constant motor burn out ( gng sucks)

[PARADOXICLES]

long story short i have a gng 2x 48v 450w brushed motor mid mount kit....and its been nothing but trouble, motor burnt out, gng replaced it. then both burnt out, couldnt find an affordable replacements ( pretty much cost of whole kit) so i rewound the coils by hand..... they lasted about 500ft before they burnt out, stopped working and started smoking..... i have less then 40 miles on this ebike and ive basically gone through 5 motors

ive had this kit a year now and spent far too much on it, and it dosnt work.... the only options left i see are to either replace the single 900w cotroller with 2x 450w/500w controlers one per motor, and re rewind the motors, ......or just throw it all infront of a train.....

any one got any suggestions? know where i can get some motors that actually work?.... anything? this is killing me....

 

[riba2233]

Just get a brushless motor.

 

[John in CR]

One controller...no wonder they burned up. They'd need to be locked in sinc to run on one controller, and even then there can be issues because in parallel it's nearly impossible to share equally.

Brushed sucks for ebikes anyway. At over 10 million new units a year put on the road in China, only a tiny % are brushed motors for good reasons.

 

[spinningmagnets]

Yeah, you need two controllers for two motors. Whether its brushed or brushless.

 

[PARADOXICLES]

what source for motors do you reccomend?

ive looked all over for replacement motors, both brushed and brushless, no where can i find a resonable deal, every where wants as much or more for the motors then i paid for the whole kit, brushed or bruhless...... and often they are lower powered..... the motors have to be small enough to fit mid mounted so i can keep the ability to change gears..... the whole reason i chose the mid mount kit

 

[spinningmagnets]

GNG has many kits, do you have a link to the one you have?

 

[PARADOXICLES]

this is what i have, but i modded their stupid 1/8 stainless steel mount that bent super easy by adding a custom 3/8 in hardened steel plate.... now everything actually lines up... but motors burnt out..... i wouldnt reccomend this kit even if it was free.... even if they paid you to take it...
http://www.gngebike.com/900wbrushed.htm

 

[spinningmagnets]

I fear that any more money that you pump into this particular Frankenstein will also be lost. However, to answer your question, I have seen similar motors at TNC scooters and also electric scooter parts. I suggest you save your money and buy an entirely different kit that has a better chance of surviving a reasonable amount of time.

http://tncscooters.com/index.php?route=product/category&path=52
http://www.electricscooterparts.com/motors.html

 

[Tench]

The way those motors are chained up in the link they would run in opposite directions, you did have the polarity switched on one of them didn't you? or they would be fighting against each other!

 

[PARADOXICLES]

and what kit(s) would you reccomend? ....preferably mid mount...

at this point the kit i have is little more then a mount, bottom bracket, front gear, and throtle.... so im pretty sure i could simply replace the motor(s) and controller to prettymuch anything 48v..... i dont care if they are the same, just as long as they work, and are about the same power out put, or more, and 48v input ( cuz thats what my battery is)

yeah those sites dont have any motors in 48v that could be used as a mid mount, too big.... but being 1000w at a similar price, are a much better buy... if i had a gear box with a 90 degree turn and sprocket, i could probably make one work .with a new controller too.... i dunno....

 

[PARADOXICLES]

no there is no resistence, the motors are hooked end to end, and one is reversed, they also have ratcheting sprockets so there is no resistance if spun backwards that way your peddles dont spin like crazy when the.motors are active

 

[dumbass]

Not to pop anyone's bubble but I have run 2 brushed motors with 2 individual controllers and with a single controller. Personally, I didn't see a big difference in the results. But when I ran a single controller it was 48v 50a and the motors were 24v rated so I ran them in series. When I ram this setup with 2 controllers I used 2 - 24v, 35acontrollers. Important to note that each motor had it's own freewheel. One motor always pulled harder then the other because it ran about 20 degrees hotter then the other. But it was still nothing to get excited about.

In the end I found that just running one 24v motor on the 48v controller did a lot better. Of course I had to watch the motor temp. and lighten up on the throttle now and then when the motor got what I considered "to hot" (150 degrees). I ran this setup for about 400 or 500 miles and still running like the day I set it up. But I recently mounted a Bafang mid-drive on another bike and it is so smooth and quite I think the other bike will grow moss on it.

