Hello folks, I've been getting into electric motors and such for the past several months, and I have some questions I'd like to ask directly. I've been reading tons of posts, scouring the internet for motors, controllers, etc and trying to learn some things. But I feel at this point I have some questions that I need some direct feedback on. I have a little experience with bigger RC motors, but I'm still fairly new. I am not new to building my own contraptions though, as I've built an on-road 2 person trike, and an offroad buggy. Seeing as electric is the future, and the benefits it brings, I'd like to start transferring to electric though.
So I have a few things I'd like to try to convert to electric. The first two are my motorcycle and ATV. I am still in the planning phase, but I would at least like to have some possible parts such as the motor, etc, scoped out. My current motorcycle that I ride is a CBR 600, and the ATV is a Honda 700xx. Both are very high performance machines, but deliver power in different ways (4 cylinder vs big single cylinder). I may go with a different motorcycle frame for my electric conversion, but I'm still figuring that out. So anyway, I have a handful of questions, if anyone could answer some of them, that'd be great!
After digging a whole ton, it seems to be there's not a whole ton of motors to choose from. (Correct me if I'm wrong). When building a motorcycle size vehicle, I have a plethora of motors to choose from donor vehicles, but electric doesn't seem to be the case so much.
1. The only feasible motors I can find are the ME (motenergy) series of motors and QSMotors. There are a few others, but they are either very expensive, or there isn't much information about them. These two look like my only good options, am I missing any others?
2. Are the QSMotors quality and powerful? I am hesitant replacing a good working gas engine with something possibly cheap and junk from China. Most things I've read say they are decent though? Do the hub motors last a long time?
3. I've read a lot saying the QSMotors are way under-power rated on their website, saying they can push WAY more power. Is this true?
4. I am considering a hub motor for my electric motorcycle conversion. Although based on their power numbers, I am worried that I will be very underwhelmed with their power output, vs my current CBR600. I don't expect to go 150mph, but I would still like some awesome acceleration. Would the QSMotor 8kw hub motor or 12kw hub motor be a turd compared to the CBR, and will they put out an impressive amount of torque and still accelerate fast?
5. Is the un-sprung weight a big deal for a hub motor on a motorcycle? I imagine since it's not an offroad vehicle, that it shouldn't be that big of a deal.
6. For the ATV, I am considering an ME or ME motor. However I am seeing that QSMotor offers a 4kw mid-drive and an 8kw mid drive (can't find as much info on the 8kw though). Assuming they can be pushed well over this limit like some people have said, does anyone have any recommendation on the ME vs QSMotor comparison here? I get the impression that the ME's are better quality, but they are also a lot more expensive. Again, the 700cc ATV is pretty beast, so I'd like something that can come at least fairly close and won't be a disappointment. But I also don't need something that is absolutely crazy overkill.
Additionally, if you have any more recommendations on motors or setups that I could consider, please let me know. I'm sure I'll have some more questions. Thanks!
Thanks for the info! Good point on the re-selling, I probably wouldn't plan on selling it anytime in the foreseeable future, but I suppose it is something to consider.
Hmm, so you say you like the 12kw hub motor, but you think it would still perform substantially less than a zero? I realize the biggest, baddest, zero is something like an 80kw monster, but you still think it would underperform even to their lower powered, 30kw stuff? I suppose I'm really looking for a descriptive answer on just how strong the QS hub motors runs. I don't want to put a scooter motor in a sport bike frame. But again, I don't fully expect it to perform like a 600cc race bike, but I'd still like it to be a thrill to ride.
As for cost, maybe I am vastly overlooking something, but it looks to me it would be a lot cheaper for me to make a bike/ATV myself. I just doubled checked, and there's hardly any used market on used zero motorcycles within 150 miles of me. Even so, the cheapest one(s) are around $6k and they're from like . So definitely no goods deals there.
But as for the cost, here is the hub motor + controller + various other parts. https://nl.aliexpress.com/i/.html?spm=a2g0z..0.0.248fc1f4hOxCIX All for $. Here are batteries for around $2.75 a pop. https://www.ebay.com/itm/100X-Model-3-Tesla-NCRA---mAh-Battery-3-7V-With-Charger/?hash=itemd063f1:g:hbMAAOSwYV9e2Xs- This equates to around $150 per kwh, or $1,500 for a 10kwh pack. I'm sure there are other various parts for the battery, and the BMS, but would it really much more? That'd only put me at around $3k, but we'll just throw in another $1k for various parts and just to aim a little high. Which would put it at $4k. I already have a few bike frames, so that'd be more-or-less free. Is there something I'm missing? Because I'm still semi-new to this, so maybe their genuinely is something I'm missing.
