MXUS coming out with a 5K-Turbo motor, 55mm Magnets

teslanv said:
It finally arrived! 8)

Here are the test results:

Bare Motor weight: 14.82 Kg (32.6 lbs.)
Winding Tested: 3T
Kv: 13.3 RPM per volt (666 RPM at 49.9 V)
Kt: 0.718 Newton-Meters/Amp (0.53 Ft-Lbs/Amp) [Derived from Kv, not tested directly]
Motor Km: 3.462
No Load Watts: 125 Watts
No Load Current: 2.51 Amps
Phase to Phase resistance: 0.043 Ohms

Thanks for the data.
Well, lets do a comparison of this beast with another beast:
The QSV3 4T with it's lower 11,4kV has already only 45mOhms (self measured). The 4T- V3 with similar kV of 13,3 should have around 35mOhm extrapolated.

This tells me the 5k MXUS has higher losses at given torque than 50h QSV3.
the remaining benefit from the wider stator would be the higher maximum achievable torque output (before saturation), but than we anyway talking about losses close to 10kW..

In veiw of the weight, it isn't really a step forward..
 
madin88 said:
Thanks for the data.
Well, lets do a comparison of this beast with another beast:
The QSV3 4T with it's lower 11,4kV has already only 45mOhms (self measured). The 4T- V3 with similar kV of 13,3 should have around 35mOhm extrapolated.

This tells me the 5k MXUS has higher losses at given torque than 50h QSV3.
the remaining benefit from the wider stator would be the higher maximum achievable torque output (before saturation), but than we anyway talking about losses close to 10kW..

In veiw of the weight, it isn't really a step forward..


True. The MXUS 5K has fewer strands in parallel for a given winding, as compared to a QS205 Motor, thus the slightly higher phase resistance. However, you have both the difference of larger rotor diameter AND 10% wider magnets on the MXUS which may negate the copper fill advantage on the QS205. Hard to quantify without dyno tests of both motors.

What's the weight and no load current on a QS205?
 
markz said:
Can you measure the spoke hole diameter and the flange width.
First page :oops: 250mm and 60mm

The Spoke Hole diameter is 4.3mm. The Spoke Circle Diameter is 250mm.

The Flange center to center spacing is 69mm
 
teslanv said:
True. The MXUS 5K has fewer strands in parallel for a given winding, as compared to a QS205 Motor, thus the slightly higher phase resistance. However, you have both the difference of larger rotor diameter AND 10% wider magnets on the MXUS which may negate the copper fill advantage on the QS205. Hard to quantify without dyno tests of both motors.

What's the weight and no load current on a QS205?

The QS weights around 13kg. No load current not measured.

If we compare two motors with the same kV such as this 5k 3T MXUS vs the 3.5T (or 4T-) QSV3, than the phase to phase resistance will tell you which one has lower copper losses at given torque. The QS is better in terms of this, which is important for the continuos power.

The larger and wider rotor means it is able to produce higher peak torque (before the iron saturates).

logicalliy thought, it can be calculated roughly like this:

MXUS: 20,8² x 5,5 = 2379
QSV3: 19,8² x 5,0 = 1960

-> MXUS 5k has 21% more torque reserves
 
I like the look of the 5k but it's no good for me I can not fit it in my drop outs and retain gears so it's too powerful for my needs it turns a normal push bike into a motorbike and everything that supports it needs to be to this higher speed spec so to me its pushing to far it's only a matter of time till someone's kills themselves with a hyped up ebike and it trends heavier law restrictions.

After stripping the 3k turbo the side cap design is terrible any water that ingress past the seal then has a path directly to the rear of the magnet very poor thought out there needs to be a double edge lip to send any flow back out and provide a proper water tight seal, the bearings again have no level of ingress protection from dirt simple things that need adressing before adding more power or in the process of it, by leaving 150mm dropouts behind I believe they have pushed alot of buyers away the 3k needs a revision to 3.5k.
 
