New geared hub motor trend: go big!

Has anyone followed the latest trend of chinese GEARED hub motors ? It seems bigger and heavier is the new motto. Here 2 examples:

- The Bafang H640 5.5 KG! Seriously.



- Hengtai/hentach: 5.9Kg! Hengtail also makes that famous nylon/metal gears which are supposed to be stronger.


I guess they are trying to capture the cargo market. Funny thing that 5 years ago nobody was taking high power geared hub seriously even though the cargo revolution was in full motion. An now we finally have something, though at that weight levels, one might consider a DD hub in a small wheel. Also, still no oil cooling!

I always wanted to see a much larger diameter than this one, for cargo bikes, pedicabs, etc. So there would be room for more copper, more magnets, and room for a lower gear ratio. It would have the capability to run 2000w continuous, but not need oil cooling because it would be geared low enough to run with decent efficiency at 3 mph at 600 pounds vehicle and cargo weights.

Flip side of course, would be a very low top speed, possibly sub 20 mph. But towing trailers and such, that's ideal anyway. This one has an rpm of 500 or so, I'd be wanting one geared so low its rpm would be more like 250, without having a low speed wind.

Currently you get this combination with a 20" wheel, and low speed wind. It worked good on my bike, till the cheap battery burned it. But the same performance in a much stronger 26" wheel would be nice.

dogman dan said:

I always wanted to see a much larger diameter than this one, for cargo bikes, pedicabs, etc. So there would be room for more copper, more magnets, and room for a lower gear ratio. It would have the capability to run 2000w continuous, but not need oil cooling because it would be geared low enough to run with decent efficiency at 3 mph at 600 pounds vehicle and cargo weights.

Flip side of course, would be a very low top speed, possibly sub 20 mph. But towing trailers and such, that's ideal anyway. This one has an rpm of 500 or so, I'd be wanting one geared so low its rpm would be more like 250, without having a low speed wind.

Currently you get this combination with a 20" wheel, and low speed wind. It worked good on my bike, till the cheap battery burned it. But the same performance in a much stronger 26" wheel would be nice.

Click to expand...

Well, there is no indication about the reduction implemented into the bafang h640. If they did things right and used a dual style reduction like the g310 with a helical cut first stage, the motor could be a beast. I think we'll have to wait until a least july/august to see the first units. Really curious how they are going to turn out.
The Hengtai is rather classic, albight supersized: single stage planetary reduction using straight cut gears. They claim the metal/nylon gears can take a lot of abuse, but I suspect the drawback is more grinding noise.

I remember a discussion we had 4 years ago, and totally agree with you: there is definitely room for heavy duty geared hubs, since at those power level drive train parts will die in no time. I'm actually quite stunned that most commercial cargo solutions use mid drives; it just doesn't make a lot of sense. Better to separate the low power source (human) from the high power one (motor). Even with my smallish bbs02, at full power I managed to snap a 1/8" bike chain - and that was when trying to haul a heavy trailer uphill...

EDIT: Just realize that huge bafang hub motor is part of the g0 series, not the g3 - so probably classic straight cut planetary reduction too.

Would certainly like to see how these motors stack up to the MAC.... which is still one of my favorite motors.
The weight is off the charts. knowing what the real continuous power level is would be helpful. Where's the dyno graphs, bafang?

If Grin wanted to test one to put it on the simulator, I'd kick in $20 for a buy.

With new motors you can almost always buy, test, and immediately sell for 80% of purchase price.

If I had the equipment, I'd do it just for fun, but...after collecting the data, I'd do a destruction test at the end, to find the limits.

I think a steady-state power level with a stable 140F at the core is the true rating.

there is also Mxus xf19 which is stronger than the mac motor.Many complain it is noisy.Mine is not.And it is cheap

https://mxus.en.alibaba.com/product/1600125689475-810136932/Mxus_XF19_type_1000W_e_bike_motor_geared_electric_bicycle_dc_hub_motor.html

1boris said:

there is also Mxus xf19 which is stronger than the mac motor.Many complain it is noisy.Mine is not.And it is cheap

https://mxus.en.alibaba.com/product/1600125689475-810136932/Mxus_XF19_type_1000W_e_bike_motor_geared_electric_bicycle_dc_hub_motor.html

Click to expand...

On what basis do you say it's stronger than MAC? And do you know what RPM per volt it has?

Stronger than the MAC in which way?
It looks kind of like a MAC knockoff from here. Wouldn't mind seeing a dyno sheet.
Looked at the motor on alibaba.. A 140mm dropout is an odd choice and probably why i didn't look into it further.

I have had 3 mac motors,it feels stronger on hills with the same current.140 mm is not a problem on any of my bikes.The motor is bigger in radius and wider and have bigger gear ratio and are heavier.So it is no suprise really

I posted the dyno sheet somewhere in this forum...

I'm the one complaining about the xf19 noise. Had one here and resold it. Didn't take measurement though. Compared to the mac, it has less torque but can take a bit more abuse, because its gears are wider. I pushed it to 1500w without flinching. Axle cable exit and no l1910 connectors (they use julet z916) are quite a bummer. You cannot replace the nut without cutting the power cable. To be fair, this motor is probably the best bang for the buck by a long shot, if you re building a cargo or a climber. Price including controller is 1/3 of the mac.

I tried to look for some info about hengtai/hentach motors and there's no any. No retail or anything. Seems like covid hit them hard.

szakadimas said:

I tried to look for some info about hengtai/hentach motors and there's no any. No retail or anything. Seems like covid hit them hard.

Click to expand...

Hengtai/Hentach is mainly motor manufacturer. So they have very little retail business. Some of their own motors are also supplied to ebike manufacturers or trading companies, rather than end consumers.

szakadimas said:

I tried to look for some info about hengtai/hentach motors and there's no any. No retail or anything. Seems like covid hit them hard.

Click to expand...

You can actually contact them via their website and get a sample shipped. Did it a few years ago to repair a broken ebike.