Also, if anyone has any more info regarding the other questions, such as the stuff related to the ME motors, still curious there.
The QS hub motors are very capable, some have achieved crazy fast performance by using monstrous controllers such as the large Kelly and Nanjing controllers.
https://youtu.be/ZU7MLqmpUhA
But bare in mind this was achieved using a scooter which probably weighs two thirds what a 600 would weigh and wouldn't be able to sustain that sort of power for a mountain cruise etc but 0-60 in sub 4 with a decent top speed should still be attainable.
Secondly, I do not recommend building your own pack if you haven't built any sort of battery before on a cell level, it is not an easy task and in my opinion it should only be done if you can do it correct otherwise you'd be throwing money at a time bomb that you can't reuse or sell in the future.
If you truly want a super sport 600 looking bike that performs and feels the same I don't personally suggest the hub motor, motorbike manufacturers work their ass off shaving grams of unsprung weight from the swing arm and wheels, a 30-40kg hub is definitely going to throw things out of balance. Hub motor users are going to be at my throat, they are great in many ways, taking curves at high speed definitely is not what they were designed for.
As for the costs you're mentioning they really are best case scenarios that even experienced EV builders would struggle to meet. Those are reclaimed cells so while being "unused" is a form of corner cutting, and as I mentioned earlier, not worth building your own pack if you don't do it correct, copper plates utilizing cell level fusing, your $ 10kWh pack has now nearly doubled in price assuming you're using the reclaimed cells anyway.
If you truly want to build a 600 super sport equivalent then you should look at the Zero SR/S and Energica Evo to copy or for inspiration.
That hub motor controller combo will maybe achieve Ninja 400 performance, even that is optimistic. As I said, the hub will take the abuse, finding a controller capable is no easy feat, especially when it comes to cost.
These two bikes have 80kW and 105kW mid drives respectfully, the best Motenergy motor such as the ME & ME claim to be 60kW capable yet nobody seems to have achieved that because of their poor design and efficiency.
That essentially leaves you with trying to source a used 75-7R, 75-10 or Energica motor and a $+ controller to power them.
To conclude, for $4k in parts you can achieve 400cc performance, even then its optimistic in both cost and performance.
therobby3 said:
Hmm, so you say you like the 12kw hub motor, but you think it would still perform substantially less than a zero? I realize the biggest, baddest, zero is something like an 80kw monster, but you still think it would underperform even to their lower powered, 30kw stuff?
IIRC, the Zero motor weighs about as much or more than the QSmotor hub, but the Zero motor is intended to spin faster (middrive vs hub), so it makes more RPM that then gets converted to torque via the reduction to the wheel itself...while the QS motor has to use less motor mass to try to do the same thing directly without the reduction...so the Zero motor is going to be capable of more power in it's application than the hub.
The QSmotor is also not designed to be a 30kw motor...but the Zero motor *is* (and could probably be run as much harder vs it's spec, as the QSmotor, so if "abused" similarly, would probably still make more power).
To get the same kind of torque out of a hubmotor that a middrive with reduction can do, you need a bigger more massive heavier hubmotor that will more greatly affect the handling/suspension of the bike it's attached to than that one already will, and it will take a bigger controller and battery to do it, because those have to push more current thru the motor to do the same thing.
(It's also possible to go higher voltage rather than higher current, but you'd have to get a hubmotor wound to do the same top speed at the higher voltage to get the better torque at that lower current / higher voltage; QSmotor will probably make anything you want...but it's not off the shelf).
If it is helpful, you can go to the http://ebikes.ca/tools/simulator.html and read the entire page to learn what evertything is and how ot use it, then play wiht different systems under various conditions to learn how different things interact. YOu can even use a hubmotor in system a in the wheel as normal, then in system b stick it as a middrive with various reduction ratios and different battery voltages, to see how it would perform in either case. It doesn't matter that most of the stuff there is lower power bicycle stuff--the principles are exactly the same.
Big powerful hubmotors weigh a lot, but they're relatively cheap, and they're used in "common" "cheap" chinese motorcyles because they are cheaper and easier to build bikes from than a good middrive system, and have much lower maintenance costs (which may also mean less warranty claims, if there is even a warranty in the first place).
