999zip999
100 TW
Best off a 52v battery and see what brakes first. We melt motors and blow up controllers here and then move oh.
Hub Motor Upgrade 500W to 750W
- Thread starter devlin016
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Dauntless
100 TW
People are trying to tell you that as you put bigger and bigger motors on the controller, it'll draw more and more amps, which is what makes it so hot. Can your controller survive having a 1000w motor sucking, I don't know, 40-50 amps at times? So the bigger and bigger motor on the same controller is not a good idea.
Nobody is going to tell you to expect the controller to survive. But we haven't connected these things ourselves, so we have no proof there's a problem. That's the best you're going to get.
Nobody is going to tell you to expect the controller to survive. But we haven't connected these things ourselves, so we have no proof there's a problem. That's the best you're going to get.
maanebedotten
100 W
I dont think any of the geared motors will give you what you want. They are light and small, which means they can not soak up and shed enough heat.devlin016 said:
Going with a slower motor and running it on higher volts and lower amps for the same 22mph top speed and accelleration you have today is a little bit more efficient and might just be enough to get by without overheating, but that is a big cost for a very small increase in performance and it still might very well overheat.
You are surfing the very limit of what a small geared hub can do, so I think you need to look to the bigger and heavier direct drive motors.
devlin016
100 mW
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- Jun 29, 2020
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yah im aware of the risks for the controller ill replace it as she blows or later on with the battery I do understand all of that and honestly I was thinking of the idea in my head of geared rear hub and maybe a direct drive hub on the front.. and they both the same connects.. i forget what there called exactly but there water proof connects I guess. and ill just switch the connects from the front or the rear... that sounds pretty sweet... a direct drive e bike and a geared e bike... i wouldnt run them both nor would I want to... id just switch the connects.
There's not much point in carrying two motors around if you're *not* using them both at the same time.
The reason (in your case) to use two is to reduce the load on either one, so there is less heat generated in each one, and less risk of damage or problems.
But you can do whatever you want; it's pretty obvious at this point you have your own ideas of how things work, so don't let us stop you from learning thru experimentation.
The reason (in your case) to use two is to reduce the load on either one, so there is less heat generated in each one, and less risk of damage or problems.
But you can do whatever you want; it's pretty obvious at this point you have your own ideas of how things work, so don't let us stop you from learning thru experimentation.
devlin016
100 mW
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seems like im not the only one stubborn here. i understand there will be overhead in carrying 2 motors and just using 1 at a time. but dont you think that would be worth it? why wouldnt it? I dont think the overheard would really be that bad. how much do these motors weigh? cant be that much. and im also thinking whenever the geared hub over heats why cant i just switch the the direct drive hub and that one for sure is built strong enough to not over heat..... I just dont see any how in the world id fit 2 controllers on my bike without it being ugly.....I get alot of people even asking me about ebikes and saying mines not ugly....i need both worlds i know thats frocked up but it is what it is. my girlfriends ebike everything is inframe female frame street tires 250w... its really good looking..... i cant just load my bike up with stuff.
maanebedotten
100 W
Ill let you in on a secret: most participants on internet forums are stubborn as f... :lol:devlin016 said:
It takes some stubbornness to partake in the usually futile activity of convincing people on the internet that they are wrong. And when you boil it down, that is the essence of most internet forums.
Stubbornness is not inherently bad though. People being stubborn enough to find ways do things others say is impossible is one of the driving forces behind humanitys development. Most, of course, fail in their attempts to do "the impossible", but every once in a while someone succeeds and creates a breakthrough in whatever field they are working in due to their stubbornness.
maanebedotten
100 W
The biggest geared motors weigh about 4-5kg, direct drives 6kg and up. The weight is not what really matters in this case though. The geared motors have a clutch that makes it possible to spin the wheel without spinning the motor. DD motors do not. A disconnected direct drive motor will put drag on your front wheel (aka cogging), effectively working as a brake. This will put an even bigger workload on your rear motor making it overheat even faster. Unless you plan to power it all the time, a direct drive is not a good idea.devlin016 said:
I dont mean to be rude, you are probably a smart guy, but due to your lack of general knowledge on the topic you make a lot of assumptions that are just wrong.
The way I see it, there are 2 ways to build a successful ebike. The cheapest, most painless way is to copy a build that has proven to be successful under similar conditions as yours. The harder, but oh so much more rewarding way in the end, is to take the time to actually learn how stuff works before starting to design and build. Even after studying for months you can still expect to end up with a bin of parts that turned out to not work as planned before you have a bike you are happy with.
Dauntless
100 TW
maanebedotten said:
Stubborn really isn't the right word. People are being asked to share their experience, then this person who claims none of his own argues with it. Nobody is supposed to agree with things they know are wrong. This isn't MSNBC.
devlin016
100 mW
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- Jun 29, 2020
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- 40
man im just asking questions im not arguing and i have been researching ebikes for the last 10 years before they were popular back when they had to be ugly. your right about the direct drive on the front and geared on the back... forgot all about the drag direct drive gives vs geared. i thought it wast just about weight at first. its not that I dont know these things or I havnt read them its just I forgot some things I guess because I dont practice the knowledge everyday. i do understand how that sounded moronic though. i guess just take what i say with salt if it sounds dumb theres a not so dumb excuse I have lol. but considering my options i think I want to stick to geared then maybe 1kw on front and back? and I switch the quick disconnect in between them both? how does that sound? I think I remember reading 36v gives the best efficiency so if i can id like to stick to 36v if I have to go up I will slowly not just run it at its highest. and for being a 800$ bike ive had it for about 2 years put lots of miles on it and im not really a peddling kinda guy I just like the option... ill tell you guys what the odometer says next time I see it
maanebedotten
100 W
Feel free to swap stubborn for adamant or persistent if you prefer.Dauntless said:
Usually I would not bother to try and help someone who asks for advice, then totally disregards the advice he gets, but I am too stubborn to give up on this one yet so I will keep telling him why his ideas are bad until he sees the light or gets mad and gives up.
maanebedotten
100 W
So you want to run one motor until it overheats, then stop, get off your bike, switch to the other motor then rinse and repeat?devlin016 said:
Besides abusing both motors reducing their lifespan, that really sounds like too much of a hassle.
