Kawasaki ninja to electric, chain or hub, ideas?

[eldan]

Hi everyone,
I don’t post much but I have been a member for while, since my first E-longboard I made with the help of this amazing forum!!

On to business;
As the title states, I picked up 2009 Kawasaki ninja 500 for very cheap however it needs upwards of $1000 to get it street legal.

So I decided to go electric conversion. I’m familiar with the gist of it as I did the E-longboard but I’m deathly gonna need help because it’s a bigger project.

As a starting point, the motor, I have two options and those are either to go chain drive or change the wheel and make it an in-hub motor. In-hub wise I’m thinking about getting on AliExpress the QSMotor 17” * 6”.

My main question is, which is the better/simpler/cheaper? Comparing the in-hub vs using the chain that’s already there and replacing the engine with an electric a chain drive motor. I could probably tie it to the transmission?! For higher speeds? Maybe Idk I’m just spitballing here.

Does anyone have any experience with the QSMotor,
specifically the larger sizes? What’s the top speed you can get on them? Because I believe these go as Hugh as 12000 W.

Welp, if you made it this far,
Thanks for reading! I hope I was detailed enough.
I’d definitely appreciate any feedback including tips like “wish I’d known that before” ideas, for now or down the line on this project. I take notes. Thanks in Advance!

PS will add pictures soon.

 

[ScooterMan101]

Do you live in a Hilly area of the World or a Flat area of the World ?

 

[Balmorhea]

The bike is already set up for chain. So those parts you get to keep will be reliable, and the suspension will work correctly with the original amount of unsprung weight, if you use a shafted motor.

Hub motor is inherently simpler, but it disrupts the chassis dynamics as developed by the original manufacturer.

So are you an "inherently simpler" kind of guy, or a "works better using the engineering that's already done" kind of guy?

I could go either way, depending on the circumstances. Is probably favor the path that left me with the least work on my end.

 

[mistercrash]

Consider what you want to do with the bike. If it's a commuter that you don't plan to drive like a maniac, a hub motor will do just fine and leave more room for a bigger battery. As it was said, it will change the dynamics of the rear suspension but this will not be a problem if the bike is driven normally. If you're a ricer and like to scrape the foot pegs in the turns, then stay with the chain drive.

 

[Voltron]

If you want simplicity, maybe hub. But if you want performance, def chain

 

[Voltron]

If you want simplicity, maybe hub. But if you want performance, def chain. Electric motors love their RPMs like a sailor loves his rum, so chain lets you run higher RPM on the motor than the wheel. Hub motor locks you into wheel RPM.

 

[eldan]

Thank you all for the respnses! @ScooterMan101 @Balmorhea @mistercrash @Voltron

Do you live in a Hilly area of the World or a Flat area of the World ?

FLORIDA - Flat as possible, The biggest hill is a garbage land fill LOL

So are you an "inherently simpler" kind of guy, or a "works better using the engineering that's already done" kind of guy?
I could go either way, depending on the circumstances. Is probably favor the path that left me with the least work on my end.

I think we are all "simpler" kind of guys. If it were a situation where I had a naked frame, I would choose hub motor. But since it's mostly there, that's when the crossroads come in to play. Is it easier to remove everything and start clean? or work with what's there..
So I see this as a triangle with each side being; (SPEED > WEIGHT > PRICE). Usually with the triangle you can have 2 sides but the 3rd will cost. e.g. FAST & LIGHT will be EXPENSIVE, but if you go CHEAP and LIGHT it will be slow..hope that clarifies if you're not familiar.
The Question would be, Which setup would be better for PRICE & SPEED, HUB or Chain?

Consider what you want to do with the bike. If it's a commuter that you don't plan to drive like a maniac, a hub motor will do just fine and leave more room for a bigger battery. As it was said, it will change the dynamics of the rear suspension but this will not be a problem if the bike is driven normally. If you're a ricer and like to scrape the foot pegs in the turns, then stay with the chain drive.

Based on the name, can I assume you lean more ricer..or used to be?
First motorbike, so def not a ricer lol. It would most likely be a commuter, but honestly its more for the love of the Build...I did an E-longboard, If i had the money this would be an E-Car or E-Plane E-Jetpack (lol thats more in the future when the tech gets invented)
I see most people E-Bike goals are about 100-120 km/h. I would say 120km/h is a good top speed goal to have..

If you want simplicity, maybe hub. But if you want performance, def chain. Electric motors love their RPMs like a sailor loves his rum, so chain lets you run higher RPM on the motor than the wheel. Hub motor locks you into wheel RPM.

