Hub Motor Upgrade 500W to 750W

can anyone help me upgrading a rear fat hub motor? my manufacturer gave me a shit reply when I asked them if a certain motor will work or not... they simply said we dont offer upgrades anymore.... when that wasnt even the question I was asking.....I have my bike specs and possible hub motor replacements picked out I know my controller will work just need to know if the sizes are correct. I have a bike shop that will respoke it and install it for me but other than that they dont do ebikes really atleast not this type of customizing. i hope someone is knowledgeable enough to help me.

my bike is a ecotric 26 snow beach fat tire heres the link https://www.ecotric.com/collections/frontpage/products/26-fat-tire-blue
and i wanted to upgrade it to this motor heres a ebay link https://www.ebay.com/itm/Bafang-48V...r-Hub-Motor-190mm-For-Fat-E-Bike/292541324824

i know my controller will work with it. just worried if sizes are correct or not. I have a local bike shop that will respoke it and install the motor for me.... can someone knowledgable please help me if this motor a suitable match? I want to upgrade as I can make this one overheat . My controller will only let me push about 720W so a 750W will be slightly underpowered which sounds great to me.

https://www.ebay.com/itm/48V-1500W-Ebike-Threaded-Brushless-Gearless-Rear-Hub-Motor-for-Electric-Bicycle/172223877753

The thing to think about is if you're getting enough improvement to be making the effort. "Slightly underpowered" is additional overheating. Oops. There is no guarantee the controller will survive this.

I just think you have to double the power for it to be meaningful, triple is even better.

when the controller blows ill replace it. I want to upgrade motor for now.

If you use the same controller, the new motor will not give you more power. It might give more torque/lower speed or less torque/more speed depending on configuration.

To get more power from the motor, you need to feed it more power. 720 watts is 720 watts no matter how "powerful" a motor you send it to.

You can probably push your current motor harder if you mod or change your controller. Check what max current your battery will provide to see if you have headroom for more powerful controller.

Take off your existing motor and check the dropout distance first. I have an Ecotric 20" fat tire folding bike. I figured it was your typical 175mm dropout and bought a bigger motor.

After I spoked it up and tried to fit it in, I found my Ecotric model had 165mm dropouts, I couldn't use the wheel,

I would likely go with a (much) higher capacity controller first. Try feeding your existing motor 1500w and see if it makes enough power for you then....

As long as you use your head with your new "turbo mode" the motor will likely survive it fine. Worst case you smoke the motor, and you're where you are at now. Only now, you'll have the controller to support about anything you want to do.

AHicks said:

I would likely go with a (much) higher capacity controller first. Try feeding your existing motor 1500w and see if it makes enough power for you then....

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Bingo. An oversize motor often destroys an undersize controller, sometimes spectacularly. (I remember the one thread where we were excitedly waiting for Mr. Physics to blow up the one controller.) The undersize motor can be the more durable side of the equation when the controller is oversized. Much like too much battery doesn't destroy the controller but too much controller and motor takes out an undersize battery.

Looks like a great price for the bike especially since shipping is included. Don't think you'll get good value for the mods with 36V.

I am not trying to get more power im trying to stop overheat issues. I can overheat the 500w and it completely dies. this is long before even my battery dies. I want to try this exactly and if the controller blows it blows and ill replace it. im very knowledgable with most things.....and this controller will accept other voltages not just 36v theres settings for it. ecotric customer service sucks so far they have told me the dropout is not 190mm im trying to get them to tell me the exact dropout so I dont have to measure it myself.

Even if they told you, you better measure the dropout yourself. It's not that hard to remove the hub motor.

Too, there are darn few manf's that are going to be of much help when it comes to modifying their designs - in ANY way, shape, or form. That's why they even lock down (password protect) controllers. There's nothing in it for them.... and all sorts of downside if your mod goes sideways for any reason. Pretty simple for most to see who you're going to hold responsible because YOUR mod didn't pan out as expected.

If you are overheating a 500w motor, my experience would be there's little chance a nearly identical 750 is going to be any different.

Why are you convinced it's the motor shutting down, and not the controller?

Do what you want though.

devlin016 said:

I am not trying to get more power im trying to stop overheat issues.

