Favourite high power hub motor?

11spokes

100 mW
Joined
Mar 19, 2014
Messages
43
What's your favourite high power hub motor anyone? Qs205 v3 vs cromotor. Which would be a better motor and which could handle the most power?
The qs273 looks like an awesome motor but bit big and heavy for an ebike.
Are there any other motors in this power range that are better?
I'm looking for a motor for an enduro ebike frame. I have a 20s 10p Samsung 30q pack. I am pretty set on getting an adaptto controller. Just not to sure on a motor yet. I'm hoping to draw around 130a peak out of the battery so around 10kw max. Another problem I have is where I would get a motor laced locally. :D
 
The cromotor is a QS 205 H50 , modified to lighter weight. Both are now the prefered motors for fast, powerful ebikes. I have both, my cromotor has better acceleration off the start, my QS 205 H50 V3 is faster yet sheds the heat better on long rides.

The QS 273 H40 has no equivalent for power, but could be compared to the Crystalite X 54 for the diameter and magnet height. The QS 273 H50 is a motorcycle motor, it doesn't fit any bicycle frame. Those motors are very heavy, too heavy for most who are after pertormance. They are best for fast heavy bikes that have a lot of battery capacity, like those that are made to carry a passenger on long rides, and/or made with motorcycle components. They are also good for extreme abuse, very steep or very long climbing, because weight is an important factor of heat dissipation.
 
So what is it that Cromotor does if it is the same motor? I emailed them about cost and they say $400 for the motor and that it can run at 6000w for 120hrs without over heating.

Sent from my SM-N900T using Tapatalk
 
6000 w is not much for a big motor with 50 mm magnets. It will not overheat if it is riding fast. Make it climb 10% at less than half top speed, and 6000 w will make it hot in 10 minutes. Make it climb 20% slowly with a few stop and start up the hill, then it will overheat pretty soon. Feed it 20 kw up a 25% hill, and you better go fast if you don't want to fry it.
 
QS205 50H is according to my experience one of the most powerfull/resonnable weight hub motor you can put on a ebike.

At the begining of the forum when we were only few dozens, the 5300 serie from C-lyte.. these was THE BEAST!! and the most powerfull in 2007-2008 but also considered "too heavy!" .. then few years later came the 5400 serie from 32mm to now 40mm magnets/stator.. The member Lowracer demonstrated us alot of potential of that motor and i finally ordered one to review here and also added watercooling to it. meanwhile the cromotor was already popular from Russian/croatiaa guys and then became popular here, always making us to accept heavyer motor to get more power... and then the cheaper version made by QSmotor, the QS205 grown in popularity... then today the QS273 with about 50 pounds.... and no existing cro273 version exist yet :twisted: ... I said YET !... who is welling?? 8)

The tendency seem to demonstrate that for people that like high power ebike, the heavy motor are more and more accepted.
Even me, i never tought that the QS273 could also get that interest!! 50 pounds! think about it !! however other people than Luke bought it and it grow in popularity... yes guys the average high power 10kW+ setup ebike might forget about diet and climb from 100 to 120 pounds average... lol

porblem is that with higher power, battery and controller size must follow!.. even the ebike size too..

How can you imagine that higher power on a standard ebike lenght 9wheel base) can be sustained... if that power is in torque then the ebike will be only a wheelie machine... or if the torque remain in a limit to not flip over, then any power increase must be translated to higher speed!.. average higher top speed are now between 100 to 120km/h .. but John and Luke brang that to above 100mph!... what's next? :lol:

Yeah.. as well.. better powerband!!

Doc
 
Yep. I am at 52" wheelbase and find it short, although 52" is the average length of a 30 HP Trial motorcycle. Geometry will have to stretch with higher power. Yet I have some reserve about weight. For my short sport rides especially, 100 lbs is too high and feeling like a handicap already. With EV Power, adding weight at one place is calling for weight at another, and the escalade is soon out of control. Bigger motor is calling for a bigger controller, then bigger battery, then all this weight is calling for motorcycle brakes, and wheels, then suspension... To the point that soon, we'd better buy and upgrade an e-motorcycle, than building our own.

Yet, I do plan my Fat Boy Chopper with 62" wheelbase and well above 100 lbs. This one might have a 50 lbs motor, because it will carry a passenger all the time and speeding a lot of weight long distances does require that kind of power and heat dissipation.
 