But for the size and weight, the middrive is going to buy you more power and better handling than the hub will, for the same bike otherwise.
As for cost, maybe I am vastly overlooking something, but it looks to me it would be a lot cheaper for me to make a bike/ATV myself. I just doubled checked, and there's hardly any used market on used zero motorcycles within 150 miles of me. Even so, the cheapest one(s) are around $6k and they're from like . So definitely no goods deals there.
I generally prefer to assume everything will cost much more than I first think it will, and take longer to do. I'm almost always less disappointed in the results that way.
The guesstimates below aren't based on any specific stuff, just general guesstimates for something that might be able to do the same thing as the used bike or better, as I don't know enough about exactly what you expect from the system and under what specific conditions to determine necessary battery capabilities and capacity, or power needed by motor to do them, etc. I also don't include anything that would already be on the converted bike, nor do I include the stuff you'd have to machine to mount the new stuff on, or housings, or battery enclosure, etc. Or the stuff that you'd need to manufacture if the bike being converted uses the engine as a stressed frame member, when you remove that.
Depending on exactly what you expect out of the system, and what you need it to do, you might pay more than half that cost just for most of the parts to build a good battery that will do what you want. The battery is the very heart of the whole system, the most important piece, and must be able to supply anything that is ever asked of it without complaining in any way, and has to do it for however long you ride under all conditions, and however long you own and use it. People very often cheap out on the battery, because it's the most expensive part...and then the system doesn't do what they wanted, etc.
A good controller might cost a fifth of it, perhaps with the motor, possibly double that with shipping costs if shipping keeps increasing, depending on where you are. But I think that the motor and controller might *each* cost that by themselves.
Tools and test equipment may cost you another fifth of that, especially if you're building the battery yourself too, depending on how you build it.
Wiring, connectors, etc may cost up to a few hundred dollars depending on how much of it you have to do.
Taxes and import duties are likely to be quite a lot on all this stuff, and shipping; hazmat costs for battery stuff may bring costs way up on those things, if the sellers are shipping them legitimately and properly marked/etc.
Since everything I've built so far is for lower power and lower speeds, sometimes my "intuition" on bigger stuff is wrong or misleads me, so don't take anything I say above as complete gospel.
therobby3 said:
1. The only feasible motors I can find are the ME (motenergy) series of motors and QSMotors. There are a few others, but they are either very expensive, or there isn't much information about them. These two look like my only good options, am I missing any others?
As far as I know, for hub motors that pretty much sums it up. There are a few other ones here in China but I don't know if they sell abroad.
Not as good as QS anyway from what I heard.
therobby3 said:
2. Are the QSMotors quality and powerful? I am hesitant replacing a good working gas engine with something possibly cheap and junk from China. Most things I've read say they are decent though? Do the hub motors last a long time?
As for all things, it depends. In my experience, they are good and reliable for the most part, but some people have issues with the hall sensors sometimes. But that might be the fault of their controllers not regulating voltage properly, can't say for sure this is due to the motors themselves. Anyway, it's not too difficult to fix, plus the motor comes with two sets of hall sensors from the factory.
I had one bearing gone bad once. Replaced it, no biggie.
From what I've seen, if the motor is bad it will break very quickly, like in the first month of use. If it goes past the first months, then it usually lasts for a very long time. I haven't burned one yet, and I'm not sure I know anyone who did.
therobby3 said:
3. I've red a lot saying the QSMotors are way under-power rated on their website, saying they can push WAY more power. Is this true?
Yes, the peak power can be much, much higher than what is advertised.
To give you an idea, I have a W hub motor on my bike, and I power it with a 16 000Watts controller. Been like that for around 3-4 years now, I drive the motorbike everyday to go to work, the motor is still happy.
My previous motor on the scooter was a W one, paired with a 10-11kw controller. Same here, the battery died after 4 years but the motor's still good.
Some of my friends were even crazier than this with their W motors.
