MXUS 3000 Hub Motor - V1 V2 V3

[John in CR]

Teslanv,

You worded the poll as if the myth regarding torque wound motors was true. Kiwifiat and Kingfish got their legs cut out from under them by the real experts, so the myth is toast. Even Madin88 has come around though he prefers to save some weight in copper outside the motor, There's no difference in torque the torque they can make, and different winds make the same heat for the same torque. A high turn count motor doesn't make you able to run a bigger wheel, or climb a mountain any better.

Not true John, the matter is still under intelligent debate in kingfish's tread. It seems that you place an incredible amount of faith in the opinion of Liveforphysics, good for you.

As a scientist I need proof and I haven't seen it yet, but will be happy to be proven wrong. That proof will need to be a bit more rigorous than "liveforphysics said so".

There's no debate in Kingfish's thread. You and he were both on the wrong side from the start, because neither of you considered the change in resistance. We gave you simple examples where the math proves it quite simply and with certainty.

Here's a March 2011 quote from Justin, our forum host and maybe the smartest guy in the world when it comes to ebikes,

If the myth continues that the slower speed motor winding leads to a higher torque motor, then ARRG I will want to roll in a grave.

 

[tomjasz]

As a scientist I need proof and I haven't seen it yet, but will be happy to be proven wrong. That proof will need to be a bit more rigorous than "liveforphysics said so".

Maybe you could compare credentials rather than out snark each other. Just a suggestion.

Regards,

tomjasz, rocket scientist.

:lol:

 

[Miles]

As a scientist I need proof and I haven't seen it yet, but will be happy to be proven wrong. That proof will need to be a bit more rigorous than "liveforphysics said so".

You could read an introductory book on electric motors? This is so basic that it's amazing that we're still needing to "debate" it..... Just for the record, I've no technical qualifications whatsoever

 

[liveforphysics]

If you read through this thread, keeping in mind the first post in it contains a lot of incorrect BS, you too will have your own understanding and hence won't need to listen to confused folks misleading you.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=64907&hilit=math

 

[Stevil_Knevil]

KF's first post also included a quote from John in CR.

Much respect for all of Y'all, but I saw BS dropping from somewhere further South

 

[John in CR]

KF's first post also included a quote from John in CR.

Much respect for all of Y'all, but I saw BS dropping from somewhere further South

If you believe that, then you are a victim of innocent belief in the myth that so called torque wind motors are capable of making more torque. They aren't and that is simple fact.

Here's a quote from Justin back in 2011 on the subject

...If the myth continues that the slower speed motor winding leads to a higher torque motor, then ARRG I will want to roll in a grave...

http://endless-sphere.com/forums/viewtopic.php?f=2&t=24593&start=165#p381600

 

[999zip999]

Is it true a slower wind wouldn't melt as fast on a long hill. Or john what are the plus side of a slow wind. There must be a plus side to a 5t. Can't be all bad.

 

[teslanv]

What I have taken from the "myth" conversations is this:

A higher-turn (Lower Kv) motor like the MXUS 5T has the ability to provide the same torque as the 4T with ~20% less phase amps needed at a given voltage. The only advantage to this that I can see is the ability to run smaller phase wires to the motor. (The stock phase wires from MXUS are 2.5mm2 or ~13 AWG, so not very big.)
The lower Kv motor will also reach peak efficiency at a lower speed (given the same voltage) than the higher Kv motor. - So if you don't want to ride fast all the time, the 5T is perfectly acceptable.

What you DON"T want to do is run the same high Phase Current that you might with a 4T motor as you would with a 5T motor, since you are more likely to toast the windings in the 5T motor.

I think what John in CR is saying is that if you want to Hot-Rod a motor, it's better to choose a lower-turn (Higher Kv) motor, since it can handle more phase amps than a lower Kv motor, or conversely, you can get the same performance with a lower voltage and higher phase current with a high Kv motor as opposed to the low Kv motor.

 

[John in CR]

What I have taken from the "myth" conversations is this:

A higher-turn (Lower Kv) motor like the MXUS 5T has the ability to provide the same torque as the 4T with ~20% less phase amps needed at a given voltage. The only advantage to this that I can see is the ability to run smaller phase wires to the motor. (The stock phase wires from MXUS are 2.5mm2 or ~13 AWG, so not very big.)
The lower Kv motor will also reach peak efficiency at a lower speed (given the same voltage) than the higher Kv motor. - So if you don't want to ride fast all the time, the 5T is perfectly acceptable.

What you DON"T want to do is run the same high Phase Current that you might with a 4T motor as you would with a 5T motor, since you are more likely to toast the windings in the 5T motor.

I think what John in CR is saying is that if you want to Hot-Rod a motor, it's better to choose a lower-turn (Higher Kv) motor, since it can handle more phase amps than a lower Kv motor, or conversely, you can get the same performance with a lower voltage and higher phase current with a high Kv motor as opposed to the low Kv motor.