MadRhino said:
6000 w is not much for a big motor with 50 mm magnets. It will not overheat if it is riding fast. Make it climb 10% at less than half top speed, and 6000 w will make it hot in 10 minutes. Make it climb 20% slowly with a few stop and start up the hill, then it will overheat pretty soon. Feed it 20 kw up a 25% hill, and you better go fast if you don't want to fry it.

My build is for Florida FLAT roads, there are no hills. So either motor will be fine and this does not really answer the OP's questions. With reading everything in this thread it it seem both are great and one is custom and cost more and the other is stock and cost less.
 
Yep, but it is the H40.
The 273 with 50mm magnets is much wider. The other reason after weight, that is keeping me from buying one right now.

The QS 205 H50 V3 is overkill already for most riders.
 
It's important to keep in mind if you're not proficient on a motorcycle (and maybe even if you are) you will find even the 205 / cromotor extremely intimidating on a decent controller. Not only because they make a boatload of torque from idle but also because bicycle wheelbases are pretty short so it will be less stable against wheelies under acceleration.

In other words if you have no experience with anything that has high power and a twist throttle you'll probably crash the bike straight away or loop out when you first accelerate due to whisky throttle.
 
flat tire said:
It's important to keep in mind if you're not proficient on a motorcycle (and maybe even if you are) you will find even the 205 / cromotor extremely intimidating on a decent controller. Not only because they make a boatload of torque from idle but also because bicycle wheelbases are pretty short so it will be less stable against wheelies under acceleration.

In other words if you have no experience with anything that has high power and a twist throttle you'll probably crash the bike straight away or loop out when you first accelerate due to whisky throttle.

Thanks but be rest assured I was racing dirt bikes at age 11 and have owned rice rockets and of curse most of all a Puch moped :wink:
 
MadRhino said:
Yep, but it is the H40.
The 273 with 50mm magnets is much wider. The other reason after weight, that is keeping me from buying one right now.

The QS 205 H50 V3 is overkill already for most riders.

Ya the weight is like 40bls which I think would screw with the center of gravity a bit to much on such a light build of 120 or less
 
Hey guys thanks for all the helpful info!1

So if a qs 273 h40 would fit a 155mm dropout. How would this compare with the qs 205 powered handling wise and what would be the weight difference. What is the qs 273 h50 dropout size?
Also I have contacted qs about the qs 205 v3 and they recommend an 11.4 kv winding with a 19' moto rim which I believe is around 24' with tyre 84v 120-130 amps with a top speed of 65-70 kms. I would prefer higher torque with reasonable but not to high top speed.
Just wondering what you guys are using kv wise with what setups?
And does an 11.4kv winding sound ok for what I'm after.
Thanks.
Ben.
 
You should check the spec and drawings with QS motors. Also, QS motors does make motors mods to your spec (within a reasonable range of specs)

By memory only:

The QS 273 H50 V3 is 189mm dropout width W/O freewheel (200mm W single freewheel), 21.5 Kg in its lightest version. It is made in various configurations, for scooters, motorcycles, cars, with different weight and width.

The QS 205 h50 V3 is 150mm dropout width W single freewheel (can be mod to 146mm), 12.75Kg

If you want lower top speed and higher torque, use a higher KV in a smaller wheel. Yet the torque of those motors is very high already, and you need to build adapted geometry to be able to hit max torque on a start. Possible peak torque above 300nm.
 
I have (sort of) a build log of my bike with a 273 here, https://endless-sphere.com/forums/viewtopic.php?f=6&t=85338
And the electric enduro frame, while the dropouts are far enough apart, they are about 10mm wide, while the QS273 h40 has ~12mm axle flats. I have the 273 in the 11.46kv wind and it has way more than enough torque for me, and I am sure it would have more with a more "aggressive" controller (which I can't imagine) than my kelly.
 
I have read your build thread. Big battery !
For the weight and range, the choice of a 273 was good. It will last and give you many years of fun.

I don't like the frame personnally, but with such a big battery it had to be that sort of frame anyway. Post a vid when you can, not a FPV, we want to see it going. :wink:
 
Hi I'm new here can new to ebikes Could anyone tell me what is a good controller for my 3000w hub motor will be good for power and speed.

Thanks in advance Rich
 
Just to add a little more info...

If you run a heavy high power motor you will also need better brakes and more weight in the front to get the bike to handle decent. If you don't have a reasonable weight distribution, when you go to turn the front wheel will slide and you will end up having the earth to come up and meet you very quickly :lol: . I speak from experience :wink: .

