Mxus v2 versus Cromotor ???? scam??

Electric Motors and Controllers
Post Reply
Ixlr8   1 mW

1 mW
Posts: 18
Joined: Sep 15 2015 8:59pm

Mxus v2 versus Cromotor ???? scam??

Post by Ixlr8 » Sep 15 2015 9:27pm

HI, ok, I bought from a Chinese company claiming to have a 5000w 50mm stater hub motor that looked and speced out like the cromotor, so I bought it but to my surprise what I received was actually what they called a v2 45mm stator that they claimed was a newer model of the 5000w.(and more powerfull) So comparing this one they sent me it would look like its actually a mxus v2 ( I assume copy of ) rated at 3000w 45mm stator. ( right out of the box I noticed how narrow it was and it used a 7 speed cassette instead of a single sprocket as the cromotor has too)

Now they claim that the 3000w 45mm is actually really a 5000w one but of course with a 45mm stator..............but I also noticed that now in their new ad they stated once that it was indeed a 3000w and then a second latter a 5000w. The deal is I bought and paid for what they had advertised as a true 5000w hub motor with a 50mm stator...........in fact they also have advertised right next to the 50mm one in their site the new improved (so they say)45mm one they actually sent me, and its lower priced by 150.00.
Yet they still insist they did me a upgrade......................sounding like a total scam now!....any thoughts on this, I have only days to file a dispute...thanks

Should of added I'm planning to run at 72v.any fast help ,, please?

User avatar
amberwolf   100 GW

100 GW
Posts: 28925
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Mxus v2 versus Cromotor ???? scam??

Post by amberwolf » Sep 15 2015 9:58pm

If what you bought said it had a 50mm stator, and what you got didn't, then you didn't receive the product you ordered, and you should dispute it on that basis.

For myself, I would never trust a vendor that "upgrades" me to a different (probably lesser) product than what was ordered.

If there were no time limitations, I would insist on them sending me the correct product for the original price, with no additional shipping or other costs to me. (including if they want the wrong product back, they would have to pay for shipping it back).

If there were time limitations, I would insist on a complete refund, including shipping costs. (and if they want their wrong product back they'd need to pay the shipping costs for that, too).


What you do is up to you.



FWIW, I dont' know whether the motor you got is better than what you ordered or not. How motors work is a little on the complicated side (see the Science, Math, and Myth thread and a related one linked there by Miles for the details).

I suspect what you got is not as good (torque-wise, anyway) as what you ordered, but you would have to have both of them side by side to either test them or to do the measurements from the motor threads and calculate what they could do.

But it also depends on your use for the motor, and what you need out of it, as to which will work better for you.

Ixlr8   1 mW

1 mW
Posts: 18
Joined: Sep 15 2015 8:59pm

Re: Mxus v2 versus Cromotor ???? scam??

Post by Ixlr8 » Sep 15 2015 10:49pm

Thanks Amberwolf, I have to agree with you , I'm just being very careful about reporting a person if all they did was make an honest mistake,,,,,,,,,,of course saying I'm getting a 5000w 50mm and then sending me a 3000w 45mm motor would seem to point out dishonestly more then mistake. I'm heavily into rc drones and do understand kv and etc............and this seller trying to convince me that the lower rated motor is actually more powerful just does not add up......he just now did offer a 50.00 refund if I keep the motor he sent, not too fair considering I paid around 150.00 more.

BTW it was advertised as a available in a 10 and 9kv...I chose the 10kv for higher speed...........the one I was sent is rated at 11.5 , way too high for my combination needs, at least I feel.

User avatar
amberwolf   100 GW

100 GW
Posts: 28925
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Mxus v2 versus Cromotor ???? scam??

Post by amberwolf » Sep 16 2015 1:02am

If it was just a mistake, I'd expect them to first attempt to rectify it, rather than to justify it. (even if by just *first* offering you a discount/partial refund, rather than doing that *after* attempting justification)

Attempting to justify it calling it an "upgrade" does not make it look like a mistake, to me.

It is of course possible it is just a mistake that they cannot afford to fully rectify, and so first they try to get you to accept it as-is, so they don't have to lose their money. But this is not an honest way of doing things, even though it is not that uncommon. (BMSBattery does it often).

But what you choose to do about it is up to you.



FWIW, this is one reason why many of us keep telling people to use known-good vendors, rather than going with the cheapest option. You might get a good deal, or you might get screwed. Usually not a lot of recourse in the latter case with the cheapest options. With the known good vendors...they're known as good for a reason. ;) Either they'll fix any problem they created, or there won't be a problem in the first place.

meelis11   100 W

100 W
Posts: 116
Joined: Jul 30 2013 5:29am
Location: Tallinn, Estonia

Re: Mxus v2 versus Cromotor ???? scam??

Post by meelis11 » Sep 16 2015 6:55am

If provided motor can suit your needs then I would ask 150$ refund - and call it as compromise (refer that web listing that is 150 cheaper). That way they see that you are willing to make compromises and probably accept your offer.
If it does not suit your needs, then make dispute (ask full refund plus shipping back money)

Ixlr8   1 mW

1 mW
Posts: 18
Joined: Sep 15 2015 8:59pm

so, is the Mxus v2 as powerful as the cromotor?

