2016 Electric Motion EM 5.7 Upgrade

[rastamax]

Hi everyone,

Like the title indicates, I am looking to get more power out of my setup and am looking for advice from people with more experience than me.

Details of the setup:

Motor: Golden Motor hpm 5000B/48V/300A peak/100A continuous
Controller: Kelly KEB48601 350 Phase amps/140A continuous
Stock battery: 13s LiPo 24 Ah
Magura throttle

I use the bike for what it's designed for: pure trials. This means that I rarely need full power for more than 10-15 seconds at the most. This is my first Emoto so I can't really compare it to anything else except the gas bikes and their capabilities. To me it's seems underpowered a bit. Throttle response to me seems ok as I can really control it going snail pace but everyone is raving about hall active throttle so maybe it could be better than a Magura/Domino. Seems quite punchy off the line but could be better cause it's far from launching me like a gas bike would. I know I can't match that characteristic because it lacks a flywheel and clutch but maybe I can get closer to it.

So my reasoning is that maybe I'd be better off with a more powerful controller so I can feed more amps to the motor. How far can I push it without damage. I think there is a thermistor in the motor or at least one in the controller but I can't really monitor temperature in real time. I also read somewhere that the new sinewave controllers aren't as punchy as the old square wave Kelly's so I'm looking for advice on that. I've been lurking about on the Nucular controller thread, it seems like that would work for my setup.

Maybe I'd be better off with a new motor altogether although I would like to keep it if possible. The QS 3000w looks like a great candidate but if someone knows a better option (could be more expensive if it's lighter too), please feel free to give suggestions.

Should I switch throttle too or I will loose the ability to really finely control slow speed?

Is the battery possibly getting old? Maybe voltage is sagging under power and that accounts for the lack of punch. Is there any way I can find out?

I am looking forward to your advice.

 

[SlowCo]

I don't know if you use the top speed a lot? If not maybe shorter gearing might help?
The Nucular controller might be a good upgrade indeed.
How hot does your motor get while riding?

 

[rastamax]

It's geared pretty low already, probably like 35 km/h top speed. So far it doesn't seem to get really hot but it's freezing outside so who knows what it'll be in the summer. I'm basically wondering if I can push 500 phase amp in that motor and still be pretty safe not to damage anything. Also Field Weakening could be nice to increase top speed when I move around from 1 spot to the other.

Would a 24F nucular be overkill or would it actually help with performance?

 

[SlowCo]

I suspect a Thermo Nucular 24F would do great. In many cases the Nucular makes a motor run cooler at the same amp input. I would suggest to up the voltage of the battery and system to 20S at least and increasing the Ah capacity for a "stronger" (less sag) pack. That automatically gives you a higher top speed with the same gearing. And then slowly increase the phase amps and other parameters (speed/torque throttle and sensitivity plus field weakening) until the motor starts getting hot (within the design parameters) with your riding style. And keep an eye on it when outside temps get high(er). After that (or simultaneously) add extra cooling to your motor with a fan.

 

[rastamax]

I'm not sure I can up the voltage all that much on my particular motor. At 72V it would be right around 6000RPM which is the rated limit. It would suck to have magnets flying out of it. I can probably do 16s or 18s when I get around to building a new battery but what I'm really after is more torque rather than speed so more amps. I'll put my name down for a Nucular and do some testing like you suggested.
Thanks for the feedback.

 

[Grantmac]

Increasing voltage will allow you to lower gearing without losing top speed. Also changing controllers for higher phase amps and faster response should make a difference.
Additionally I believe that Emotion offered an electronic clutch which allows you to dial the throttle then "engage" it by releasing the "clutch".

 

[Xtr6]

The electric clutch is only start stop switch and doesn't really do the job that a clutch does with a convential trail motor.
I have a GASGAS txt-e where they mounted a electric motor directly to a gearbox with a convential clutch. This gives the effect that trailbikes need. The sudden releave of torque and a explosion of power. This is the only way to do it. I Have build my own trailbike with a Motoenergy and a sevcon gen 4 with 60 Volt and 540 Amps. But it has not the punch that a gearbox with clutch gives you. The EM 5.7 is nice but for real trail riding you need a convential clutch with gearbox. More battery wil be more weight.
This is something that trail riders don't like. You have to keep the weight under 68 kg.

 

[SlowCo]

I'm not a trail rider but it reads like it would be beneficial to have a "flywheel motor" with a clutch on a trail bike. Basically a QS205/50H hub motor with a thicker outer ring (not lathed down in the middle like normally to create the spoke flanges) and a clutch between the (stronger/reinforced) cover and the drive sprocket. That way you could spin up the motor and dump the clutch for the release of all the stored kenetic energy. A high Kv QS205/50H on a 20S+ LiPo pack with a manual clutch mounted as a mid drive motor geared 3:1 or even shorter seems like an ideal drive train for a trail bike.

 

[Xtr6]

Takes to much place and has to much weight. 20 S is to heavy in a 25 amps. battery. With a smaller battery you will not run a competion run. I was thinking of building a Astroflight in a conventonal gearbox and direct drive the crankshaft. On my DH bike I have the Tangentdrive and this has so much torque, problem is that bike parts are not build for that kind of abuse. But its the same as Yamaha did on there latest electric trailmotorbike.
But the idee that you have is not that silly. Would be worth while trying.

 

[mxs]

The electric clutch is only start stop switch and doesn't really do the job that a clutch does with a convential trail motor.
I have a GASGAS txt-e where they mounted a electric motor directly to a gearbox with a convential clutch.

Are you referring to TXE model? Which country have you taken delivery of this bike?

 

[Xtr6]

The Netherlands.

 

[mxs]

I see, thanks.