Chain, huh.. Q, What type of motor would you think would be needed? and would it chained directly to the wheel (gear ratio of course) or would it somehow connect through the Transmission? Possibly benefit with top speeds ? idk

So what I got so far..
HUB (maybe QSMOTOR 17")
>PROS> Easy
>CONS> RPM limited

CHAIN Drive motor (Any recommendations?)
>PROS> More Technical
>CONS> More control over RPM

List of Q from the post (im trying to have this organized as best as possible)

• Is it easier to remove everything and start clean? or work with what's there..

• Which setup would be better for PRICE & SPEED, HUB or Chain?

• What type of motor would you think would be needed?

• would it somehow connect through the Transmission?

• I know there are a lot of variables, but what are the top speeds I can expect with the QSmotor 17" * 6.0" ? If anyone knows.

 

[Voltron]

Check out Isle of Man TT e-motos if you haven't yet.. generally it's single speed to the wheel, a few teams use transmissions, and aero cleanup for efficiency gains.




Team Mugen started crushing so hard lots of other teams gave up.

Personally, I think this is one of the most beautiful, form following function motorcycles ever created.

 

[Voltron]

But as written earlier, for basic street commuting, hub could be fine. Quiet, low maintenance, no dirty chain spraying your work clothes... Lots of pluses for reliable commuting.

 

[eldan]

But as written earlier, for basic street commuting, hub could be fine. Quiet, low maintenance, no dirty chain spraying your work clothes... Lots of pluses for reliable commuting.

I’m definitely leaning more towards hub, for the simplicity & other benefits. I was worried that I was missing an opportunity or something b/c it was mostly built.

Now I just have to figure out the KV of that QSmotor 17 “ x 6 “ hub motor to calculate speed options.

 

[Dui ni shuo de dui]

I'd go with a hub motor, it has the most benefits compared to inboard.
-Power isn't a concern unless you want to surpass a 1000cc sport bike. Which, really, doesn't make much sense on open roads if you want my opinion. With a 12kw QS motor, a good controller and a powerful battery you can take off faster than a 600cc.
-Suspension work and such isn't a concern unless you plan on circuit racing. The weight will be heavier for sure, it will take a bit of getting used to maybe, but it will accomodate for that, no worries. That's much less critical than people like to say.

-This configuration is easier to set up and requires the smallest amount of modifications.
-You get tons of space for the battery, which matters a lot not only for range but also performance wise. It serves no purpose to install a super powerful inboard motor if you cannot supply it with enough current because your battery is too small, or if in order to supply such amount of current you have to use some unsafe and not durable battery chemistries.
-It's generally cheaper

If you have the bucks, then yeah go for a QS 12kW hub motor, QS is really reliable once you passed the first month of use, plus their motors can take way more power than what's advertized.
Pretty sure the 12KW can take 60 KW without any problem. Friend of mine got the 8KW and reliably drops more than 35-40KW in it. Plus they have insane amounts of torque.

Max speed will mostly be constrained to your battery voltage. To give you a ballpark idea, 72V should give you about 80-90kmh, 84V around 100-110kmh , etc. But if you have a controller that can do flux weakening, then you can improve your top speed even with a low voltage battery (at the expense of high speed efficiency, so you burn more electricity basically). For instance, my bike reaches 120kmh despite using a 72V battery, because the controller has the flux weakening technology. I wouldn't recommend you to calculate a KV yourself, go with whatever they recommend you/whatever they do as standard. They are much more experienced than you are at making motors, you are very likely to make a wrong choice by interefering.

 

[eldan]

If you have the bucks, then yeah go for a QS 12kW hub motor, QS is really reliable once you passed the first month of use, plus their motors can take way more power than what's advertized.
Pretty sure the 12KW can take 60 KW without any problem. Friend of mine got the 8KW and reliably drops more than 35-40KW in it. Plus they have insane amounts of torque.

Max speed will mostly be constrained to your battery voltage. To give you a ballpark idea, 72V should give you about 80-90kmh, 84V around 100-110kmh , etc.

Just ran through your post on your own Ninja build...Gives me HOPE! lol It's really NICE!!! and beating reg sports bikes is just so satisfying!

Is the QS 12kw too much? since they can be over powered, I saw yours had a 3000w one, I'm curious to know the wheel size you went with. (diameter & width) I was planning to go with the 17" * 6" b/c from what I read that's the Ninja's original rim size.

This is the one I'm thinking https://www.aliexpress.com/item/32982641447.html?spm=a2g0o.cart.0.0.72633c003xy9LR&mp=1
I spoke with the seller and they can bundle it like this, So I think all that's left is the batteries... https://www.aliexpress.com/item/32791241903.html?spm=a2g0o.cart.0.0.72633c003xy9LR&mp=1


Most likely I'd like to be able to go up to 110 kmh(7S 84v) , even though I most likely will not really hit it, more so to not be Full Throttling it all the time...so i guess I don't need such a powerful hub motor....the one I was looking at could go up to 144v, CRAZY! based on your numbers above...144v should go about 160-170 Km/h (is that possible?)