Post by Ixlr8 » Sep 16 2015 8:24pm

This is in a way following one of my other questions that has been answered very nicely here, but I'm starting this one as a new thread to avoid confusion....

Simply put is the Mxus v2 3000w hub motor as powerful or near the power of a cromotor 5000w?? do they even compare to each other?....thanks so much!

BTW both being ran at the same 72v

User avatar
amberwolf   100 GW

100 GW
Posts: 28925
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: so, is the Mxus v2 as powerful as the cromotor?

Post by amberwolf » Sep 17 2015 2:12am

Powerful as in watts of heat shedding ability?

Powerful as in max watts of power to the ground vs max watts into it?

Powerful as in torque?

Powerful as in max speed?

There's a thread by Miles for a motor spreadsheet, which may have the comparison info you're after. I don't have a link, but searching Miles' posts for spreadsheet should find it.

Ixlr8   1 mW

1 mW
Posts: 18
Joined: Sep 15 2015 8:59pm

Re: so, is the Mxus v2 as powerful as the cromotor?

Post by Ixlr8 » Sep 17 2015 9:59pm

Hi, actually 3 of the 4.............with this build I'm not really concerned with watts in vs out efficiency, more in the line of just brutal power /torque ..thanks for your reply and suggestion

Ixlr8   1 mW

1 mW
Posts: 18
Joined: Sep 15 2015 8:59pm

Re: Mxus v2 versus Cromotor ???? scam??

Post by Ixlr8 » Sep 17 2015 10:08pm

thanks so much for everyone's very quick replies, due to many issues I'm running against lately I just wanted to double check myself that I was not being too picky and decided I should seek a little advise from the forum...............thanks so much

update, I did contact the seller and believe he now realizes the jig is up and now has changed his tone, its still a shame that some sellers will push you around when all you really want is to have a nice smooth deal

John in CR   100 GW

100 GW
Posts: 14255
Joined: May 20 2008 12:58am
Location: Paradise

Re: so, is the Mxus v2 as powerful as the cromotor?

Post by John in CR » Sep 19 2015 9:47am

Cromotor has 5mm more stator length (50 vs 45), so assuming the magnetic forces are proportional, it has 11% more torque potential. That's not the real story though, because unless you're talking about a very short duration like a drag race, the limits of our motors (especially hubmotors) are thermal, so running at full torque potential means quick and certain failure. If you're comparing them in stock form, the external surface area and internal designs are almost identical, and can therefore dissipate virtually the same heat at any given temperature. That means whether you want to or not, it comes back to efficiency, and I don't know the full details of either to comment on efficiency other than to say it's probably pretty close (they're the same design), and controller setup, load, and gearing (wheel size for hubbies) along with how you ride (our intermittent use of torque can result in huge differences in the heat generated with small changes in throttle use) make far more difference than a 5mm difference in the stack of stator lams.

The best way to compare the 2 motors, since it's unwise to push motors to saturation and assuming you're talking about a typical ebike with a typical load so either has more than enough torque to flip you on your back, is to compare them based on the amount of copper taking Kv into consideration. Unfortunately we still don't have Cromotor in Miles' motor comparison spreadsheet to make that kind of comparison simple.

Next would be build quality. Cromotor is well past the early issues of mistakes that resulted in things like magnets coming unglued and broken axles. MXUS otoh doesn't even have winding the stators down pat to get optimum fill, and it's been on the market for too short a time to be considered a proven AFAIC. Is that worth the extra cost of the Cromotor? I don't know, that's up to you. FWIW, what I care about is price/performance from time proven motors, and I view them both as sub $200 motors FOB China, so I have no interest in either.

User avatar
Allex   1 GW

1 GW
Posts: 3228
Joined: Dec 05 2011 8:46am
Location: Stockholm, Sweden

Re: so, is the Mxus v2 as powerful as the cromotor?

Post by Allex » Sep 22 2015 4:58am

John, perhaps it is time for you to enlighten us on what motors we should be interested in. I am talking about <10kg motors here.

John in CR   100 GW

100 GW
Posts: 14255
Joined: May 20 2008 12:58am
Location: Paradise

Re: so, is the Mxus v2 as powerful as the cromotor?

Post by John in CR » Sep 23 2015 5:00pm

Allex wrote:John, perhaps it is time for you to enlighten us on what motors we should be interested in. I am talking about <10kg motors here.
If 10kg is the cutoff that makes a significant real difference (which is fallacy, because the effects of unsprung weight once properly dampened is heavily dependent on the sprung mass), not just a suspension tuning issue, then 10kg is way too high and people should only be interested in under say 4kg hubbies or getting the motor out of the wheel.

Instead of directing people to specific hubmotors I'd much rather they gain an understanding of their heat generation, along with the simple fact that gearing (wheel size), controller tuning, and matching the motor to the load, have a much greater effect than which motor is used in a given weight range.

Post Reply