or cylinder head
• one or more at the crankcases
and according to a book I've read, that top point at cylinder or cylinder head especially changes completely both the flexibility and the way in which the frame vibrates. In that book, written by someone who has worked for reputable motorcycle manufacturers we all know, they say that the stiffness of the engine, when considered as part of the frame, is basically infinite and that top mount stiffens the frame a lot. I don't think that you can't use an ICE frame for an EV, I just think that you have to know what you're doing. Can you install an Amorge battery simulating the engine flexibility? I doubt it's so stiff.
Maybe @Marko_Flux can share his opinion about this: I've noticed that the Primo has a frame that looks like from ICEs and the battery does have some top mounts. Back then, his supermoto team also tried using a supermoto without an engine just for fun, maybe they've noticed that the frame was more flexible :ROFLMAO::
 

VINSANITY

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Texas
All I know is my home built Don Cox recipe is stupid fast, handles great, at least 20 pounds lighter than the Varg, can swap the battery in 5-10 min (ie between motos or trail rides), 20-25 mile range agressive trail riding and can be built for same price as high powered Sur Ron type bikes. The bike carry’s the weight low so handles maybe the best I have ridden, perhaps a lucky co-incidence, but proves Don’s point.

The Varg is awesome, but I it’s the weight I don’t like. I had an Alta EXR which weighs about the same as the Varg and the thing wore me out.

Different tools for different jobs I guess.
 

Erwin P

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Netherlands
Just take any ICE and remove the bolts of the top mount. Even a novice can feel that.
Even hitting the frame with something makes a different sound.
 

DonCox

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Lake Havasu City, AZ
People are racing YZ250F bikes and 450F with electric power trains. Practical experience says it works. Do you even ride a bike Erwin P? Here is a friend who races them in Florida with an A rider who wins on a YZ450F EBike. The wheels aren't falling off the bikes. They do 1 or 2 laps and swap the battery.
Here is a recent race where they didn't have it turned on for the start, and still won.
Here is another race with a more normal start.
This a company with a lot of race experience in Florida on Yamaha framed ebikes and racing it. xemx1.com
There is no perfect built bike. Stark will get more experience as they race more. All the major manufacturers have decades of making bike that work, and survive the rigor's of racing.
 

Erwin P

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Netherlands
I do ride quite a lott of bikes and mostly 2 times a week.
Spend 4 hours riding today actually.

Sure it does work. But non of those conversion bikes have been raced at the highest level MXGP, SX etc etc.
That's where any shortcomings show big time.
 

Beagle

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France
I have a lot of respect for what Don Cox and other electric wizards have been doing for years, great conversions and lots of happy and fast riders, no question about that.

But I get Erwin's point as well. Purely from a physics point of view, swapping a gas engine and fuel tank for an electric motor and its battery (plus hardware like BMS and so on), the weight distribution will change, the stiffness of the engine block/motor and battery block will change. It works with the standard frame but if it's the perfect frame for the gas bike, there's no reason it would also be the perfect frame for the electric bike with different characteristics. If you're thinking about designing an electric bike from the ground up to compete at the highest level you'd probably end up with a different frame because... physics.

It will be interesting to see if Honda and Yamaha first gen electric bikes do come with a frame borrowed from their gas cousins (like the current prototypes). And if so, will they stick with that for the 2nd gen...
 

Theo

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Italy
Exactly: one thing is saying that it works, another is to state that, by doing a conversion, an average Joe like me can rely on a "bulletproof frame", like it should be better than a Varg with its newer design. That ICE frame has proven to be bulletproof for a different use.
Maybe some pros have liked some conversions, but they have probably liked those converted frames in a different way than if used for their intended purposes. And pros have liked the Varg, too.
I haven't seen pictures of this YE-01 without plastics nor of the Honda CR Electric, but they could have started from an ICE frame and then done some modifications that we don't see or notice.
Here are a couple of examples of what experienced people can do:
Some years ago I was a spectator of a race of the Supermoto World Championship and I noticed that a bike had an additional triple clamp, presumably to stiffen the fork.
On a magazine, I've read of a MXGP team who used steel cables run between the triple clamps to stiffen them.
I mean, probably such people would achieve something better than average Joe, converting a bike.
Can average Joe notice these differences? Well, some years ago a guy that became a friend of mine doing some supermoto trackdays with me invited me to use his 2000 CR 250 in a motocross track. My only experience in similar scenarios was using a supermoto in dirt sections of tracks and I had little of that experience. I was overtaken by everybody and I didn't even realize that the front tyre had gone flat. You may expect that, for such a noob, any frame would have felt right. Well, I found that 2000 CR 250 frame to be too stiff and when I went home I did some internet research and I found out that that frame was indeed notorious for being too stiff.

And just one last comment: from what I've seen, those conversions are so different from each other that the fact that some work well doesn't mean that if I do one myself it will be as successfull.
 
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