 

[Dui ni shuo de dui]

Is the QS 12kw too much? since they can be over powered, I saw yours had a 3000w one,

I'd say if you have the money then go for it, a better motor gives you more margin for evolution and also more reliability. The downside might be weight, I think the 12kw is real heavy. An other good compromize is the 8KW, as I said in my previous post, we installed one on a friend's bike and it is plenty powerful, so far it's been reliable, and it is not too heavy.
My motor is weird, it is rated at 3KW but it takes a beating like no other motor, I don't know why, always been a mystery to me :lol:
Also if you live in Florida, it is quite hot there so having a bigger motor might help with reliability, since if you don't push it to its maximum power then it won't heat much. Also, I remember that one version of the 12KW motor is watercooled.
Anyway, a good motor is always a smart investment.

I'm curious to know the wheel size you went with. (diameter & width) I was planning to go with the 17" * 6" b/c from what I read that's the Ninja's original rim size.

Mine is 16 inches, which I really don't recommend you.
The advantage of having a smaller wheel is that you get more acceleration for the same power, but the very big inconvenience is that it is super difficult to find nice tires at these size. There's basically no sport bike that runs on 16 inches, so you're stuck with very heavy cruiser tires, or some scooter tires. The only good compromize I was able to find was a Michelin city grip, but it was really hard to find in 16inches, there was litterally only one shop in China that had it.

This is the one I'm thinking https://www.aliexpress.com/item/32982641447.html?spm=a2g0o.cart.0.0.72633c003xy9LR&mp=1

Yeah that's a great motor. Careful though, the page you directed me to is showing the 10KW, not the 12KW one.
Also before ordering don't forget to ask them to include the temperature sensor, they don't always include it if the customer doesn't ask.

I spoke with the seller and they can bundle it like this, So I think all that's left is the batteries... https://www.aliexpress.com/item/32791241903.html?spm=a2g0o.cart.0.0.72633c003xy9LR&mp=1

Seems a bit weak to me, you can fit a much more powerful controller than this. The controller you showed me is similar in performance to what I'm using on my bike (500A phase peak power, 200A battery). It's decent power, but if you invest on such a powerful motor then you should go for a more powerful controler too.

Most likely I'd like to be able to go up to 110 kmh(7S 84v) , even though I most likely will not really hit it,

Well it's easy to reach 110kmh believe me, these things accelerate fast! I hit 110 everyday and I live in a busy city with crazy trafic, so I guess in Florida it will be even easier!

more so to not be Full Throttling it all the time...so i guess I don't need such a powerful hub motor....the one I was looking at could go up to 144v, CRAZY! based on your numbers above...144v should go about 160-170 Km/h (is that possible?)

With flux weakening in theory yes, but at some point the aeerodynamics become a huge limiting factor and that's when you need more power. With 144V I'd say a 140-150km/h should be realistic. But you have also to remember that finding a controller capable of such voltage will not be as easy as finding one good for 72V, high voltage controllers are expensive.

 

[eldan]

Seems a bit weak to me, you can fit a much more powerful controller than this. The controller you showed me is similar in performance to what I'm using on my bike (500A phase peak power, 200A battery). It's decent power, but if you invest on such a powerful motor then you should go for a more powerful controler too.

I could be mistaken, but 200A @ 72v =14,400 Watts Its rated at 8kw, I guess that's why they can handle a beating like you mentioned earlier.. I couldnt find a larger one, Ill ask if the supplier has & keep looking. I'll also be asking for the motor temp sensor as well

Mine is 16 inches, which I really don't recommend you.
The advantage of having a smaller wheel is that you get more acceleration for the same power, but the very big inconvenience is that it is super difficult to find nice tires at these size. There's basically no sport bike that runs on 16 inches, so you're stuck with very heavy cruiser tires, or some scooter tires. The only good compromize I was able to find was a Michelin city grip, but it was really hard to find in 16inches, there was litterally only one shop in China that had it.

the unaccounted variables....they are the worst... I almost did that with the rim size. (I measure the tire 6 inch, but I didn't pay attention to the mushrooming effect from the motorcycle's rim to tire. I don't have the exact size, but from what I gather, the standard is 3.5" - 4.5" rim lip that hold 6" wide tires.. for Ninja 500 '09.
Long story Short, I didn't finalize the order, they are on holiday until oct/8. when they're back I will order the 3.5 inch size & Save like 40%.
In the meantime, I'm hunting the best Batt option.
Lion or Lifepo4...hopefully I can have it all ready before the holidays..