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Sorry for misunderstanding your issue. Whenever someone mentions motor upgrade, more power is usually the reason
26" fatbike with 4" wheels is a demanding job for a small-ish hubmotor. Huge wheels makes it difficult for the motor to spin fast enough to be to be efficient. To get the most out of the 20 amps your current controller puts out, you need a "slow" motor that can run efficiently at low rpm. The tradeoff is that your top speed will be low. You can also consider a mid-motor like the bafang bbs02. Since it takes advantage of the bikes gearing it is easy for the motor to stay in the efficient rpm-range at all speeds.

Do you have a temp-sensor in the motor and/or controller? Under what conditions does it overheat? Does it overheat if you use the lower pedal assist modes? How fast can you go with full throttle on level ground? How fast does the motor spin if you lift the rear wheel off the ground while applying full throttle?

devlin016 said:

im trying to get them to tell me the exact dropout so I dont have to measure it myself.

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Just put a ruler between the spokes on top of the motor and eyeball it. As long as your measurement is within +-5mm or so you can look for a motor that will fit.

my controller doesnt seem to be password protected I can change any of the advanced settings. and if that was the case where they make these things were parts cant be replaced I will go complete ape shit... thats so not fair whats a person to do if they burn out there hub motor from over heating........I will contact a lawyer im handicap and this is my only mode of transportation and I feel like thats almost bullying at a certain point it cant be lawful I know that..I own the device i should be able to do whatever I want with it....just like jailbreaking a frocking phone man...we own the devices. the bike has had overheating issues from day 1 i have diagnosed it crazily.... if I used only power mode 4 and lower not 5 doesnt overheat. if I use pedal assist doesnt over heat. if I wait until the sun is not beating down I can ride in 5th power mode and it doesnt over heat..... it overheats if I go out on a sunny day and ride in its 5th power mode without pedal assist. theres not a actual temp reading but i do suspect a temp sensor because I swear this thing is being thermaly throttled before it completly dies. instead of going at its max 22mph in 5th gear it will start to go like 16 or 17 mph then lower and lower then completly dies. I dont think its the controller over heating because the hub motor is wicked hott to the touch where it will burn me so that cant be good and while its dead from overheating if sprinkle some cold water on the hub she comes back to life instantly. and I dont think that 750 is anywhere near the same as the 500w..... that 750w can handle up to 1200w without overheating if you read about it...my 500w sucks it obviously cant be pushed any harder.... and im not a heavy person my body type is slim. can I measure the dropouts without removing the tire from my bike??? mid drive is not an option for me.... on level ground on 5th power mode it will go 22mph if i lift the tire it reports 27 mph.

Geared motors are more likely to overheat than Direct Drive (DD). You might be better off procuring an inexpensive DD kit. Also, seems as though many vendors locate a Chinese company that has a bike they can market, have a certain number manufactured with their name and sell them. They don't know much about the technology.

I am aware of the problems with geared motors. id still like to stay with geared I think.... im defiantly a power use if anyone wondered my skill level.

The obvious solution is to just stay away from mode 5 unless you are going as fast as mode 4 will take you. At high speed the motor is more efficient and does not create as much heat so it might not overheat. The motor you linked looks like it is about the same physical size as your current one, so it will probably not be able to shed much more heat. It is however a little bit slower so it might survive mode 5. At least it will last longer before overheating, but it will only give you about 18mph top speed. It will however give you a little bit more torque.

To go 20mph+ on a fatbike with 26" wheels and 4" tires on 36v/20a is difficult and compromises must be made somewhere.

A direct drive motor like the 9continents is an option, but will give very little torque at slow speeds unless fed with more than 36v/20a.

If it were my bike I would live with mode 4 until I could afford a 52v 50amp capable battery with corresponding controller and a midsize direct drive motor.

No i cant have a mode 5 and not be able to use it... thats stupid i should have full functionality. why do you think the 750w is a tad slower just by what watt i can supply? and honestly i am looking at all options.. show me a kit with direct drive higher amp and volt... 26 inch 4 inch wide...budget isnt a huge problem just doesnt need to be ridiculous i like finding values like I thought this bike was. but the problem there is i need the controller to fix in my existing controller box.... im not going to make my bike ugly....sorry......I need utility and design not just utility.