Ianhill said:
I like the look of the 5k but it's no good for me I can not fit it in my drop outs and retain gears so it's too powerful for my needs it turns a normal push bike into a motorbike and everything that supports it needs to be to this higher speed spec so to me its pushing to far it's only a matter of time till someone's kills themselves with a hyped up ebike and it trends heavier law restrictions.

Too much power isn't bad :) , but what bothers me are the 15kg of unsprung mass which turns lightweight e-bikes into suicidal machines..

teslanv, do you know the peak ETA or how to calculate it from the measurements?
 
madin88 said:
Too much power isn't bad :) , but what bothers me are the 15kg of unsprung mass which turns lightweight e-bikes into suicidal machines..

Another good point the weight alone tends to push it towards motorbike territory even if it's to be run at lower outputs the ride needs to cope with the extra mass and when it is turned up to 11 then it's got to be landed in a decent bike or your dicing with death in a DIY way.
 
Too much power? When is it really too much power? If you ask me, the answer is always simple one word answer. Never. And no I am not kidding. More power is a good thing. The user is the one that needs to find a way to use it responsible.

As for weight I too would like to see less weight. Would it be possible to shave of a few lbs if machining the flanges and back iron, then use it as a mid drive? The weight is not that critical for mid drive, but outer diameter reducing by machining flanges and backiron would make for and easier mounting.
 
We all know there will be budget builds with a 5k turbo or more running in a frame with cable operated brakes no suspension and a shit load of lipo with out a care for safety when I think the general public would like something more down to earth and better quality.
I can see me machining new side covers for the stock 3k turbo they are shite look super brittle like floyd mayweather hands I'll be afraid to stand up and peddle and that what a bike is for peddling ebikes these days are emotorbikes they rarely peddle becuase they are going to fast to keep up what's the point in that, Its a waste having the pedals mass there and it's damn lazy it defeats the bikes point so ibetter off being an inboard motor at that point.
 
Don't get yourself all worked up now Ian. People got different needs, and different wants. I understand this motor is not for you, and that is fine. You get any motor that suits your needs. But others may very well have different wants then you. They might not need a more powerful motor, but if that is what they are craving who are any of us to judge them?

Some pedal others don't. Even those who never pedal will have a lot of fun using an electric bicycle. Just because it is a bicycle. You can go anywhere but the freeway, even on the sidewalk. You can park for free, don't have the pain of registration, fees and road toll. Heck even no insurance to pay. And many people will do most of their running about with an electric bicycle, drastically reducing the use of an ICE vehicle. It is green, it is cheap and for some it is even powerful. What's not to like?
 
I love the ebike idea for those wanting to get around but I do think there's one or two problems with the mxus 3k that were intentionally placed there lack or ingress protection and the supporting spider on the cassette side of the hub won't take much pedaling abuse there more strength on the disc brake side which shows the riders they expect to have legless whisels
 
madin88 said:
Ianhill said:
I like the look of the 5k but it's no good for me I can not fit it in my drop outs and retain gears so it's too powerful for my needs it turns a normal push bike into a motorbike and everything that supports it needs to be to this higher speed spec so to me its pushing to far it's only a matter of time till someone's kills themselves with a hyped up ebike and it trends heavier law restrictions.

Too much power isn't bad :) , but what bothers me are the 15kg of unsprung mass which turns lightweight e-bikes into suicidal machines..

teslanv, do you know the peak ETA or how to calculate it from the measurements?

This is a solid point. One has to weigh the benefits of having a 33 lb motor that is rated 5k nominal compared to something that may be half that weight or less, that is rated for 3k nominal but with a few mods { like cooling with ferro fluid, air holes, upgrading phase wires, etc} , now has the ability of 5k nominal, in a lighter weight package that has been slightly modified by the user.

