RadMini 4 Controller upgrade review

[Altema]

RadMini 4 upgrade: Having more fun, but enjoying it a bit less



While that may sound contradictory, it was the best way to sum up the results of the RadMini controller and display upgrade I recently performed.
The upgrade was all that they said and more, delivering much more power and torque than I expected. It was definitely fun, but was not without a few caveats.
The installation itself was plug and play for the cables, and the only issue was the cable from the controller to the display. It was was a bit short, and I had to route that cable across the front of the controller to reach. I was concerned about the bike being scratched by the controller box, so I placed adhesive rubber pads on the controller to prevent that, and secured it with three heavy duty cable ties. The cables attached fairly neatly to the stock tie down points.







The display would normally be easy, but it was more complicated on my particular bike because of an aftermarket handlebar extension bar I use for my headlight. The original display mounting points are snug against the stem, while the new ones are slightly wider, occupying the only usable space for my handlebar extension. What I had to do is cut the extension bar mounts and screw them to the new display mounts using longer screws.









The software setup was fairly easy, though you need to watch a video to learn how to access the settings for your particular bike. I wrote out the instructions and the settings for the RadMini 4, if anyone is interested. It should be noted that the top speed remains about 20 mph, even when changed in the settings. I tried minor and major changes, and even when set to 40 or 70 kph, it topped out at the same speed and you can feel the motor back off.

Usage
For controls you get the same three button control pad, with a few differences in operation. The middle button is power on/off with a long press, or cycling thorough display screens with a short press, showing different data such as max or average speed, trip odometer, battery voltage, etc. Up and down buttons change the power assist levels with a short press (also same as stock). A long press on the up button turns on the lights, and this is much easier than holding the middle and up buttons, which is difficult when wearing gloves. A long press on the down button activates... cruise control!

For cruise control, you need to be going a steady speed above 5 mph (7 kph), either by pedaling or using the throttle. Then you need to hold the down button for what seems like a very long three seconds, then a "C" will appear where the PAS level usually displays. At that point, you just let go and steer, and the bike maintains that speed. I set mine to 11 mph, and  it held that speed even going up a steep hill, only dropping to 10.8 mph for a moment. The cruise control cancels if you use the brakes or throttle, or if you pedal and the power assist kicks in. It does not have the ability to resume the set speed like a car, but I'm not complaining!

Riding experience
So, how is riding now? To be honest, I was a bit stunned. The motor now peaks around 1200 watts, and you NEED both hands holding on. It pulls hard and rushes to top speed, and you may even leave normal car traffic behind for a bit at intersections. I blipped the throttle when coming into the house, and it did a burnout on the kitchen floor. Hills are cake now, and I encountered a grassy hillside that was shaped into three tiers because it was so steep. The Rad just drove right up, and the front wheel kept coming off the ground. If anything, the upgrade dispels the myth that the Rad motor is not a 750 watt motor. Over one thousands watts and making the bike fishtail as it spins the back wheel and flings dirt behind it. Plan on taking off when the light changes by pedaling and using the throttle? Better know how to handle a wheelie! It's fun, but be careful not to scare any pedestrians.

It is quite a power boost from the stock Rad riding experience, but is it all good? If I was going to hang out with other e-bikers and compare specs or drag race, the upgraded controller is the way to go. However for everyday living, and depending on your riding style or preferences, it might be a different story.
I think if I was going to look at the biggest difference between a stock Rad and the upgraded version, I'd point to the philosophy behind the power delivery and programming. As delivered, a stock RadMini 4 is easygoing, approachable, and it delivers power in a smooth, and predictable manner. This philosophy extends to the way you get that measured assist at every PAS level up to the top speed, and after you pass that top speed, the power gently rolls back in when you get back below the speed limit. The motor control has a flow to it that encourages pedaling, and you enjoy the ride and don't think about the technical aspects of it all, aside from knowing the throttle is always there to give you a boost no matter what.

With the upgraded controller, you are hit with the impressive power, but it seems like it was made for those who prefer a moped style experience. The power application is abrupt for both PAS and throttle, and the only way around it is a deep dive into the settings. You can't use the throttle one handed because it will pull hard enough to lose control. You can't have a passenger on the back and use PAS 5, because they will likely be launched off the back! Granted, if you have a passenger who is annoying, this could be considered a feature

Speaking of annoying, another odd quirk is the individual pedal assist speed limits. Set the power assist to level 1, take off, and at 9 mph the motor turns off, leaving you with no pedal assist or throttle. It's as if Gandalf is sitting on your handle bars, looking at the the speedometer trying to get to 10 mph, and he's saying "You! Shall not! Paaaaass!". You would think it wouldn't be much of a problem, but here's the thing: Cycling is a dynamic experience, especially in hilly areas. You naturally gain speed on the downhill, and it builds momentum to help you partway up the next hill. But with the speed limit throwing a wet blanket on all that, you find yourself at the bottom of the hill with very little momentum gained, and you have to make up for it on the uphill because of the inertial you didn't get. At the recommended settings, the upgraded system fights against hills, while the original Rad system flow with them. Despite having much more power now, my laps around the usual 8 mile course I take were slower, and the ride left me more tired.

