21kw+ QS273 won't outrun a 250cc?

[Lebowski]

Yeah, not going mid-drive. One of the main reasons for going electric is simplicity. I don't want to have to worry about chains or belts, etc.

Simple is only simple until you spin an axle by stuffing kNm through a couple cm^2 worth of axle cross-section.

I never understood why hubmotors are not build more like drum brakes...

 

[litespeed]

Agreed! Seems like so easy to do and room for the biggest wires also. Win-win!

Tom

 

[c70r]

The only electric bikes I've seen reach the low 3s in a 0-60 mph are mid drive bikes.
One is a 50kW build but geared for 100 mph and the other is a 30kW build but geared for 50 mph but reaches 60 through flux weakening.

There is a drag racing build here on endless that is also using a QS hubmotor though the 14kW model and is pushing closer to 80kW peak out of it. Though at that price point I think a ME1616 pushing 60kW would have been a better solution.

 

[Sunder]

What controllers are people using to get that kind of power?

 

[markz]

My guess is a Kelly KLS-8080I/IPS – High Power Opto-Isolated Sinusoidal Wave Brushless Motor Controller (72V-144V) (200A-700A) <---remember Kelly uses Phase not Battery amps.

or a Sabvoton or Secvon
Here is Doctor Bass' 50kw gig, using Sevcon
https://endless-sphere.com/forums/viewtopic.php?t=79212

 

[Sunder]

I'm using the biggest 144v Kelly there is, and that's really capped out at around 30kw battery power.

 

[eee291]

You could go with the KHB square wave Controller.
I think they go up to 43Kw@144V or 60Kw@120V

 

[markz]

Yeah there are many different models of Kelly to choose from, sure your aware of that.
Some even have funky box designs that arent norm variant as ebikes usually are. Motorcycle and small car units.

 

[Sunder]

Well, lets get it working first and improve it from there.

Right now, its just lines on a graph, and an expectation that this bike will be underwhelming.

Better to be pleasantly surprised if I am wrong, than frustrated and trying to find a "fault" that doesn't exist if I have just under speced.

 

[ridethelightning]

mobipus 72200, asi bac8000 controllers i suspect will give better results(just from trawling,not personal experience yet)

me i like smaller light bikes with good power/weight ratio over big heavy tanks...going over 100 on highway gets boring fast anyway.

id be maybe ditching the kelly, changing battery config for lower volts, more amps to use better foc controller with flux weakening, getting lightest "moto frame" possible...or use a stealth or raptor type frame..then the 273 will be fun.

 

[Ohbse]

mobipus 72200, asi bac8000 controllers i suspect will give better results(just from trawling,not personal experience yet)

me i like smaller light bikes with good power/weight ratio over big heavy tanks...going over 100 on highway gets boring fast anyway.

id be maybe ditching the kelly, changing battery config for lower volts, more amps to use better foc controller with flux weakening, getting lightest "moto frame" possible...or use a stealth or raptor type frame..then the 273 will be fun.

Agree wholeheartedly on all points, but I think you might have meant the Mobipus 72600 rather than the 72200. For a 273 you're going to want huge phase amps.

Kelly is rubbish, 144v is in no-mans land for controller options/bms/charging etc. 20s is optimum for this kind of requirement. Select a winding option on the hub to land at ~90km/h on 72v nominal, the Mobipus or most other quality controllers (not Kelly) will easily run the motor to 1.5x base speed while delivering big punch <100km/h where you actually spend majority of your time.

0-100km/h in <3 seconds isn't easy - but I think you can get close with a hub bike, though perhaps not at 130kg+

 

[liveforphysics]

mobipus 72200, asi bac8000 controllers i suspect will give better results(just from trawling,not personal experience yet)

me i like smaller light bikes with good power/weight ratio over big heavy tanks...going over 100 on highway gets boring fast anyway.

id be maybe ditching the kelly, changing battery config for lower volts, more amps to use better foc controller with flux weakening, getting lightest "moto frame" possible...or use a stealth or raptor type frame..then the 273 will be fun.

Agree wholeheartedly on all points, but I think you might have meant the Mobipus 72600 rather than the 72200. For a 273 you're going to want huge phase amps.

Kelly is rubbish, 144v is in no-mans land for controller options/bms/charging etc. 20s is optimum for this kind of requirement. Select a winding option on the hub to land at ~90km/h on 72v nominal, the Mobipus or most other quality controllers (not Kelly) will easily run the motor to 1.5x base speed while delivering big punch <100km/h where you actually spend majority of your time.

0-100km/h in <3 seconds isn't easy - but I think you can get close with a hub bike, though perhaps not at 130kg+

Thats all excellent advice.

ASI BAC8000 is another candidate to add.

 

[Sunder]

I think right now, the cost to replace all the bmses, chargers and controllers, and have the wheel rewound is a bit high, when I don't even know what the real world performance is.

The good thing is that once it is registered as a road worthy electric motorcycle, I can make modifications to it within some pretty wide parameters without a need for recertification.

There may get be a Mk.II, but I should focus on getting Mk.I working first.

 

[ridethelightning]

mobipus 72200, asi bac8000 controllers i suspect will give better results(just from trawling,not personal experience yet)

me i like smaller light bikes with good power/weight ratio over big heavy tanks...going over 100 on highway gets boring fast anyway.

id be maybe ditching the kelly, changing battery config for lower volts, more amps to use better foc controller with flux weakening, getting lightest "moto frame" possible...or use a stealth or raptor type frame..then the 273 will be fun.

Agree wholeheartedly on all points, but I think you might have meant the Mobipus 72600 rather than the 72200. For a 273 you're going to want huge phase amps.

Kelly is rubbish, 144v is in no-mans land for controller options/bms/charging etc. 20s is optimum for this kind of requirement. Select a winding option on the hub to land at ~90km/h on 72v nominal, the Mobipus or most other quality controllers (not Kelly) will easily run the motor to 1.5x base speed while delivering big punch <100km/h where you actually spend majority of your time.

0-100km/h in <3 seconds isn't easy - but I think you can get close with a hub bike, though perhaps not at 130kg+

yeah, thats mobipus 72600, sorry, typo.