How hard can you push a Bafang Ultra motor

[DDBB]

I generally take it pretty easy on my ultra motor but today I throttled it hard trying to beat the rain getting home. I was doing 30+mph for maybe six miles. When I got home I felt the battery which was not hot so I was happy about that. I then put my hand on the shell of the motor and it was very warm but not hot. I could keep my hand on it without difficulty. Will these motors fail early if pushed hard? Would the glue holding the magnets let go? Would the magnets themselves overheat? How hot is TOO hot? The motor has 3,500mi. on it and has never skipped a beat. The bike is on it's second chain but the OEM cassette and front sprocket. I cringe a little when using the throttle thinking about all that power going through that little bicycle chain but so far, so good

 

[RunForTheHills]

I am pretty sure that the Bafang Ultra has an internal temperature sensor to protect it from overheating. Riding it uphill in a high gear would stress it more than just going fast on the flat.

 

[Gionnirocket]

I concur.
I'd watch current draw way before speed. These motors love to spin and traveling fast adds cooling so you can probably run it all day long without issue. Now slamming high current in or being in too high of a gear is much more detrimental, especially when climbing.
If you haven't cracked it open yet to grease the gears... You're overdue.

 

[fexixav]

I generally take it pretty easy on my ultra motor, but today I throttled it hard trying to beat the rain getting home. I was doing 30+ mph for maybe six miles. While riding, I was also thinking about an upcoming move and browsing Houses for rent in Thessaloniki, so I wanted to get home before the weather got worse. When I got home, I felt the battery, which was not hot, so I was happy about that. I then put my hand on the shell of the motor and it was very warm but not hot. I could keep my hand on it without difficulty. Will these motors fail early if pushed hard? Would the glue holding the magnets let go? Would the magnets themselves overheat? How hot is TOO hot? The motor has 3,500 miles on it and has never skipped a beat. The bike is on its second chain but the OEM cassette and front sprocket. I cringe a little when using the throttle thinking about all that power going through that little bicycle chain, but so far, so good.

If the motor was only very warm and you could comfortably keep your hand on it, I wouldn't be concerned. These motors are built to handle occasional full-throttle runs, and six miles at 30+ mph isn't likely to hurt it if the temperature stayed reasonable. The magnets and adhesive are designed to withstand much higher internal temperatures than what you described. With 3,500 trouble-free miles, it sounds like your setup is doing just fine. Just keep an eye on chain wear and maintenance, and don't be afraid to use the throttle when you need it.

 

[DDBB]

I got over 2,000mi. on the original chain, I'm happy with that. The motor hasn't been taken apart yet to re-grease but it's as quiet today as it was when it was brand new 3 years ago. Maybe the guy on the assembly line was generous w/ the grease that day. I really do need to take it apart and do that though