Leaf / leafmotor / leafbike high efficiency 1500w motor

I would like a DD at around 4kg that could handle about 1500w with ferrofluid

People are putting crazy power through the 4kg mac, but everyone seems to have problems with the clutch unless they dial the phase amps way down, but then you lose the whole purpose of a geared motor which is the crazy torque
 
tolkaNo said:
I would like a DD at around 4kg that could handle about 1500w with ferrofluid

People are putting crazy power through the 4kg mac, but everyone seems to have problems with the clutch unless they dial the phase amps way down, but then you lose the whole purpose of a geared motor which is the crazy torque
The purpose of any motor is to be used WITHIN SPEC. Is this too hard for you? It's like y'all think engineers are there for decoration.
 
Chalo said:
tolkaNo said:
I would like a DD at around 4kg that could handle about 1500w with ferrofluid

People are putting crazy power through the 4kg mac, but everyone seems to have problems with the clutch unless they dial the phase amps way down, but then you lose the whole purpose of a geared motor which is the crazy torque
The purpose of any motor is to be used WITHIN SPEC. Is this too hard for you? It's like y'all think engineers are there for decoration.

I have my own spec that i wish to use also 8)
 
tolkaNo said:
I would like a DD at around 4kg that could handle about 1500w with ferrofluid

People are putting crazy power through the 4kg mac, but everyone seems to have problems with the clutch unless they dial the phase amps way down, but then you lose the whole purpose of a geared motor which is the crazy torque

The grin tech all axle hub would suit your needs, or a converted bionx d-series (i would have one for sale, PM me if you are interested).
But both cannot make the the torque a MAC can do, or at least by far not that efficient..

Regarding the clutch, i remember a german guy built his own one for a badass 2WD MAC fat bike, but unfortunately it seems to be not offered for sale anymore.
here is his website: https://www.e-bike-technologies.de/index.php/de/
 
I have a 26 inch sun ryhno lite with a few small cracks in the rim. As the hub motor was already giving me some issues Id figure I would just get a new motor soon. How are the rims they build any better than ebay kits or should I just have my bike shop build a will again ? In the wheels defense it was in 3 or so crashes (don't try to pop wheelies at full speed when drunk.) and I rode a week with 2 broken spokes waiting for new spokes to come in the mail.
 
boytitan said:
I have a 26 inch sun ryhno lite with a few small cracks in the rim. As the hub motor was already giving me some issues Id figure I would just get a new motor soon. How are the rims they build any better than ebay kits or should I just have my bike shop build a will again ?

For best results, you want to use 14/15ga spokes and the heftiest rim that works for your frame, brake, tire, and budget. Rhyno Lite is a nice sturdy rim by pedal bike standards, but it's marginal (and thin walled) for e-bike use. Alex DM24 is a stronger and heavier rim of similar size that can be gotten for cheap at Luna Cycle.

Make sure to lace all the spokes outside the hub flanges (or all outside on one side and all inside on the other side to compensate for a dished hub). Lacing inside the flange as many hub kit sellers do diminishes the lateral bracing angle which is already in critically short supply.
 
If you're going to build a 1500w+ motor wheel, i'd consider 14 gauge butted sapim spokes ( which flange out to 13 gauge diameter for extra strength ) to be a bare minimum. May be inadequate for 2kw+ or large wheels like 29ers. A lot of people have had issues running standard bike spokes on powerful hub wheels. Hub motors are usually designed for 12 gauge spokes, as evidenced by the slot holes on 'em.

Your local bike shop won't know what to do with a 13 or 12 gauge spoke because they won't have the tools to thread them unless they're a very specialized shop that builds tandem wheels and such..

The build quality on the wheel i received was very good for a cheap wheel. asked for a 24mm internal rim and got one. Needed minimal truing. But that was back in 2014. No idea about the quality of built wheels sent out today, but i'd imagine they're acceptable.
 
neptronix said:
If you're going to build a 1500w+ motor wheel, i'd consider 14 gauge butted sapim spokes ( which flange out to 13 gauge diameter for extra strength ) to be a bare minimum. May be inadequate for 2kw+ or large wheels like 29ers. A lot of people have had issues running standard bike spokes on powerful hub wheels.

The problem with spokes on hub motors isn't raw strength-- regular bike spokes are about 4X stronger in yield than they need to be. Because hub motors are so large in diameter, fluctuations in tension due to torque are less than with pedal-only bikes.

But hub motor spokes are unusually short-- which exaggerates any shortcomings they have in staying tight under load-- and they enter the rim holes at queer angles compared to traditional bicycle wheels. Both these problems are reduced to one degree or another by using smaller diameter spokes.

When 14ga or smaller spokes are used in hubs that are drilled for 12ga or thicker spokes, it's important to use washers to help the spoke heads fit correctly in the holes.