To be honest, I don't know what is the limit. On my current build I'm using a KLS controller paired with a W QS motor, so if the motor survives that then I guess it can survive anything. I sure hope it will, cuz I don't want to actually find this limit. :lol:
Keep in mind that they are peak power under-rated, but if you plan on using this amount of power on a continuous basis (like running at 50KW for a straight 15 minutes without any stop) then I'm not certain the motor will be able to bear it. The kind of situations where this would apply could be driving full speed on a freeway for a long time, or climbing a steep mountain for many miles. Not sure it would cope well with these.
therobby3 said:
4. I am considering a hub motor for my electric motorcycle conversion. Although based on their power numbers, I am worried that I will be very underwhelmed with their power output, vs my current CBR600. I don't expect to go 150mph, but I would still like some awesome acceleration. Would the QSMotor 8kw hub motor or 12kw hub motor be a turd compared to the CBR, and will they put out an impressive amount of torque and still accelerate fast?
I never drove a CBR, so I can't objectively say how it would compare. But I'm sure it's won't be ridiculous.
I'd say that the CBR should beat it, but in order for that to be true it would need to rev high and to play with the gears, while on the electric bike you'd just have to turn the throttle.
It is plenty of fun to ride, I think that matters much more than just theoretical acceleration in ideal conditions.
But If you're really concerned about the pure numbers, then you can have a look at Rovi's thread, he was using a QS hub on his dragster motorbike and I think the times he got weren't ridiculous:
https://endless-sphere.com/forums/viewtopic.php?f=12&t=
Wasn't cheap though.
therobby3 said:
5. Is the un-sprung weight a big deal for a hub motor on a motorcycle? I imagine since it's not an offroad vehicle, that it shouldn't be that big of a deal.
Nope. In my opinion it doesn't matter much for 99% of drivers. Might matter if you're planning on beating the best time on the Nurburgring, but realistically you'll drive this thing on open roads, so who cares if you lose 0.02 sec in a turn? People will talk about all sort of stuff like center of mass and whatnot, but most drivers are not able to reach anywhere near the limits of current sportsbikes, especially on open roads, so make yourself a favor and leave all that stuff for professional pilots :wink:
And If you're really concerned that much, then just invest in a really good rear shock. Won't make it as competitive as a motoGP, but it will help compensating a bit for the added weight.
It's all a matter of compromizes, sure it's not ideal, but what you lose here you'll gain it in battery space, controller space or whatever your plan is.
The only thing that is not so great for us homegamers is the ride quality on bumpy roads, so if the roads you're planning to drive on are in really bad shape that isn't ideal. Hub motors really don't like potholes, which can destroy the rim... problem is here the rim is actually the motor, and as far as I know QS don't sell the rim alone. So, to protect it, it might be a good idea to use a heavier/thicker tire made for a heavier bike. That being said, I haven't seen a 16 or 17 inches rim being damaged on a QS motor yet. Have seen several on smaller diameter ones though.
Thanks for all the info!
@c70r Yea, I suppose for the bike I would be aiming for something closer to maybe a Ninja 500. I know the peak horsepower on the pure race bikes is nuts, so trying to make an electric motorcycle with that powerful of a motor would probably be overkill. I definitely wouldn't be trying to make something similar to the sr/f, the 80kw monster. Probably something closer to their mid or lower tier bikes would be good enough. It's good to hear that people seem to be agreeing that the QS motors are high quality.
The Zero motors do sound like a great motor. Unfortunately there's hardly any used Zero motorcycles on the market, and I really couldn't even imagine how I would find just the motor for one. Their definitely isn't a single one on ebay, and from what I read it sounds like you can't buy one directly from them. So that options probably mostly out. =/
Glad to hear you think the quad conversion is good though! I agree, I think the quad would benefit the most. And I really like the idea of it being quiet, and not making neighbors and such mad. The ME says 44kw peak on one website I am seeing, which would be 58 hp peak, and probably a ton more torque then the already super torquey 700xx. So I wonder if that may even be overkill?
@amberwolf & Dui, ni shuo de dui
Good points. Seems like a tough decision to make on hub motor vs mid drive then. Typically when I've been creating buggies and such the last few years, part of the fun is trying to make the best performing machine I can. Which in this case really leads me to wanting to use a mid-drive. However the cheapness, easiness, and extra room of a hub motor can be pretty attractive. Cool to hear they can take a lot more power though. I guess I can get a little torn on building something slower and economical, but also not wanting to miss having something fast and fun. So that's where I want to kinda find a mid-point.
lol, to be honest it is a little demotivating hearing about all of these costs. Although I guess that's the reality. It seems we're right on the cusp of electric starting to take over. So part of me thinks maybe it'd be a better idea to wait a few years for things to advance, and maybe drive the cost of everything down as well as have more options for parts to buy. But at the same time, that could be an endless cycle of waiting.
