I finally got my new 24 fet nuclear controller hooked up and will need more time to fully give my opinion about this controller. This is supposedly the best and most recommended controller for this bike. It does give a lot more power, great display screen, and controlability to the bike even with using the stock battery, with one major flaw.
The controller is still a "work in progress", meaning it works well, but is still in development. It definitely is not a plug and play controller like the x-controller is. You have to really do a lot of reading/research and program it for your bike. You can upload other peoples controller settings so that could simplify things, but nobody really does this yet. It also just doesn't attach to the bike very easily, you will have to deal with mounting it and dealing with the phase and battery wires. Not that big of a deal but its not plug and play, I had to even zip tie the controller down at two locations.
The only reason I am not liking it is the throttle control. I don't know if any of you guys remembered when I was harping about how great it was switching to a thumb throttle on this bike and how much better control I had over the twist throttle. A thumb throttle gives you very precise control and there lies the problem with this controller for me.
The one thing so far I do not like about it is the throttle control. This is something that could hopefully be fixed in the future as it has to do with programming and a firm ware update could always fix the issues.
One thing you guys take for granted is how well the x-controller is programmed for this bike, it gives you very smooth and predictable control of the sur-ron. The throttle is programmed to give you very good control and the controller is tuned so the power flows smoothly.
My biggest issue is that the throttle on the nuclear controller is controlled by phase amps. Basically, it works by setting a max phase amp value in the controller. Assume you set the nuclear controller to 300 max phase amps as that is about the max you can use with the sur-ron battery. You also set the max battery amps, and that is set to 90 as that is about the max you can use on the sur-ron battery.
How the nuclear controller throttle program controls the bike is like this, you push the throttle down say 50% of the way, your controller will allow you to hit 150 phase amps. Push the throttle fully to 100% throttle it will allow 100% or 300 phase amps. So the throttle movement has a direct linear relationship with phase amps, from 0 to 300 phase amps.
This is where the issues lies and is a problem for me. The Sur-Ron uses maximum phase amps only at very low speeds, so when accelerating at 2 MPH you will use 300 phase amps. But when you are cruising above 15 MPH you will only use a max of about 150-100 phase amps.
What is happening is at any speeds above around 15 MPH, only about 25%-30% of my throttle controls the bike, because at 30% my controller is calling for 100 phase amps and that is enough to use my full 90 battery amps. I LOSE about 70% of my throttle range. My throttle is like an ON/OFF switch at cruising speeds. I have a lot of control of my bike because of the very small range of throttle movement to control my speed. So if I'm at full throttle doing 40 MPH, and want to reduce my speed, I have to reduce my throttle from 100% to below 25% just to reduce my speed a little bit. It is almost like my control at speed is ON/OFF.
The bike is still usable but just has awful throttle control, and this is because it is programmed this way
. Think of it like driving a car and when you are driving you had to control the car with only 25% of the movement of the gas pedal. It leads to a very twitchy driving experience. What makes this actually worse for me is my halls thumb throttle ramps up in voltage from 1 volt to 2.3 volts in a very short distance so I really have only about 15% of my throttle movement to control my bike
The only saving grace for you guys with the Sur-Ron twist throttle is that I found the Sur-Ron twist throttle was so bad in giving control of the bike that many of you guys may just go full throttle and then release the throttle fully anyway and may not be too bothered by this issue.
Its a very good controller but the lack of throttle control really kills it for me. I will have to do more experimenting with it and give more feeding on this controller.