So everything needs to be considered and balanced...a huge, heavy, high powered motor like a QS273 is great but remember you have to feed the motor so a larger battery, a larger controller, larger brakes, larger tires, stronger wheels, etc. may be required. I am not saying you can't or shouldn't do it...just that it isn't as simple as buying a bigger motor.

You need to start with a good frame and one option I discovered is the "Nyx" frame: http://www.nyxbikes.com/nyx-frames. Turns out, doctorbass who commented above was involved in the development of the frame so there is somebody with some actual high powered ebike experience behind it :D . There are a lot of other good options out there as well.

I'd also recommend paying fairly close attention to the comments by MadRhino...he has built several high powered bikes and is another one with experience.

Both doctorbass and MadRhino as well as a bunch of others have been very helpful to me. BUT I came to the conclusion that "speed" was not my primary objective...especially since dv/dt can get pretty traumatic the faster you go. For those not aware, dv/dt is the change in velocity vs the change in time and it basically means the faster you go the worse you are going to get hurt when you crash AND everybody crashes at some point.

My preference is to build a bike that has high acceleration from 0 to about 28 or 29 MPH. Acceleration is what your body feels and gives you an adrenaline rush...you can't tell the difference between 10 mph and 800 mph, they both feel the same assuming you are in an enclosed space.

My approach is to use the motor that has the highest acceleration per amp. It is a MAC geared hub motor. If you run every motor in the menu on the Grin Tech Motor Simulator, the MAC has the highest acceleration per amp except the 750W Bafang geared hub motor but the Bafang hub motor actually has little bitty phase wires so you can't feed it much amperage in reality...therefore the MAC is the king as far as acceleration per amp and the MAC only weighs 4.3 Kg.

The MAC does have limitations! If you want to go over about 30 mph the MAC is a bad idea...because it is a geared hub motor it does not reject excess heat to the atmosphere very well so if you want to push more than about 20A continuously (which equates to roughly 30 mph on level ground) through it then you need to find a different type of motor like a direct drive hub motor i.e. the QS 205/273, a Cromotor or etc. You can run much higher amperage through the MAC for short periods of time...see below :D.

If you want to feel a lot of acceleration (from 0-28/29 mph) and have a fairly light bike (my steel frame hardtail with a MAC and a 14s6p battery weighs 62 lbs) an 8T or 10T MAC may be the best motor for you :D .

Regardless of what type of motor you think you want, I'd highly recommend you run it through the Grin Tech Motor Simulator and see what the temperature does and compare it to other motors for acceleration and speed.

I have been running my MAC with a 52v battery and the 12 FET controller set to 40A battery and 112A phase current for several years and have never had a problem with the gears or the clutch. I ran both a 10T MAC and a Cromotor through the Motor Simulator and the MAC peak acceleration is 8.02 mph/s and the Cromotor is 6.98 mph/s...once you exceed about 20 mph, the Cromotor has higher acceleration.

The MAC is just another option...just be sure your circumstances do not exceed the MAC's capabilities. I have mine set to start reducing the power if the core reaches 130C and to shut down if the temps get to 140C. I came up with those numbers after Justin told me he ran a MAC at 145C on the dyno without any damage.

Remember...if you want to go faster than about 30 mph then go with a direct drive hub motor and if you want to ride off road then I'd recommend a mid drive like a BBSHD but for "fun per dollar" or fun per pound", it is tough to beat a MAC :D .
 
I've had a Cromotor, some QS205 V3s and a QS273 40h V3 all in the EEB frame but with different combinations of battery packs and controllers over the last 8000 miles or so.
The Cromo and the QS205's (I still have 1 good 205) are really good except that they get really hot when under load. Although the 273 is heavier it runs much cooler (28 miles 2500 ft in climbs barely luke warm) whereas the others would be hot over the same route
Acceleration on all of them is excellent - depending on how and what you feed them with.
 
999zip999 said:
Mac a greared motor really . Versus a Cro ?

Yep, the MAC has more torque per amp.

Want to push high amperage for a long time...the MAC is a bad idea, it can't handle it because it will overheat.

Want high acceleration for a short period of time...the MAC will out accelerate the Cromotor assuming you supply the same amperage.

One of the nice things about the MAC besides the more torque per amp is the weight. I can pick my bike up easily and load in the back of my truck since the total weight is 62 lbs. and it handles really good because the weight distribution is just about 50/50 front/rear.
 
Yea tried of the wieght I heat my bmc600 fs like my edge 1,500 but have more time to heat my muxus 3,000 v3 4t But this is my wieght limit A 205 to heavy.
 
Back
Top