I do think that with the advancements in motor/ battery technology , ensuring that ebikes can now easily go 50 + mph , will lead us to more injuries/ fatalities of people who abuse this power/speed that is becoming available , which will lead to new laws being enforced on ebikes , making it mandatory for law enforcement officers to spot ebikes on the road, and hand out tickets for any ebike that is overpowered or setup to do faster then 20 mph, etc .
 
I do think that with the advancements in motor/ battery technology , ensuring that ebikes can now easily go 50 + mph , will lead us to more injuries/ fatalities of people who abuse this power/speed that is becoming available , which will lead to new laws being enforced on ebikes , making it mandatory for law enforcement officers to spot ebikes on the road, and hand out tickets for any ebike that is overpowered or setup to do faster then 20 mph, etc .

I get where you are coming from. Stealth has had the Bomber out for 9 years, and for 7 of those 9 years, it has been capable of 50+ MPH speeds. I haven't heard of on accident where a Bomber owner has died as a result of riding machine that will go over 50MPH. I did come across an article recently where an Ebiker was killed, it wasn't due to speed of the ebike though. Ebiker vs car, car won. As far as laws go, I don't think there will be new laws, I think the existing laws will start being enforced if we start getting noticed by the cops. And don't think there aren't cops out there that can't spot an ebike a mile away right now, I personally know one that can. :lol:
 
Thing is those bombers are darn expensive and built to spec it's not a diy rig that this motor is design to tender to.

Another problem I found with my mxus 3k is the magnet ring has area where there is no adhesive behind so applying a bead of epoxy to the edge is going to leave air voids and the magnets will still corrode and separate with time.
So what I've done is used loctite 270 thread locker it doesn't interact with the base adhesive and is thin enough to fill in all the air voids and when this stuff sets the magnets ain't going anywhere the hub itself Is a stone throw away from being top notch just a few little assembly issues and the cog flange I don't like but don't be put off its still one of the best in its class but be prepared to strip it before use if you want it to last.
 
Rix said:
I do think that with the advancements in motor/ battery technology , ensuring that ebikes can now easily go 50 + mph , will lead us to more injuries/ fatalities of people who abuse this power/speed that is becoming available , which will lead to new laws being enforced on ebikes , making it mandatory for law enforcement officers to spot ebikes on the road, and hand out tickets for any ebike that is overpowered or setup to do faster then 20 mph, etc .

I get where you are coming from. Stealth has had the Bomber out for 9 years, and for 7 of those 9 years, it has been capable of 50+ MPH speeds. I haven't heard of on accident where a Bomber owner has died as a result of riding machine that will go over 50MPH. I did come across an article recently where an Ebiker was killed, it wasn't due to speed of the ebike though. Ebiker vs car, car won. As far as laws go, I don't think there will be new laws, I think the existing laws will start being enforced if we start getting noticed by the cops. And don't think there aren't cops out there that can't spot an ebike a mile away right now, I personally know one that can. :lol:

Well its not just about the availability of 50 + mph ebikes..but about the ability for more people to build such beasts, for less and less money as technology advances and have such power in walmart brand bikes, that were never meant for such a setup. Comparing a stealth bomber that costs $7000 to a walmart bike modified to be a ebike that can also do 50 mph , is not comparing apples to apples.

As far as your claim of " I don't think they will create new laws" , I disagree. This is what corrupt politicians, law enforcement do for a living to increase tax revenues. More and more laws and eventually this will impact the ebike markets. Probably take hold first, in places like California, New Jersey.
 
rumme said:
As far as your claim of " I don't think they will create new laws" , I disagree. This is what corrupt politicians, law enforcement do for a living to increase tax revenues. More and more laws and eventually this will impact the ebike markets. Probably take hold first, in places like California, New Jersey.

there are already laws in a few EU countries (or at least annouced to be there soon) where all kinds of DIY e-bikes will no more be allowed because they are not tamper-proof in terms of power, speed limits etc.
So even if you riding a DIY bike which conforms the laws (like 25kmh max speed etc), it could be illegal than.