It mostly comes down to...do you want *something* now? If so, you can go for the low-end or mid-range version of stuff, and upgrade later the things you find that don't do what you want, as you need them to.
I have built a bunch of different things to get me around and do different things, and I keep making them bigger / better / more useful in whichever new way I find I want them to be for me. (I'm working on designing yet another right now :lol: ).
But I have found that if I don't do anything else the high-end of things, doing the battery in a way that will later support anything else I might want to do with it is cheaper in the long run and makes the stuff I am doing *now* work better than a "cheaper" battery would.
The problem with batteries is...if you don't know anything about batteries, and haven't built some to make mistakes with and learn from , then building your own especially for high performance requires a fair bit of research and time--first to learn how to know what it is the system you really want to build will require of a battery. Then about what kinds of battery parts support those needs. Then the best way for your specific usage scenario to physically construct the battery, from enclosure and shape to interconnect methods, protections, etc.
I, for instance, went the route of easy-to-bolt-together ex-EV cells, because I've seen some of the disasters people have ended up with for packs that can do the sorts of things I need one to do, when built on the budget scale *I* have to work with. :lol: And I also know that if a project is going to take too long, there's a high likelihood I'll never finish it (I'll get tired of working on it, and at that point it's very unlikely I'll ever get back to it because I have so many other things to do). And I don't really have a requirement for a particular shape or size of pack, just that it has to do what I need it to do, which doesn't limit me nearly as much as with most people, who have a specific space they have to put the pack in (whereas I can basically build the bike or trike around the need for a certain shape and volume for the battery). My main limitation is cost--I simply dont' have much money to throw around at anythign that isn't a good direct solution to a specific problem, right now.
Anway, all that rambling aside, I meant to say that it is probably cheaper for you to buy a good prebuilt battery that fits your needs and physical requirements, than it will be to build one from parts, just because of all the missteps that nearly always happen in the learning/building process, and the design changes that may have to be done halfway thru, etc. And the cost of all the battery-building and testing tools, and your time learning and doing all that stuff. (personally I find all of that invaluable in other ways, but most people just want to build the thing they're building and ride it and get on with it. Most don't have much of a use for all that stuff and info outside of using it once to make what they think they want).
But, if you don't mind all the time researching and reading a bajillion battery build and troubleshooting threads :lol: (and other websites , etc) then you may be able to learn enough to build an even better battery than you can buy, for maybe the same money (or a little more)...it's just a lot of time and work.
All the other stuff for a conversion...especially hubmotor...is pretty easy, compared to designing and building a battery. Most of the other stuff doesnt' have the destructive potential that a badly built battery does, and most of it doesn't have nearly as many parts that go into it, or as much labor and time.
If I werent' looking for super high performance/power, a hubmotor build is fairly easy. And, as you note, it leaves you more room for stuff in the frame, etc (whcih is the other reason most of the cheap "motorcycles" use them--more room for battery, which is pretty important since most of them are using the cheapest batteries they can get, so ti takes a bigger one to do the same job).
The thing you first have to decide is what exactly you want the vehicle to do for you. Until you define that completely, it's not really safe to decide on a parts path.
@MJSfoto
Fortunately, I have both a welder and a 3D printer, as I do really like to create and build things! Thanks for the suggestion on the hub motor.
@amberwolf
Thanks for the feedback! Perhaps it is a better idea for me to start smaller then. I have a smaller Honda XR80 dirtbike, I think I will go ahead with converting that to electric first. I will work on building my own battery pack, as I think the experience will be a great thing for me. I've been reading a lot about building one and I think I understand a lot about what needs to be done to build one. Now I just need to get the actual experience of building one, as you can only read so much before you need to just do it yourself. I hear ya on the big project thing After my last few of my big gas powered projects that took a whole lot of work over an entire winters, by time the projects were nearing completion I was getting a bit burnt out from them. So maybe smaller will be better, until I get a bit better grasp with building electric things. Plus I won't have to throw around anywhere near as much money. I danger of lithium ion batteries does sound a bit scary, so I'll try to be safe about it.
I keep seeing a lot of articles about solid state batteries and it makes it sound like they will be out soon (within the next year or so). Almost makes me want to wait until they come out to do anything big project with batteries. But it's also hard to tell if these news articles about them are just hyping them up more for the sake of an interesting article, or if they will really be that great and out that soon.