QS 273 motor 2 different versions ...

[Montage.pl]

Hello.

I want to upgrade my overheating 5kW Cromotor v.2 to something more potent like QS 273 but apparently there are 2 versions of the same motor:

Motor nr.1
http://www.cnqsmotor.com/en/article_read/QS%20Motor%20273%20E-bike%20Hub%20Motor%2012000W%2040H%20V3%20with%2019inch%20moped%20wheel%20rim%20100KPH%20for%20Electric%20Bicycle/1222.html

Motor nr.2
http://www.cnqsmotor.com/en/article_read/120KPH%20High%20Speed%20Electric%20bike%20hub%20motor%208000W%20273%2050H%20V3%20Brushless%20in%20wheel%20hub%20motor/264.html

I can see motor nr.1 has 100km/h but 12kW and motor nr.2 has 120km/h but has only 8kW???
Does it mean that motor nr.1 is slower but has more WATS (torque) and motor nr.2 has less WATS but can go faster?

Another difference is 200mm dropout in motor nr.2 but that's a minor problem.

I have Sabvoton 200A (standard 72200) and 300A ANT BMS so obviously it's my 8 year old Cromotor v.2 that is the bottle neck, during the summer it's overheating quickly and wasting much of the juice that Sabvoton is pushing in it.

Bellow are pics of my eBike.

https://www.instagram.com/p/CadQ2SoLX1c/
https://www.instagram.com/p/CclhmsuLORJ/

Which motor will give highest speed even if it means altering frame to gain dropout?
I don't care that much about torque, this bike is mostly for tarmac.

 

[eee291]

The link with the 12kw figure is actually 4KW continuous and the 8Kw link is continuous power.
QS will not sell you a motor quickly, they want to know what you require and then give you a recommendation based on the data you provide.

They provide 3 different windings for most hub motors: "KV: 12.5/15.6/17.9(optional)" so the fastest is 17.9 revolutions per volt, which is about 1288 rpm at 72V.

 

[Montage.pl]

The link with the 12kw figure is actually 4KW continuous and the 8Kw link is continuous power.

So the one with 200mm dropout that has 8kW could do 16kW peak or more?

BTW Is QS 273 motor the most powerful eBike motor available or there is something stronger than that?

 

[harrisonpatm]

The link with the 12kw figure is actually 4KW continuous and the 8Kw link is continuous power.

So the one with 200mm dropout that has 8kW could do 16kW peak or more?

As a general statement, yes. Variables abound, but yeah, for a short time, they can crank out higher wattage.

BTW Is QS 273 motor the most powerful eBike motor available or there is something stronger than that?

If you wanted to, you could strap a 20kw mid drive motor to a kids mountain bike and get the back wheel spinning at 5000 rpm. Id want to see that. "Most powerful" is a relative statement.

 

[Montage.pl]

"Most powerful" is a relative statement.

OK, what I meant was I would like to put my hands on the hub motor that will give me the highest speed.
Is the QS 273 in regards to my quest the best I can get?

 

[Santacruz]

A point to note. A difference between the two motors is, one is designed for bicycles and one is designed for motor bikes.
So motor nr.1 will have the disc brake on the right side and motor nr.2 will have it (and a different PDC) on the left side.
I cannot see if you have a chain from your photo's, but if so, then this is also to note.

I have been using a QS273 (nr.2 type) on my self built stealth bomber style bike for the last 2 years.
Very good motor, hardly ever gets passed warm. Very, very reliable.
But, from experience, I would say these motors give huge amounts of torque and a fair (but not great) speed.
I am running a 4T wind in a 19" rim, with a Sabvoton 96120 @ 92v. (22s pack)

For me, this motor is great for comfortable cruising and fantastic acceleration.
I don't know about motor nr.1 because, as I have said, this is for a motorcycle and would not have been usable in my build.

 

[eee291]

But, from experience, I would say these motors give huge amounts of torque and a fair (but not great) speed.
I am running a 4T wind in a 19" rim, with a Sabvoton 96120 @ 92v. (22s pack)

So what speed are you getting with your setup?
This is why there are different winding turns to choose from, 17.9 KV sounds pretty fast. I calculated 117 kph with a 20" outer diameter tire.
https://www.omnicalculator.com/everyday-life/rpm?c=EUR&v=Engine_RPM:1228!rpm,Drivetrain_Transmission_Ratio:1,Tire_Diameter:20!inch

 

[harrisonpatm]

But, from experience, I would say these motors give huge amounts of torque and a fair (but not great) speed.
I am running a 4T wind in a 19" rim, with a Sabvoton 96120 @ 92v. (22s pack)

So what speed are you getting with your setup?
This is why there are different winding turns to choose from, 17.9 KV sounds pretty fast. I calculated 117 kph with a 20" outer diameter tire.
https://www.omnicalculator.com/everyday-life/rpm?c=EUR&v=Engine_RPM:1228!rpm,Drivetrain_Transmission_Ratio:1,Tire_Diameter:20!inch

I have qs273 8000w hub motor on a 350 pound motorcycle and a 24s lifepo4 battery. I cruise easily at 50-55mph, bursts up to 65mph. Agreed with the above poster: hub motors in general are fantastic torque, not great for high top speeds. If that's your actual goal, consider a mid drive setup and a high gear ratio. If that's not practical for your setup, and you have to go with a hub motor, but you still want top speed, your focus needs to be on higher voltage battery and a controller that can handle said higher voltage. Look at 100-120v nominal. If you can manage the high voltage, the qs273 with the motorcycle setup will do just fine, either as 8000w or 12000w.

 

[Santacruz]

But, from experience, I would say these motors give huge amounts of torque and a fair (but not great) speed.
I am running a 4T wind in a 19" rim, with a Sabvoton 96120 @ 92v. (22s pack)

So what speed are you getting with your setup?
This is why there are different winding turns to choose from, 17.9 KV sounds pretty fast. I calculated 117 kph with a 20" outer diameter tire.
https://www.omnicalculator.com/everyday-life/rpm?c=EUR&v=Engine_RPM:1228!rpm,Drivetrain_Transmission_Ratio:1,Tire_Diameter:20!inch

When I built my bike, all the figures on paper, gave a top speed of about 125kph. With the bike on a stand and spinning it up in the air, it indicated 115kph. In the real world, top speed is around 80kph. That is adding my weight, the bike weight and wind resistance etc. But also from the real world, I have noted that top speed is rarely used and for me, not that important.
My original idea for my build was reliability. So hub motor with few moving parts, much bigger than needed.
It has worked out well as 1000's km later, it still runs like new. (and it is used all year in all weather). Range is very good, but then I also use pedal assist in built up areas and towns, just throttle out in the country.

However, the point of my original post was to just point out that the 2 motors were built differently and it was maybe something you needed to take into consideration. I.E. brakes and chain drive as well as the different drop out sizes.