Back to the motor:
Instead of the "more power hype", MXUS better should focus on weight, efficiency and quality of manufacturing.

Since bicycles are available, there was always a big focus on the weight, while on those 3kW hub drive motors there are not the slightest improvements made.
As soon as you need moped rims for tolerating the mass, it should be no more called e-bike :)

Due to the fact that QSV3 has lower copper losses together with 2kg less weight, this 5k is a fail.
 
One way to get around it is to buy a genuine ebike then just keep it within power limits but 350w in a dd hub motor is neither hear no there barely makes up for its own weight at that power level.
And this would only be checked at most in city areas I can't see speed traps and police waiting on bike tracks waste of time and money.
 
Ianhill said:
One way to get around it is to buy a genuine ebike then just keep it within power limits but 350w in a dd hub motor is neither hear no there barely makes up for its own weight at that power level.
And this would only be checked at most in city areas I can't see speed traps and police waiting on bike tracks waste of time and money.

cops would not need to setup speed traps, to pull over ebikers or give tickets. if a officer just saw a ebike, that looked to be going at a high rate of speed, that is enough for the officer to pull you over . As far as your claims that officers would not waste time for such things , I disagree. If they will pull you over for not wearing a seatbelt and give you a $70 ticket for it , then why wouldn't they do the same for a ebiker, if there is revenue to be extorted thru a ticket ?
 
They gotta catch you first ;)
Its easy to zig zag and shoot into narrow coves.

Seeeee Yaaaaaa
But yeah, its not good because you gotta live free or die trying.
 
if a officer just saw a ebike, that looked to be going at a high rate of speed, that is enough for the officer to pull you over . As far as your claims that officers would not waste time for such things , I disagree.

Hey Rumme, I am a cop, and I would not waste my time jamming up an Ebiker. Unless he crashed into a kid in a school zone in the middle of a crosswalk, different story. If an ebiker is riding at less than 20MPH, and pedaling or ghost pedaling on public road, they will not get pulled over, end of story. Even if the ebike is capable of of going more than 20MPH, if the bike can be pedaled under human power only, and the cops don't have to have a reason to pull the rider over, the cops won't ever know that a person is running a 9kw build capable of 60MPH. Cops just cant stop someone based on "because its an ebike". There has to be a violation of law no matter how minuscule the violation is, or some kind of suspicion compliance issue based on articulated factual observations that will justify a stop and investigation. We are protected from that in the USA. That's every American's citizens constitutional right from unlawful detention. I know different states have different laws and regulations, but all states still have to comply with US Constitution. Anyway I can tell by your repetitive comments that this issue is concerning issue for you. I hope my response will help you relax.
 
Rix said:
if a officer just saw a ebike, that looked to be going at a high rate of speed, that is enough for the officer to pull you over . As far as your claims that officers would not waste time for such things , I disagree.

Hey Rumme, I am a cop, and I would not waste my time jamming up an Ebiker. Unless he crashed into a kid in a school zone in the middle of a crosswalk, different story. If an ebiker is riding at less than 20MPH, and pedaling or ghost pedaling on public road, they will not get pulled over, end of story. Even if the ebike is capable of of going more than 20MPH, if the bike can be pedaled under human power only, and the cops don't have to have a reason to pull the rider over, the cops won't ever know that a person is running a 9kw build capable of 60MPH. Cops just cant stop someone based on "because its an ebike". There has to be a violation of law no matter how minuscule the violation is, or some kind of suspicion compliance issue based on articulated factual observations that will justify a stop and investigation. We are protected from that in the USA. That's every American's citizens constitutional right from unlawful detention. I know different states have different laws and regulations, but all states still have to comply with US Constitution. Anyway I can tell by your repetitive comments that this issue is concerning issue for you. I hope my response will help you relax.

