Upgraded Fat Tire bike, stopped running, something seems Burnt!!

banshee28

Member
So, I upgraded my fat tire bike with all new components: 52V battery, controller, LCD, 750W Bafang rear Hub, throttle, etc. All was working good for a month or more across all terrains, no issues.
Last ride, rode in some heavy beach sand areas and had some low speed areas where I used full throttle at very low speed. I think this may have really been a bad idea, but it seemed to handle this fine on previous rides.

I did look down at the LCD at times and notice 1200-1500 or so watts showing so i know at brief times it was working hard.

Anyways last ride the motor and LCD eventually turned off and would not turn back on. I peddled home and let cool down. Still no power. However nothing seemed hot or burnt at the time. I disconnected the battery to the controller and let sit overnight.

The next day, I try to plug things back in and quickly heard a sizzle and seen the battery terminals turn black while plugged in to the controller!! I also notice while pushing the bike backwards there seems to be a slight more resistance in the motor.

So I would like some help here on the possible issue. Did I overload or burn out the motor, controller, battery, hopefully not ALL of them, LOL

Any suggestions on how to check things out?
 
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indianajo

Well-Known Member
Lugging a geared hub motor a low speed and 1500 watts is a good way to burn a winding. Mac warns against that, and their motors are limited to 500 W. Electric-bikes.com refused to sell me a geared hub motor at 48 v because we have hills in Indiana. ebikeling quit selling the 48 v geared hub motor I bought from him, and now only stocks 36 v geared hub motors. The short hills we have in Indiana are not a problem, but sustained 1000' hills as CA, OR, WA, CO, are definitely a problem with geared hub motors.
No way to detect a burned winding except for a horsepower against load test. I don't even have enough test equipment to detect that. Something like a chassis dynamometer for bicycles (no such thing).
I suggest you sell of the 52 v battery before you replace the motor. If you must ride in heavy sand with fat tires, buy a DD hub motor that cools better, and use ferrifluid. It won't perform like a geared hub motor, but it might last longer. Or a mid drive, where you might get 200 miles per chain with that kind of environment hazard.
 

banshee28

Member
Lugging a geared hub motor a low speed and 1500 watts is a good way to burn a winding. Mac warns against that, and their motors are limited to 500 W. Electric-bikes.com refused to sell me a geared hub motor at 48 v because we have hills in Indiana. ebikeling quit selling the 48 v geared hub motor I bought from him, and now only stocks 36 v geared hub motors. The short hills we have in Indiana are not a problem, but sustained 1000' hills as CA, OR, WA, CO, are definitely a problem with geared hub motors.
No way to detect a burned winding except for a horsepower against load test. I don't even have enough test equipment to detect that. Something like a chassis dynamometer for bicycles (no such thing).
I suggest you sell of the 52 v battery before you replace the motor. If you must ride in heavy sand with fat tires, buy a DD hub motor that cools better, and use ferrifluid. It won't perform like a geared hub motor, but it might last longer. Or a mid drive, where you might get 200 miles per chain with that kind of environment hazard.
So why do you suggest to sell the battery? In the future, I can easily adjust my riding to not ride this way in this terrain, no problem. Ultimately I will get a middrive bike for this type of riding, but would like to fix this for all around riding which this setup would be perfect for.