Exactly, and because we have practical voltage limitations, the speed wind motor is capable of higher power. That's because it can handle more current but both are subject to the same voltage limitation. LFP has stated that controllers are so efficient at making the motor "see" a lower voltage at lower speed that at partial throttle the speed wind motor can duplicate the torque, rpm, and efficiency of the slow wind motor with both motors running the same voltage. I don't fully understand that yet, so I have to go along with that concept despite some reservations related to what happens with phase currents at reduced throttle. In either case, the difference won't be huge, so if you want a fast wind motor to behave like the slow one running the same voltage, simply use a 3 speed switch at a lower setting. That will even give the added benefit of better throttle control on launch.

I would add cheaper controller cost and size as an advantage in favor of the slow wind motor, since lower currents can be supplied with fewer mosfets. In the case of a bigger motor like the MXUS3000, running it conservatively and with low top speeds, then the higher turn count motor can make sense. I don't believe that's why people buy them though. Instead they are victims of the myth and have been sold on the widespread misconception that they make more torque, so they're better at handling hills or can run large wheels better.

 

[markz]

Does this mean I can run a lower voltage and higher amperages with a 4T, which ?perhaps? will give me more noticable torque.
If I am not mistaken, More Voltage = More Speed, More Amperage = More Torque (Also smaller wheel diameter)

 

[Hube-]

I just received my MXUS laced to a 24" wheel. Can anyone recommend any innertube for the P35D powercycle wheel? Do you think moto tubes could fit?

 

[arkmundi]

I just received my MXUS laced to a 24" wheel. Can anyone recommend any innertube for the P35D powercycle wheel? Do you think moto tubes could fit?

Would you mind detailing the lacing pattern and answer zipman's question on dishing? Some of us are lacing our own wheels. Thanks.

 

[John in CR]

Does this mean I can run a lower voltage and higher amperages with a 4T, which ?perhaps? will give me more noticable torque.
If I am not mistaken, More Voltage = More Speed, More Amperage = More Torque (Also smaller wheel diameter)

They're all capable of the same torque, power, rpm, etc. For the 4T and 5T to have identical performance, the 4T just needs lower voltage and higher current. If you're likely to chase performance, then the 4T will give you more flexibility and ultimately the highest power for the least price. That's because we can readily find controllers capable of producing more than enough current to burn any of these motors up, and the faster wind can handle the most current, but we run out of room in terms of voltage.

If you're certain that speed will never be on your wish list, eg say 30mph or so is the maximum you'll ever want, then the case can be made to use a higher turn count motor so you save a some of weight and space in wires and controller.

My standing recommendation regardless of which hubmotor you use is to run the smallest wheel you can live with. Hubmotors are geared too steeply, which is why they have to be so big and heavy, and the only way to reduce the gearing is with a smaller wheel size. It increases torque at the wheel, and since reduced gearing has the same effect as reducing the load load, it gives you better efficiency across the operating range. Wheel size is a totally separate decision from what motor to get.

 

[999zip999]

So what motor is best for my needs. I'm putting on a ebike on bike trails and beach. My bike went 36mph was fast for a hardtail. I now run a 2810 at 30mph and great hill climbing. Works well.It also gets saturated and the amp load goes down, saving battery for longer distance. A 4t would be so fast for the streets of a So Cal beach town. I just don't need to be the talk of the doughnut shop. If they start talking my ebike life is over. I like speed but I would ride W.O.T. and 50mph plus is just to much for an ebike. And an frankenbike is to much for a So.Cal beach town. I once saw an aluminum 427 in a 914 had to start in 3rd. gear. I bit uh a waste.

 

[teslanv]

zip,

You do not need >30mph speeds, and you want high torque with (I assume) minimal phase current.

I think the 5T motor was a good choice for your intended use.

 

[999zip999]

It's this conversation does not take in all the needs of the end user.

 

[John in CR]

It's this conversation does not take in all the needs of the end user.

The 4T can do slow with exactly the same torque, speed, power and efficiency as the 5T. That factors in all users other than those already married to a specific voltage and don't want to try a different way to get to the same desired top speed that's arguably better, ie using a speedier wind at less than proportionately higher voltage, and give up a bit of torque on the first revolution or 2 of the wheel (where torque is commonly too high to manage anyway with slower wind large motors) in exchange for greater acceleration to top speed that is artificially limited by the controller. Heaven forbid someone try something new instead of staying on a path they were directed to originally based on pure myth.

AFAIC instead of debating about 4T or 5T you guys need to be leaning hard on trying to make a 3T become available.

 

[arkmundi]

You do not need >30mph speeds, and you want high torque with (I assume) minimal phase current. I think the 5T motor was a good choice for your intended use.

No, no, no. The ES community should get good at making recommendation for intended use. A 1000-1500 watt MAC, Bafang or eZee is what most people should want for urban, park & beachside riding. Its what I just completed on my Trek Shift 3. I'm loving the ride. I'm doing 25-30 mph now and staying about even with street traffic, which was my goal.