The strength of the wheel is in the rim, not the spokes. The spokes' role is supportive, and they can do their job more effectively under higher loads when they are thin.
 
neptronix said:
If you're going to build a 1500w+ motor wheel, i'd consider 14 gauge butted sapim spokes ( which flange out to 13 gauge diameter for extra strength ) to be a bare minimum. May be inadequate for 2kw+ or large wheels like 29ers. A lot of people have had issues running standard bike spokes on powerful hub wheels. Hub motors are usually designed for 12 gauge spokes, as evidenced by the slot holes on 'em.

Your local bike shop won't know what to do with a 13 or 12 gauge spoke because they won't have the tools to thread them unless they're a very specialized shop that builds tandem wheels and such..

The build quality on the wheel i received was very good for a cheap wheel. asked for a 24mm internal rim and got one. Needed minimal truing. But that was back in 2014. No idea about the quality of built wheels sent out today, but i'd imagine they're acceptable.

Already used sapim strong spokes. Spoke breaking is what probably caused the issues but wheel was abused the Rhyno lit did really good for the abuse it took.
 
Chalo said:
Make sure to lace all the spokes outside the hub flanges

Would that also be recommended for wider-flanged hubs (like the MXUS 450x) in smaller rims (20" bicycle / 16" motorcycle)? I ask because it would force teh spoke to have to bend around the flange significantly. I'm not sure how much of a stress load it would place on the spoke head and elbow, but I was afraid it would be a problem. (it might also force bending at the nipple exit)

Presently mine are laced on the inside, because of that...but I ahven't had any problems I'm aware of despite significant side-loading, even on my bashed-up rigthside wheel taht's on the narrower Crystalyte HSR3548 (which at thsi piont has at least two sections of rim bead smashed flat, right next to each other from unavoidable pothole edges in traffic).
 
amberwolf said:
Chalo said:
Make sure to lace all the spokes outside the hub flanges

Would that also be recommended for wider-flanged hubs (like the MXUS 450x) in smaller rims (20" bicycle / 16" motorcycle)?

No-- for smaller diameter wheels there is enough bracing angle when they're laced alternating in/out or even all on the inside. I believe that the reason Chinese hub motors all have flanges spaced too narrowly is to make them compatible with rims that are only a little larger in diameter than the hubs.

It's not a problem for spokes to bend around the edge of the hub flange, but it is a problem if they insert to the rim at an angle with respect to the nipples. That predisposes them to break at the root of the thread.
 
Chalo,

The problem with smaller spokes is the interface between the hub and the spokes.
I've built 2 500-750w geared motors with standard 14 gauge spokes, and even that power level had them pinging and loosening from the get go.

There are two problems with this..

1) a majority of hubs are drilled with a certain spoke diameter in mind - 12 gauge. 13 gauge is just barely close enough for low power builds..
2) a majority of hubs also have a divot that's large enough for the head end ( or whatever it's called ) of a 12 gauge spoke. This is meant to give a lot of metal to metal contact also, since a hub motor produces far more torque than a human being and all.

You can use washers to help a spoke too small for the design of the hub-spoke interface be more solid, but it's a hack you want to avoid if possible. You are much better off following the intended design. In my experience, the intended design is pretty good.

I think that the spoke to rim interface is equally important... yes, extreme bends are bad news.. but that's secondary to selecting the right spoke..
 
Chalo said:
The purpose of any motor is to be used WITHIN SPEC. Is this too hard for you? It's like y'all think engineers are there for decoration.

This would be a valid statement if China had unilaterally decided to rate their motors through some method other than 'do a dyno in whatever wheel size and voltage you feel like and make your best guess'.

The leafmotor is a fine example of a motor being underrated the dyno guess method. I showed that this motor was capable of 1900w continuous in a 26" wheel, or 2000w continuous with my simple cooling hack..

The MXUS 3kW is a fine example of overrating because the dyno was done with a 20" wheel to exaggerate it's capabilities. In a 26" wheel, it is more like a 2250w continuous motor despite it's extra width due to the sloppier windings and possibly lower quality materials.

If you followed motor ratings religiously in this case, you'd either be wasting a motor's power potential or overheating it.
I can prove it. I've built a bike with both motors and confirmed the suspicions i had based on dyno data..

Please obtain some experience with high power builds and optimizing for thermal limits vs. power density before you run around here making definitive statements like that.
 
neptronix said:
Chalo said:
The purpose of any motor is to be used WITHIN SPEC. Is this too hard for you? It's like y'all think engineers are there for decoration.

This would be a valid statement if China had unilaterally decided to rate their motors through some method other than 'do a dyno in whatever wheel size and voltage you feel like and make your best guess'.