If you want to stay with geared motors, and want to run two, you should run them both all the time. You might even be able to fit both controllers in your existing box, sub 20 amp controllers are about the size of a cigarette pack. If it does not fit, get a bigger box or a nice bag to keep the "prettyness".
Stop looking at the power ratings on the motors, the advertised numbers have little to no relevance to what the motor can actually take without overheating. Since most geared hubs have similar construction the only things that matter is size and weight, a bigger motor can shed more heat due to larger surface area, a heavier motor will take longer to heat up than a small one.
The only reason 36v can be considered more "efficient" than 48v is because it gives a slower speed. Given the watts stay the same higher volts is more efficient due to less amps.devlin016 said:
In your case I would stay with 36v unless you are going to change the battery anyway, otherwise the cost is too high for little benefit.
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Which is why you are frying your motor.devlin016 said:
Do you know the specs of your battery? Can it deliver more than 20 amps?
devlin016
100 mW
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- Jun 29, 2020
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- 40
okay now were talking dude. I might have to get a bigger controller box but I would want it the same style and position as my existing one. I already have this motion alarm box thing in my controller box.. works really well picks up on any vibrations on my bike anywhere and it has a key fob makes my bike look like it has a alarm. I didnt know 20amp controllers were so small.. that makes me think maybe a bigger controller box make this all come together.... Im not sure what kind of cells or bms my battery has. I do know I paid extra for there extended battery I think it had like 2 extra amp hours. how would I find this out??? I defiantly dont wanna put 2 batteries on my bike so everything must be drawn from 1. but if my understanding is correct each motor will be working at half load because there sharing it with each other. so will the total draw on the battery be that bad? and do you think this would improve my total speed? what would riding be like?
devlin016
100 mW
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I dont know what cells this pack has but I have put alot of cycles on it and I dont feel like the chemistry is starting to give... I feel like its close to performing same as when I purchased it. and I have putt this pack through stress for sure.. with hott 90 degree summer riding and below freezing winter riding..with all kinds of terrian changes.. i bet the controller draws everything it can most of the time...they claim this is a beach snow mountain bike so I just had to see for myself lol... I learned hard tailing it on crazy trails is defiantly dangerous and atleast breaks your back. honestly this hard tailing shit sucks.. these pot holes make me vibrate all over the damm road i look like a goof ball. im about to lock tight my bike so it dont rattle apart lol
maanebedotten
100 W
You will not be able to get much more top speed, but if your battery can do more than 20A you can potentially get better speed up hills in addition to better accelleration. Is your battery marked in any way? Any labels? Can you find a link to your exact battery on the manufacturer site?
At full throttle your controller probably draws the full 20A until you reach 18-19mph, then drops to 18-19A at full speed. Its amazing that it has survived at all honestly.
With 2 motors you have to make sure the total draw never exceeds you battery capability so you can at least do 2x10amp giving you comparable performance to what you have now without overheating anything. If your battery is capable of 30A you can get a considerable performance increase.
At full throttle your controller probably draws the full 20A until you reach 18-19mph, then drops to 18-19A at full speed. Its amazing that it has survived at all honestly.
With 2 motors you have to make sure the total draw never exceeds you battery capability so you can at least do 2x10amp giving you comparable performance to what you have now without overheating anything. If your battery is capable of 30A you can get a considerable performance increase.
maanebedotten
100 W
The bms will just shut off your battery when you exceed its current limit. If the pack is designed well this will happen before there is any danger of damaging the battery. If you open the battery you can probably see the exact cell type used, the bms may or may not be marked with its current limit. I would not expect to be able to pull more than 25 to 30 amps max without risking damaging the pack. If you want to go to 40 amps, you almost certainly need a new battery, and might as well go to single motor direct drive. Running 2 small controllers at 20a each inside a box will probably overheat the controllers anyway. To have a reliable system you can not push any component close to its limits. My rule of thumb is to keep my peak power within my components continuous capability.devlin016 said:
devlin016
100 mW
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- Jun 29, 2020
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the bike shop will measure my dropouts before he installs my hub... if its off i will not bend my frame wtf....risk here is wasting money not damaging my bike. I guess 10 amps each controller is what its going to have to be... do you think that would make performance suffer any compared to now? and i know you really shouldnt work anything to full capacity.. there should be left over room for overhead.
maanebedotten
100 W
I do not know enough about efficiency scaling to say, but would assume a little bit of loss.devlin016 said:
How much money are you willing to spend on this? Unless you can do most of the work yourself it is going to be quite expensive. Lacing and truing a wheel properly takes quite a bit of time, running the wires in a way that is not ugly also is time consuming. Programming and/or modifying controllers to work well in a 2wd configuration is a bit more complicated than just installing a motor kit where everything goes together out of the box. Few people have enough experience with this to get it right without spending a lot of time testing and tweaking. Having a bikeshop do all this for you will probably cost more than your bike, and there is no guarantee you will be happy with the result.
maanebedotten
100 W
This probably means that the motor fits 190mm dropouts, but comes with the spacers needed to make it also fit 195.devlin016 said:
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