So why a MXUS 3000? Pure speed, in the order of up to 50 mph, which is about as fast as I'd ever want to go on a bicycle. Because you've got a long commute, or are trekking long distances where speed matters. There are some significant downsides to a motor like the MXUS, including the added weight, both for motor and battery to power this beast. And charging times. I'm still thinking through the remainder of components for this build. Waiting for more info from John in CR about controllers. Then the battery - maybe 72V, maybe 96V. I'll not need it until the spring so time to ponder over the winter.

The point being, know motors, batteries, controllers, costs, watts consumed, before making a purchase and then make an informed purchase. The MXUS is really too much motor for the average consumer. But when speed matters, and you know what you're doing, or willing to learn, then go for it. And when in the make, make sure the various components are sufficiently rugged to handle the power, from wheels to shocks to frame.

 

[teslanv]

You do not need >30mph speeds, and you want high torque with (I assume) minimal phase current. I think the 5T motor was a good choice for your intended use.

No, no, no. The ES community should get good at making recommendation for intended use.

That's like saying the US congress should get good at agreeing with each other and start passing laws that everyone will support. :wink:

For every ebike build there are probably half a dozen solutions that will work well.

For 999zip999, that could have also included a Mid Drive Fat Tire Bike.

Actually, this one here might suit you well, zip.

http://endless-sphere.com/forums/viewtopic.php?f=31&t=63964

For the record, my BBS02 Hardtail is my favorite ebike, but perhaps only because it is the bike I have ridden then most.

I'm straying into unknown territory with these MXUS high-powered DD hubs, and enjoy it as well. Experimentation is what leads to new discoveries.

 

[arkmundi]

No, no, no. The ES community should get good at making recommendation for intended use.

That's like saying the US congress should get good at agreeing with each other and start passing laws that everyone will support. :wink:

Well, yea - that's the job and what we voters hire them to do. Statesmanship, discussion, debate, agreement, compromise, lawmaking. Sometimes they do and do good. What we should expect. And about ES - if there is not good information, discussion and recommendation, why would anyone come here? Again, its what we should expect of ourselves.

 

[teslanv]

There is great information on ES, but not everyone agrees on what is the "best" solution to a given scenario.
If anything, I see the biggest problem with custom ebikes is too many choices, and no clear "right" answer.

 

[amberwolf]

Also, there may not be a single best answer, as multiple solutions may all work equally well, and/or be just as cost-effective.

A 1000-1500 watt MAC, Bafang or eZee is what most people should want for urban, park & beachside riding.

Here's a question you may not have considered: what about those that don't want to go fast, but want to *get to* their max speed very quickly?

As an example, on my bikes, I'd really rather be able to easily out-accelerate any car or truck when I'm stuck in front of a line of them at an intersection (red light), so I don't end up with them forgetting I'm there and running me over when they see green and hit the gas pedal. But I don't need to reach a speed higher than 20MPH in the normal course of riding (though I want the ability in case of another situation that comes up periodically, where braking wouldn't prevent a collision but acceleration would).

1500W won't do that, at least on my bikes (even the most normal of them, DayGlo Avenger). On CrazyBike2, 2WD of 2500-3000W barely does it, vs most of teh cars. But the most aggressive of the drivers have cars with very powerful engines and very quick acceleration, and I don't yet know how much power I'd need to have sufficient acceleration to get out of their way. If I only had 1WD the problem is even worse, even with more power in a single wheel (as it seems more of the power is wasted as heat in the single motor than in a pair with power split between them).


I dont know yet how true it is, as I haven't done enough experiments to find out, but it seems that motors capable of higher speeds using a particular battery and controller will also be more capable of reaching a particular much lower speed faster than the same battery and controller would reach that speed using a motor capable of only that speed at it's maximum.

I know all the arguments one way or the other about using a *different* battery or controller with the *same* motor to get different speeds/accelerations, but in some (perhaps many) cases it is easier to change just the motor, because the existing battery and controller may be the only ones taht will fit on the bike, or the investment in them was enough that the rider can't get new ones of those, but could get a new (or used) motor instead, that fits the bike the same as the old one.

So in those cases, that could be where a "high speed" motor like this one could come in handy--especially if it is put into a much smaller wheel than the 26" typically used.

 

[arkmundi]

I don't know, except for myself. But I'm one to do R&D, as I did before making my purchase decisions. And then shared in a meaningful way. And when newbies coming asking, I point them to my Top 10 eBike Conversion Kits & Where to Buy list. I don't aim to inform the elite crowd, just the average schmoo on the street. A starting point at least. Note that in the list I have not included the MXUS 3000 watt motor, nor will. For me, an experiment as yet uncompleted, untested. And certainly not for anyone on their first eBike.

 

[999zip999]

Terrain !!! Needs.
Plus I have fatbike with broken fame, yes motor too. People just give me stuff.

 

[teslanv]

I agree the MXUS 3000W motor is not a "Noobie" Motor.

I like to recommend the 1000W 9C clones and BBS02 mid drives for Noobs.

Then once they are addicted to the eBike grin, it's easy to convince someone they need more power.

A drug dealer would do well in this business, I think. :wink: