Bafang G310 geared hub - 11:1 reduction ratio!!!

Not all plastics are the same, so what the containers of a particular liquid are made of may well be safe with that liquid, but that doesnt' mean that any other plastic would be. ;)

As an example, HDPE (commonly used for containers for assorted liquids) is very resistant to a number of things that styrenes are not. There are many other kinds of plastics, and some of them will be resistant to things others are not, and some may overlap in resistance or lack thereof.
 
neptronix said:
Well.... I'd pay you $25 to test transformer oil and report back.

Some reading:
https://en.wikipedia.org/wiki/Transformer_oil

Transformer oil can be stored in plastic containers so i imagine that it is not a threat to the gears or wiring sheaths.
Some transformers contain plastics and wood inside.

So i would guess you are on to something.
Click to expand...

Back to where we started.

We'll see.

Today I opened it up for 10k NTC thermistor attached to windings with JB weld. If I can believe the motor and trip simulators I won't be running the motor much over 65C with cooling. About 20-25C cooler than without according to the models. Cooling is definitely worth doing if true. I can set the roll back at 80C and cut-off at 90C for motor longevity... providing oil doesn't eat it!
I also drilled a disk bolt hole, crammed a piece of 3mm copper tube in with the wire bundle and sealed the bundle. The copper is for a breather. Connect it to silicone hose and maybe a 100ml PE bottle with a pin hole breather or maybe a small filter cut from filter foam with a hole punch and secured with a cable tie and out of harms way. I'll work that out as I go.

I was in the car this afternoon and saw a speed limit sign laying on the side of the road... Score! That'll become the battery base and mounting plate for the baserunner controller.

Life is good! lol
 
Don't you love it when you can harvest wild eBike parts.. :lol:

You know, motor cooling is particularly interesting for any dual reduction hub. The truth is that they can make significantly more power per LB than a single stage reduction geared hub. They are just as limited, if not more, in how they transfer heat to the case. So cracking the oil cooling code would be huge.

I have seen in multiple dyno sheets that the maximum rated wattage for dual reduction hubs is very close to peak efficiency. The amount of rated heat dissipation is then 25w-50w. If we can double that heat dissipation, then my guess is that there's 25% more continuous power on the table.

The Bafang G310 likely uses 0.35mm laminations. Shengyi and keyde both claim peak efficiency that's 2-5% higher. This may indicate the use of 0.27mm-0.2mm laminations. These motors would create less heat the further you push them.

I look forward to seeing the cooling feedback on the new thread.
 
A question from a novice...

I have a basic MTB that I've converted with a CA3 and Grinfineon 20a. I recently swapped the Bafang G020.500 out, replacing it with a G310. I'm VERY pleased with the motor. I gives me plenty of power for the type of riding I do, and it's so quiet.

I don't think I'll have a heat issue, since I don't ride that hard/fast. I'm usually using under 400 watts, but do hit 1000 watts occasionally on starts and short hills. But I'd like to protect it as much as possible. After reading this LONG thread, I'd like to add some oil to the motor if it would help. So I have a few questions...

1. Is 50ml the right amount?
2. Is there a special oil I should use? Grin's Statorade? Something like 3in1? Any silicone oil?
3. Can I just remove the right cover and pour the oil into the case?

Thanx much.
 
Almost all the parts have trickled in so i am about to embark on my g310 build. Looking forward to it

In an odd twist of fate, i picked up a cheap chinese carbon hardtail 26er to put a mid drive on that did'nt fit. I had this sitting around new in a 29" rim i got in here, beautiful wheel build but too big so i decided so get a set of stans Arches in 27.5 to lace up and run 27.5x47's with a rigid carbon fork, carbon bars, stem, seatpost etc and 13s2p 21700 pack in a seat bag

Goal is under 30lbs
 
Someone trusts the structural integrity of cheap chinese carbon frames, forks, and bars, because if one goes cheap carbon frame, one goes cheap carbon fork and cheap carbon bars.