Bob

 

[PARADOXICLES]

bob, i looked up bafang, looks like better quality, what is your top speed on that, and max range? also where did you buyt it?..... i dont really have that kind of money to spend on another kit, but i am looking into all options.

 

[gogo]

What sort of loads were you putting on the motors? (How fast, weight of bike+rider, hills grade & length). You can avoid over stressing the motor by monitoring with a BBQ temperature probe.

Any motor, brushed or brushless, will overheat if continuously run at full power (half no-load speed). The correct technique for continuous duty is to select a gear that allows the motor to operate at a speed that's 75-80% of its no-load speed.

The big advantage of mid-drive setups is their versatility in accommodating hills and wind, both head and tail. This also makes it easy to over stress them.

Also, in multiple motor setups often one motor is doing more work than the other & if you are feeding that motor with up to twice the amps that its rated for its going to overheat and then the other motor will be receiving up to twice the amps it should. Get two temperature sensors @$15 ea. and pick a gear that lets them spin to 75-80% of no-load. I'd guess your expectations about how much power you can safely get out these motors is unrealistic.

 

[PARADOXICLES]

gogo ... i weigh about 130pounds.... the bike itself is about 35, the motor kit was about 22, the battery is about the same, total is 200 pounds or so, maybe 220..... i was in 4th gear on flat ground this most recent test ride that lasted 500ft. ... didnt even make it to the corner

the first burn out was due to manufacturing error, a magnet came loos and jammed the motor, which was why gng replaced it........this is when i put most my miles on it, had no problems in gears 1to 5.

. the second time was as you said, too stressfull, that time i tested its max speed and was in 6th and 7th on mostly flat ground (some very small hills).....

this 3rd time i went super easy on it, started by peddeling, then used motors, kept it in 4th gear, on flat ground ....... it wasnt a matter of too much demand, as there wasnt any streess on it..... anything less then 4th and you go super slow, like 10 mph or less. gng advertised it at the time as capable of 35mph( never expected to reach that speed, but the closesest was 22,mph down hill). though when in first gear it had enough tourqe to wheely very easily

really at this point im thinking the controller needs to be replace, maybe with 2 seperate, or i need to find some higher quality motors.... but i simply cant find any affordable options, the cheepest solution i can find is 2 controlers for 30$ on ebay and another roll of coil wire also 30$, 60 total.... but this option is also a gamble, i do not know if that will solve things, or just waste money i could of invested into a new kit

 

[dumbass]

bob, i looked up bafang, looks like better quality, what is your top speed on that, and max range? also where did you buyt it?..... i dont really have that kind of money to spend on another kit, but i am looking into all options.

The twin setup were twin Currie EZip motors and I had temp gauges on them so I could monitor their heat.

I actually have 2 Bafang mid-drives (750w and 500w .. same motor bigger controller). I'm very happy with the 500w with an 18a controller. I purchased it from http://california-ebike.com/product/8fun-mid-drive-electric-bicycle-kit/ (a US supplier) but it was expensive at $780 delivered. If your willing to order from China I would recommend EM3EV.com

My range is quite good but I'm generally riding on the slow side (15mph and below) on forest preserve trails. Using the PAS I'm using 2ah for 14 miles rides. I use a 48v, 20ah lifepo4 pack so I guess if my butt could hold up my range is over 100 miles. But lets be real!! Max speed I've gotten on that drive is 26mph. But of course at that speed the range is significantly reduced. The great thing about this drive is it hardly feels warm to the touch.

Bob

 

[PARADOXICLES]

bob, wow... 100 mile on 20 ah? .....i have a lipo4 48v 15ah from ping, and before i brunt the motors out, i was getting 18 mpc... at variable speeds, usually 18 mph or so..... why do you like the 500 more then the 750 ? .... and yeah i dont have 700$+ ...and i dont mind from chine as long as its not a clone....want the real.thing........ but if your getting that range, then maybe its worth the money....i dunno.... i wanted to get a second battery and sadle bag it for more range and lower center of gravity, with 30a total, over 100 miles should be easy


how much do you weigh, and the bike? this kit is interesting me alot if your results are true