I think you might overestimate the standardization of such things outside China. It's always going to be a matter of judgment by somebody. The point is that somebody who knows more than you do about the thing they designed and built has offered a power rating that they believe to be valid.

Just because some engineering is done poorly, conservatively, or almost not at all doesn't mean there isn't a rating for each motor. Nobody who designs or manufactures a motor wants to rate it much lower than what they reasonably believe it's capable of producing reliably. When you exceed that rating, it you're on your own-- same as if you put an aftermarket ECU and nitrous oxide on a crackerbox car. It might work, and it might break. But in either case it's a dumb thing to do unless pushing it to the breaking point is what you want.
 
Chalo said:
I think you might overestimate the standardization of such things outside China. It's always going to be a matter of judgment by somebody. The point is that somebody who knows more than you do about the thing they designed and built has offered a power rating that they believe to be valid.

Just because some engineering is done poorly, conservatively, or almost not at all doesn't mean there isn't a rating for each motor. Nobody who designs or manufactures a motor wants to rate it much lower than what they reasonably believe it's capable of producing reliably.

Ah, we are not talking about 'outside China' here though. A quick glance at all the ebike builds here will show that ~98% of the parts added to every bike are China built, China rated, and most often China designed.

My statement even applies to large Chinese companies with a dearth of experience. Bafang rates the G310 as either a 250-500W motor. Once we start looking at dyno data and ebikes.ca's tests, we see that the motor is closer to 700W continuous.

Oldschool 9C motors from when you joined the forum were rated at either 750w or 500w, yet we've seen people sustain over 1000w continuous in a small wheel and produce many multiples of the stated maximum torque reliably for years without overheating or damaging the motor.

Most Chinese companies are overrating batteries and under-rating motors. Almost every company who sells DIY components is doing this for various reasons... underrating motors to feign legal compliance... overrating batteries to get more of them out the door... and sometimes it is just a matter of lack of attention to detail and a reseller passing along very questionable data from an inexperienced manufacturer..

Yes, there is a rating. But you'll have to read between the lines or do the tests yourself to find out.. preferably both, as has been done here.

Please get yourself some more experience building electric vehicles before chipping in on matters like this. You've been here for 10 years and should, at a minimum, know more than me about the reality of how all the components are rated VS what the reality is.
 
neptronix said:
Please get yourself some more experience building electric vehicles before chipping in on matters like this. You've been here for 10 years and should, at a minimum, know more than me about the reality of how all the components are rated VS what the reality is.

I've been building EVs since before that, and it's one of the things I do for a living now. What I haven't been doing all that time is pushing parts beyond their ratings and cooking them. It works for me.
 
I haven't cooked a single motor. Anyone who followed my lead with this motor hasn't cooked it either.
We all know the supplied rating is incorrect.

Pedego made the mistake of trusting their battery supplier's specifications and the recall on their exploding batteries cost them a million dollars. I still have one of their recall packs. The insulation around the pack is burned, yet per assessment of the real world C rate, the pack gives 95% of it's capacity despite being operated as a small space heater for a year.

If you just followed manufacturer supplied data on Chinese components, then you haven't been properly specifying parts. Coincidentally, neither did the largest ebike company in the United States..

Please do the forum a favor and do not advocate taking Chinese supplier's specifications at their word. Learn a bit about how to derive data from an incomplete set of specifications. Even i can do it, and i flunked high school level mathematics. I know from talking to you that you are at least as intelligent as me.
 
neptronix said:
The problem with smaller spokes is the interface between the hub and the spokes.
I've built 2 500-750w geared motors with standard 14 gauge spokes, and even that power level had them pinging and loosening from the get go.
Strange...what kind of rims were used?

I haven't seen these kinds of problems on wheels I've built (or rebuilt) with geared or DD hubs, in anything from 20" to 26" rims (cheap or good) (and my bikes are heavy enough, especially with me and cargo on them, to cause problems on bad wheels *without* adding motor power to the mix).

On my MXUS 450x motors, because the holes were so huge that even 12g spokes rattle around in there, I drilled new holes between the existing ones, sized for the 13-14g butted spokes I used from Grin, to the 20" (16"MC) rims.

If spokes ping and loosen, then commonly either they weren't stress-relieved when built, or the rim is deforming as it rotates, and allowing the nipples to turn. The latter usually happens when the spokes were insufficiently tensioned to start with, but can also happen if the nipple holes have cracks in them (often from too *high* a tension for the rim strength, especially with an average or below average rim quality). It's the sort of thing I see with 12g spokes on OEM hubmotor wheels. (I think I have seen it on every one of the ones I've had so far, with at least one spoke, and the same thing on wheels I rebuilt with 12g spokes).