If a 500w motor is 'wicked hot' to touch then 750 isn't going to be much better as some one already said. Step up to the biggest geared hub you can find which ottomh is something like the mac. ~1000w cont. Probly. Others on the market.
If your hubby is so hot that it is burning you it is already toasted, maybe demagnetised your magnets already. Don't get the new one that hot ever! Temp sensor to go with the display would be really beneficial esp running a geared hubby as the internals are usually too hot by the time the outside feels hot.

it sounds to me like you're asking questions and you don't like the answers from people that have been there, done that.

Time for some hard earned lessons I think.

Also, FYI, the "rule of thumb" is if you can't hold your finger on the hub for 10 seconds without getting burned, the motor is too hot. Probably especially bad for geared motors which dissipate heat poorly. Your system, if it's still operable might benefit from Ferrofluid (ebikesca).

devlin016 said:

No i cant have a mode 5 and not be able to use it... thats stupid i should have full functionality.

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OK, would you complain about not being able to take off in a car from standstill in 5th gear? You should be able to use 5th gear at any speed, right?
Most instruction manuals for manufactured ebikes I have seen specifically tell you to not use the higher modes at slow speeds. They tell you to start in mode 1 or 2 and step up as your speed increases.

devlin016 said:

why do you think the 750w is a tad slower just by what watt i can supply?

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By looking at the rpms at 36v specified in the ad you linked.....

devlin016 said:

show me a kit with direct drive higher amp and volt... 26 inch 4 inch wide

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https://www.ebikes.ca/shop/ready-to-roll-kits/direct-drive-rtr/dd45-ready-to-roll-kit.html
This is just an example for a complete kit that can reliably give you 22mph+ even at 36 volts. Higher volts will give even more.
It will probably not fit your bike. Until you measure your dropouts it is impossible to find what specific kit you can use.
The big motors will still overheat if you go full throttle at slow speed for too long, but due to their ability to store and shed heat this rarely happens as long as you dont climb mountains or pull heavy cargo. To make it idiotproof you can set up temp-based powerlimiting. The cycle Analyst display works great for this.

im not trying to offend anyone im great full for anyones opinion. Im just some what of a perfectionist and im a IT so i know things can be perfect if you go the extra 50 miles.....thats me.. this thing will be exactly what I need it to be even if it takes time......can I measure my drop outs without removing my rear tire? and I dont start off in 5th gear I start off in 1st even know I dont remember reading any of that starting gear in my manual. I just know thats how most of any 'toys' works. and everytime it overheats i do wonder if im causing major damage to it.... it still seems to keep its max speed of 22 but its hott for sure....even when i ride the 4th gear its crazy hott but doesnt cut out.... I cant do Ferrofluid as those fixes dont seem to be legit and look hackerd to me. someone needs to develop a hub motor with forced air cooling or something with a vent and a screen or filter or something.. I know it wouldnt be water proof but id choose the cooling over water proofing....just make sure its a good screen or filter to keep dust debry from getting in the fans.

I already told you how to measure dropout width without removing wheel:

maanebedotten said:

devlin016 said:

im trying to get them to tell me the exact dropout so I dont have to measure it myself.

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Just put a ruler between the spokes on top of the motor and eyeball it. As long as your measurement is within +-5mm or so you can look for a motor that will fit.

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If you want a more precise measure you can use a 90 degree angle on the ruler and measure from both sides, but just eyeballing it will probably get you close enough.

I do understand your frustration though. When you buy a consumer product you expect it to work as advertised without having to baby it. The manufacturer probably should have done some more testing and designed in a little more headroom either by limiting amps to 16-18 or going with a slower motor. It is even possible that the designer did all the calculations based on a 26" wheel without considering that 4" tires makes it effectively a 29" wheel.

thankyou so much I forgot you did say that my bad.. ill get right to making the measurements. im sure the eyeball will be good enough. and the controller does have limiter options if i tune it back it does lower speed and not over heat as much but it still overheats... I think maybe main problem is its geared and its the color black the sun just beats on this thing. I noticed while vacationing in florida all the bike shops were only selling direct drive ebikes it looked like dont know for sure but if they do i wonder if thats for a reason it is crazy hot there compared to me im michigan. it was like 101f there when i went and people were riding there ebikes wtf lol. no fat tires though either im guessing too much drag.

and question i was looking at ebikes.ca or whatever and i noticed they will inject that ferrofluid in the motor for you... do they really do it right? i hear you dont need alot and too much is a drag? i wouldnt want a drag from the fluid i would rather want no fluid if it ment a drag.