Manbeer said:
Almost all the parts have trickled in so i am about to embark on my g310 build. Looking forward to it

In an odd twist of fate, i picked up a cheap chinese carbon hardtail 26er to put a mid drive on that did'nt fit. I had this sitting around new in a 29" rim i got in here, beautiful wheel build but too big so i decided so get a set of stans Arches in 27.5 to lace up and run 27.5x47's with a rigid carbon fork, carbon bars, stem, seatpost etc and 13s2p 21700 pack in a seat bag

Goal is under 30lbs
Click to expand...
 
Weird as it sounds, I've actually been impressed with a decent amount of the stuff that I've gotten from there recently if I'm very selective not to buy the cheapest shit and only things with lots of reviews. There of been parts and tools I've been waiting on literally over a year but I've been out of stock in America. Some of the stuff I've gotten is actually been as good or better quality then a lot of namebrand things I've purchased. Granted, some has been complete garbage

anyway my wife's going to be riding it and she's 110 pounds and 50% of my work is as a bike mechanic so it'll be checked over rigorously. I don't see the frame catastrophically failing, Fork I'm a little bit skeptical on so it will bear watching. One thing I just can't bring myself to trust are Chinese carbon rims



markz said:
Someone trusts the structural integrity of cheap chinese carbon frames, forks, and bars, because if one goes cheap carbon frame, one goes cheap carbon fork and cheap carbon bars.

Manbeer said:
Almost all the parts have trickled in so i am about to embark on my g310 build. Looking forward to it

In an odd twist of fate, i picked up a cheap chinese carbon hardtail 26er to put a mid drive on that did'nt fit. I had this sitting around new in a 29" rim i got in here, beautiful wheel build but too big so i decided so get a set of stans Arches in 27.5 to lace up and run 27.5x47's with a rigid carbon fork, carbon bars, stem, seatpost etc and 13s2p 21700 pack in a seat bag

Goal is under 30lbs
Click to expand...
Click to expand...
 
adcockj said:
A question from a novice...

I have a basic MTB that I've converted with a CA3 and Grinfineon 20a. I recently swapped the Bafang G020.500 out, replacing it with a G310. I'm VERY pleased with the motor. I gives me plenty of power for the type of riding I do, and it's so quiet.

I don't think I'll have a heat issue, since I don't ride that hard/fast. I'm usually using under 400 watts, but do hit 1000 watts occasionally on starts and short hills. But I'd like to protect it as much as possible. After reading this LONG thread, I'd like to add some oil to the motor if it would help. So I have a few questions...

1. Is 50ml the right amount?
2. Is there a special oil I should use? Grin's Statorade? Something like 3in1? Any silicone oil?
3. Can I just remove the right cover and pour the oil into the case?

Thanx much.
Click to expand...

80ml is just below the axle... 50-80ml is about right.

It isn't a DD... There are gears and unsealed bearings inside these motors to lubricate. There are concerns with oils like ATF which meets the requirements of low viscosity and good lubrication properties eating electricals. My solution was epoxy encapsulation.
If you are going to be putting 1000W into yours it won't last long enough to worry about. Just use ATF.

You could do it that way. Messy and inconvenient. The first time you remove the side cover CAREFULLY drill through one of the disk bolt holes without damaging the threads.
 
Thanx for the info. Kinda sounds like it might be more trouble than it's worth in my case. I've put about 550 miles on it in the past few weeks, so it shouldn't take too long to find out if I'm going to have a problem. I haven't had any issues yet, and anytime I stop to feel the motor, it's barely warm to the touch. We'll see how it works out. Cheers.
 
Definitely do it... The oil part. Don't worry about the encapsulation.
 
TDB said:
Definitely do it... The oil part. Don't worry about the encapsulation.
Click to expand...
If you’re so smart, how come yer not rich?
Seriously entertaining to read one of us imagines they’re smarter than Justin Elmore. Why reinvent the wheel. (Statoraide)
 
tomjasz said:
TDB said:
Definitely do it... The oil part. Don't worry about the encapsulation.
Click to expand...
If you’re so smart, how come yer not rich?
Seriously entertaining to read one of us imagines they’re smarter than Justin Elmore. Why reinvent the wheel. (Statoraide)
Click to expand...