1) a majority of hubs are drilled with a certain spoke diameter in mind - 12 gauge. <snip>
2) a majority of hubs also have a divot that's large enough for the head end ( or whatever it's called ) of a 12 gauge spoke. This is meant to give a lot of metal to metal contact also, since a hub motor produces far more torque than a human being and all.
While both of those are true, the smaller diameter spokes will still hold tension better, and make a better wheel, when using common average-to-below-average quality bicycle rims (like those used on OEM hubmotor wheels), because the tension required doesn't damage the rims.

If you're using a good enough rim, it doesn't matter if you use thick spokes, if it's designed for the tensions required. Many rims are not good enough, however.

Myself, I wouldn't let the hubs' holes dictate how to build the wheel, unless using rims that are designed for the higher spoke tensions required on the larger spokes. I'd rather use washers like I would on even a regular bicycle hub that had similar issues (some do).

Washers dont' work in all situations. But they can work in most. i've been using them for years on the HSR3548 wheel build that was used on CrazyBike2 and then on SB Cruiser (is still presently on SBC due to axle issues with the other motor that should be there). Bent the rim up on potholes, crushing the bead flange in flat in at least two places, but it's still a functional wheel.

1) <snip> 13 gauge is just barely close enough for low power builds..
Unsure of exactly what you mean, but: If you mean that 13g spokes themselves can't handle more than low power...that's definitely not correct (unless we're talking low-power motorcycle class power :lol:). If it were, then I'd have spoke failures all the time on SB Cruiser--but I don't have any spoke failures on it, with 13/14 butted spokes on the rear, where the side-loading and potholes and bumps all create more than significant strain on the wheels, not even counting the motor power.

I break axles...but not spokes.

I suspect I could use 14/15g butted spokes, and still have reliable wheels, which is a test I'll do eventually when I build the 26"-29" rear-wheel version of the trike.



FWIW, I had some cheap BMX's wheels with 44 spokes, 15g, that I used on SB Cruiser's rear wheels for a while (when I had a front hubmotor on it), and broke a number of spokes, because the rims were not made for anything like the loads I was putting on them, and deformed while rolling allowing spokes to loosen, and then break at the elbow. They could also have had damage from their previous life on the BMX, but I expect my overloading of the rims was the primary cause.
 
neptronix said:
The MXUS 3kW is a fine example of overrating because the dyno was done with a 20" wheel to exaggerate it's capabilities. In a 26" wheel, it is more like a 2250w continuous motor despite it's extra width due to the sloppier windings and possibly lower quality materials.
Definitely lower quality materials, at least as far as the axles go. :/
 
FWIW, I tend to agree that many of the Chinese ebike parts (and probably a lot of other stuff) do not have appropriately tested ratings. Some of them seem to have guesstimates based upon whatever the company that they mostly cloned their own design from said theirs was good for (even if *that* company did the same thing for their own product).

We can't know for sure what testing they have actually done or not done, however, because most of them don't publish any of the data, if they even have it, and those that do usually publish very incomplete data, making it difficult to even extrapolate with reasonable accuracy the data needed to apply the technology to the various uses to which it will be put.


However...if there *was* a spec published for something by these companies, I'd be much more inclined to believe that spec was *over*rated, rather than underrated, and for reliability's sake not recommend pushing beyond it, but not even to reach it, for the average person. I'd only advocate pushing it for those with experience or the willingness to deal with whatever issues it might cause.

In general, we've seen most motors handle significantly more momentary power than they were rated for, and sometimes more continous, so on average it's probably safe to advocate doing that even for the average person, or the noobs, But sometimes, as pointed out with the MXUS3k example, they may not be able to even do what's assumed by the "spec" in the name of the product, in the uses the average person might want them for. ;) We've also seen this with a lot of batteries over the years, both as cells and as packs.


neptronix said:
My statement even applies to large Chinese companies with a dearth of experience.
FWIW, "dearth" means the opposite (scarcity) of what I think you intended there (great deal).
 
Guy's isn't all this why this forum/thread exist....to accurately pinpoint the real world capability of these motors.

In my case I have been regularly pushing 6KW peak, 3KW cont. through my leaf for several years now with out issue after adding every cooling mod under the sun short of water cooling.

I recently made another bike using a MXUS 3K pushing 12KW peak using FF and hubsinks also. I see the 'rating' on these motors as a rough guide to what I can push them to with decent cooling. Typically triple rated power peak, double rated power continuous depending on ambient temps and the capacity of the cooling.

Cheers
 
Any accurate discussion of what a motor can run at without including the gearing (wheel diameter for hubbies), total load, and terrain, isn't worth its pixels displayed.
 
I got so fired up this morning about this topic that i put a video up about it :lol: so at least the debate was good for some motivation.

[youtube]JPmA4L7L2G0[/youtube]
 
amberwolf said:
FWIW, "dearth" means the opposite (scarcity) of what I think you intended there (great deal).

:oops:

Agree with you on the other points.
 
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