I have a story for you . Not all cops, are good cops/ law abiding cops. In my area, we had a cop, that set his own new truck on fire, to claim the insurance money. He was eventually caught and fired from his job. Guess what, he was REHIRED at another precinct in our state { at least that was the rumor that all the locals claimed } . This same cop, pulled me over 1 night on my ebike , for no reason at all and he called 2 other officers as backup. This was about 11 P.M. at night. My ebike also had a headlight, 3 tail lights AND I was wearing a hat that also had a bright light strapped to it. He pulled me over, because he was bored and wanted to know why I was out on a bike so late at night.

So please, don't insinuate that no cop would ever pull over a person on a ebike. But my main point is this..EVENTUALLY, states will pass laws with more focus on ebikes and law enforcement will stop being so lenient about ebikers. IF THERE IS REVENUE TO BE COLLECTED, THEN OFFICERS WILL COLLECT IT. The very fact that a person gets a $70 ticket for not wearing a seatbelt { which is a action that does not endanger another person} , helps prove my point.

When my wife and I took our class to carry a firearm, the officer told us that a officer can pull you over, for just about anything, because there are so many laws on the books that make it legitimate to pull you over.

The fact that you are both a officer and a avid ebiker that rides and builds ebikes, may be reason why you are so accepting of ebikers in general, but most officers are not into ebikiing and if/when more strict laws are created and passed , I believe law enforcement will start to crackdown on ebikers . As of now, its still a overlooked area of
powered travel but I see that changing as more ebikers enter this hobby and decide to use their ebikes to drive in traffic , or go faster then 20 mph in situations where
they can be busted for it. Part of this problem is the fact that to many humans in society, do not use common sense, when they are allowed to operate in a system that does not have checks and balances. They abuse / misuse their freedoms which then bring attention to it, which often ends up with politicians creating new laws.
 
Rix said:
if a officer just saw a ebike, that looked to be going at a high rate of speed, that is enough for the officer to pull you over . As far as your claims that officers would not waste time for such things , I disagree.

Cops just cant stop someone based on "because its an ebike". There has to be a violation of law no matter how minuscule the violation is, or some kind of suspicion compliance issue based on articulated factual observations that will justify a stop and investigation. We are protected from that in the USA. That's every American's citizens constitutional right from unlawful detention. I know different states have different laws and regulations, but all states still have to comply with US Constitution. Anyway I can tell by your repetitive comments that this issue is concerning issue for you. I hope my response will help you relax.

Some cops don't care about the constitution, or morals or integrity.

This is not a isolated case.

https://www.forbes.com/sites/instituteforjustice/2014/03/12/cops-use-traffic-stops-to-seize-millions-from-drivers-never-charged-with-a-crime/#3739c698f54b

If officers will steal peoples money , then pulling over a person on a ebike to give them a citation, is not out of the question, especially if new laws are enacted to focus more on ebikers which could create a larger revenue flow for the FOP , in places where ebikes are more popular.

By the way, I am not trying to insinuate that all officers are corrupt but I do feel enough of them are, that it needs to be addressed and solved, way more then our deceptive and failed media exposes.
 
Some cops don't care about the constitution, or morals or integrity.

Tuche as the french would say, there are some shitheads out there, they will always come and go. If you would like, lets continue this discussion through PMs, I think we are getting away from the topic at hand which is the MXUS 5K.

If we compare two motors with the same kV such as this 5k 3T MXUS vs the 3.5T (or 4T-) QSV3, than the phase to phase resistance will tell you which one has lower copper losses at given torque. The QS is better in terms of this, which is important for the continuos power.
The larger and wider rotor means it is able to produce higher peak torque (before the iron saturates).

logicalliy thought, it can be calculated roughly like this:
MXUS: 20,8² x 5,5 = 2379
QSV3: 19,8² x 5,0 = 1960
-> MXUS 5k has 21% more torque reserves
Maddin, I missed this earlier, but when you say "21% more torque reserves" are you referring to increased work load and thrust potential?
 
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