Except that statorade wont do anything in an inrunner like this...? I dont know who Justin Elmore is, but if it is Justin from Grin, he uses oil (I think it was ATF) in his experiments with these motors as well.
 
HrKlev said:
Except that statorade wont do anything in an inrunner like this...? I dont know who Justin Elmore is, but if it is Justin from Grin, he uses oil (I think it was ATF) in his experiments with these motors as well.
Click to expand...

This ^^^^
 
OK. So I understand that adding ~50ml oil to my G310 to lubricate/remove heat is good, but using Statorade is not right for a geared motor (according to Grin). Also, it appears that ATF wouldn't be good long-term for the electrical side. Could someone recommend a specific oil I could/should use? For example, would 3-IN-ONE All-Temperature Silicone Drip Oil be a good choice? Or something else?
 
tomjasz said:
TDB said:
Definitely do it... The oil part. Don't worry about the encapsulation.
Click to expand...
If you’re so smart, how come yer not rich?
Seriously entertaining to read one of us imagines they’re smarter than Justin Elmore. Why reinvent the wheel. (Statoraide)
Click to expand...

Justin doesn't know everything, even though he's damn good at testing and BS sorting.

But i'll say that i've never successfully seen anyone putting oil or ATF into a geared motor and having it last long term. The reason is that ATF and various types of oil are incompatible with certain materials inside hubs.

Someone looking to oil cool a motor might want to follow my suggestion and try opticool's dielectric fluids. AFAIK they are rated to work with every kind of material that would be in a geared hub motor. Nobody has taken up giving this stuff a try.

https://endless-sphere.com/forums/viewtopic.php?t=109746
 
Just curious, has anyone experienced that ATF has done any harm, and what type if ATF? Im only 8-9 months into the experiment myself, so I dont have the answer yet, but so far I have yet to see any ill effects. I didnt do any other research than "take whatever was on the shelf because I want to do it now", (like Justin did) but I would think that a modern ATF fluid would be OK when you see all the electronics inside a modern transmission?
 
ATF seems to have issues with common wiring sheathing and some other electrical components, from what i remember hearing. No direct experience or pictures shown.

Some Opticool formulations are designed specifically to be used in transformers which have materials like wood (yeah, wood!), nylon, other fancy plastics, and other things used in electronics. In fact you can fill a computer up with the stuff and expect it to run perpetually without issues in most cases.
 
neptronix said:
ATF seems to have issues with common wiring sheathing and some other electrical components, from what i remember hearing. No direct experience or pictures shown.

Some Opticool formulations are designed specifically to be used in transformers which have materials like wood (yeah, wood!), nylon, other fancy plastics, and other things used in electronics. In fact you can fill a computer up with the stuff and expect it to run perpetually without issues in most cases.
Click to expand...

I can see Opticool in a DD motor. But are they suitable lubricants for gears and bearings? This is a G310/311 thread and we shouldn't lose sight of all the requirements of this motor.

I abandoned my earlier ideas of finding compatible fluids. There is insufficient information too many variables and too much testing to be done. I moved forward by attempting to make the motor more compatible with common lubricants using encapsulation.

The product... Electrolube ER2225. And ATF. Early days. I am only 7000km and about two months into this experiment.
 
I'd like to see your long term results with encapsulation. That's a very interesting idea. We'll find out how successful you are at the year mark.. it seems to be time, not miles, that destroy components which are vulnerable to ATF.

Yes, how good of a lubricant is opticool? we don't know. They don't list specifications for that. It's probably on the thin side of things.. although you can buy opticool in different weights.. so there may be room for adjustment of lubricity, with the downside of adding fluid drag as you add more lubricity..

OR.. maybe bathing the gears in that oil actually improves efficiency. Have you ever seen how thin a coating a geared motor has after lots of miles, and most of the lithium grease has been flung off to the sides? Perhaps we're being pessimistic!

