How long do planetary gears usually last?

[JGcycle]

I have a 2023 Voltbike Bravo, which uses a Bafang hub drive, and I was wondering how long do the planetary gears usually last? For reference I live in an area that has its fair share of hills, but not many really steep hills. Also there're aren't many prolonged climbs--mostly rolling hills. Thanks in advance for your feedback.

 

[harryS]

I have one geared hubmotor bike where I added up the miles in my logs (excel spread sheet) and was surprised that it was over 8000 (easy) miles in 7 years. Wore out the pawls in one freewheel at 3000 miles, replaced the crank BB bearings last summer, second shifter, and am on the third set of pedals (finally put in some good ones).

Of course, a sustained hill climb could heat up the motor and melt the plastic gears in minutes. I'm wise enough not to do that.

 

[PedalUma]

@JGcycle, It is not all that hard to open the cover and pack them with grease. And that can't hurt a thing. It will quiet the motor. The hardest part is removing six 4mm hex cap screws. There are plenty of videos.

 

[indianajo]

Repeated hill climbs on an over-volted Bafang hub motor did not melt the gears. It burned the winding, shorted a turn. 48 v up to 20 amps on a 36 v 350 w motor. I tried it first with .56 ohm series resistors, but it would not climb the hills at my weight with 36 v.
I wore the gears on a ebikeling 2017 geared hub in ~4500 miles. Same route, 60-77 hills. Load ~330 lb on the uphill leg due to the groceries & ag supplies I haul out to my summer camp. It did not drag when I pedaled it unpowered, just the armature would not drag it forwards. So I was able to ride it out to camp and back home 4 days later unpowered. Replacement was a 2019 MAC12t which I still have. ~5000 miles on that.

 

[JGcycle]

When I do come across a steep climb, I use my lowest gear, and provide lots of leg-power assist.

 

[indianajo]

My lowest gear is 0.8 mph 24:32. I prefer to not run my pulse up to 168 bpm climbing 15% grades. I have rollers. I hit the bottom at 25 mph then can usually climb the next hill with about 10 mph at the top.
My average speed on the flat is about 9 mph. I do not use power on the flats except when the headwind is > 12mph. That can pull me down to 4.5 mph without power. 6 hours at 120-144 bpm is too much exercise.