I think if you could boost your continuous power by at least 25% with a fluid that lead to the gears wearing 2x as fast, it's a modification worth doing. I would expect the continuous power increase to be better than that since heat transfer in dual geared motors is hilariously poor.

I don't like the lower efficiency of geared hubs, otherwise i'd be doing the experiment myself. I've clued Justin into opticool and maybe he'll take up the torch one day.
 
Heat and volatilisation of oil additives is probably as much a factor as time in the breakdown of components.

Documented fretting of bearings was my number one reason for dropping mineral oil as a lubricant and coolant.
While silicone oil is probably a good coolant I am not convinced it is a suitable lubricant at any viscosity for the 13 or so bearings inside these motors. I'll need proof. More than anecdotal or guesses.

I caught this after epoxy treatment of my motor:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=63933
file.php


https://www.sprayon.com/product/el601-red-insulating-varnish/

Sprayon EL601 phenolic epoxy, About 8 bucks per can at Grainger. This class of epoxy has very good resistance to fuels, oils and chemicals and this particular product is made for windings. I've only used these epoxies in fuel tanks (with good results) and if I had known earlier about their use on windings...

Shipping restrictions apply and I can't find them here. If anyone wants to buy a few cans I'd be happy to take the rest.

"Jacks Chariot" ready to ride with 200W maximum (legal limit here for this class of motorised bicycle) to the road. I don't need or want more. I do need it to run reliably and cool uphill. 120W is enough to offset weight and drag most of the time. I do my part.

IMG_0107.jpg
 
neptronix said:
OR.. maybe bathing the gears in that oil actually improves efficiency. Have you ever seen how thin a coating a geared motor has after lots of miles, and most of the lithium grease has been flung off to the sides? Perhaps we're being pessimistic!
Click to expand...

When I filled the Aikema motor with ATF I noticed the consumption with full throttle and wheel in the air went down from 1.1A to 0.9A, so at least the no-load efficiency is a lot better. I had to turn down the electric freewheel current by the same amount.

BTW, does anyone know where to get new gears for the g370? I think all the juddering I experienced while trying to tune it is what have damaged them, but I was slightly disappointed when it started making the typical gear-sounds. I've ordered another Aikema 75sx to replace it, but I would like to experiment a bit more with the Bafang. Sucks that gears seems to be unavailable, unlike the Aikema motors.
 
HrKlev said:
BTW, does anyone know where to get new gears for the g370? I think all the juddering I experienced while trying to tune it is what have damaged them, but I was slightly disappointed when it started making the typical gear-sounds. I've ordered another Aikema 75sx to replace it, but I would like to experiment a bit more with the Bafang. Sucks that gears seems to be unavailable, unlike the Aikema motors.
Click to expand...

Could it use the same gears as G310/311? Those seem to be the same 18-33 gears for both motors and available at least on Aliexpress.
 
HrKlev said:
When I filled the Aikema motor with ATF I noticed the consumption with full throttle and wheel in the air went down from 1.1A to 0.9A, so at least the no-load efficiency is a lot better. I had to turn down the electric freewheel current by the same amount.
Click to expand...

That's quite impressive!

TDB said:
Documented fretting of bearings was my number one reason for dropping mineral oil as a lubricant and coolant.
While silicone oil is probably a good coolant I am not convinced it is a suitable lubricant at any viscosity for the 13 or so bearings inside these motors. I'll need proof. More than anecdotal or guesses.
Click to expand...

I agree that mineral oil is a bad idea. The materials compatibility of silicone oil is also unknown to me. That's why i suggested opticool, which is based on isoparaffin, and the company has published lots of papers and data on materials compatiibility that looks VERY GOOD.

Yet nobody has tried it, despite it potentially being better than ferrofluid.
 
neptronix said:
I agree that mineral oil is a bad idea. The materials compatibility of silicone oil is also unknown to me. That's why i suggested opticool, which is based on isoparaffin, and the company has published lots of papers and data on materials compatiibility that looks VERY GOOD.

Yet nobody has tried it, despite it potentially being better than ferrofluid.
Click to expand...

Mineral oil in this sense is paraffin... Did any of those papers include bearing lubrication?
 
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