Kyle to the rescue
I was not successful in getting information elsewhere, so I reached out to Kyle of Bolton Ebikes. Kyle has THE best video on the controller upgrade displays, and he pointed me to setting P3, which is the "Power assist control mode". The default setting is 0, which places an individual speed limit on each PAS level, and it also ties the throttle to the PAS limits. Changing P3 to 1 sets the speed limit to the general top speed, and disconnects the throttle from the PAS levels so it works all the time up to full power, regardless of the PAS level. I agree with Kyle that this is the more "intuitive" way to set it.

So this fixed two major issues, but two issues remained: Noise, and poor battery life. Last week I rode this same bike, with the original controller, several times through a metro park and a connected state park. After 32 miles, the battery was at 40%. With the upgraded controller, the battery was empty at 24 miles.

Then there is the noise. The stock Rad setup is fairly quiet for a geared motor, and this is a result of the refined programming and optimization. Riding though the woods with an occasional pedestrian, they would either not hear me approaching, or hear the blended sound of the tires and motor.. With the upgrade, the motor is loud and rough like a stepper motor, and people turn around to see what the noise is. Now, I played with the settings further, and found that I could change the maximum power settings, and also how aggressively the bike accelerated, but nothing could get rid of the noise, which is bad enough to rattle my fender supports.

I ended up swapping the controllers and displays multiple times to make adjustments and comparisons. You CAN make the upgrade controller behave almost like the original Rad controller, but what's the point of the upgrade then? True, you could mimic the Rad performance, then change the settings to high performance when your buddies want to go off-roading or horsing around. But, you still have to deal with the noise and battery life. In the end, it was mostly the noise that made me go back to stock.

In conclusion, I like many aspects of the controller upgrade. The acceleration is great, hill climbing is amusing, and off-roading is almost like having a 2 stroke blasting though the leaves and gravel. Whether or not this upgrade suits you depends on your use, and it would be great for local commutes, running errands, hauling groceries, dealing with exceptional hills, or just having fun on local trails. It it a high quality and reliable product, and if it fits your style, get it. But, it's not everyone's style, and if you are more into cycling for pleasure, getting back into shape, or need to cover long distances, the original Rad setup may suit you better.

PS: Just as little update on the status. With winter now being on the scene here, I've decide to leave the upgrade in place. The 25 amp version was not worth the range loss and noise, and if that was all I had I'd probably be sticking to the original controller all the time. However, the 35 amp version is more efficient than the 25, and the extra power makes the noise more tolerable. The other factor is there are fewer other people sharing the bike paths, and with more time being spend on desolate routes, I'm using the cruise control more. We shall se when summer rolls around, and more people are enjoying the peace and quiet. But for now, the extra power comes in handy slogging through mud and snow.

[Altema]

By the way, I did a deep dive on some of the more useful settings, and thought I'd document them.

The C14 setting is not mentioned most of the time, but it adjusts the pedal assist levels. The settings are 1, 2, and 3, with each level increasing the power of the PAS levels. 2 is default, but I changed mine to 1 to get the PAS closer to how I usually ride.

Setting C5 changes the maximum power sent to the motor, but the manual did not mention the special functions of settings 02, 01, and 00. Those last three deliver full power, but with a curve that builds up to full power. This curve is based on time, not speed, so if you are already going 10 mph, it still takes the same amount of time to get to full power. This is useful if you don't want to get hit suddenly with full power, like when carrying a passenger or cargo.

C5 (Controller Maximum Current Adjustment Mode, 00 - 10)

  C5=10: 1200 watts, 1170 watts observed
  C5=09: 1176 watts, 1070 watts observed
  C5=08: 1128 watts, 1010 watts observed
  C5=07: 1056 watts, 960 watts observed
  C5=06: 960 watts, 930 watts observed
  C5=05: 840 watts, 880 watts observed
  C5=04: 696 watts, 770 watts observed
  C5=03: 528 watts, 570 watts observed
  C5=02: 1150 watts observed, soft start
  C5=01: 1150 watts observed, softer start
  C5=00: 1150 watts observed, softest start

[FortunatelyTheMilk]

Nice work! It's been a while since I tinkered with the setting on mine, but I didn't get mine right straight out of the box, though I did use the Bolton video as a starting point.

Currently I've disabled the throttle (for local compliance) and dialled the power and PAS all the way to 11, and then leave it in PAS 2 for most of the ride, which still gives me lots of range.

I rarely use PAS 5 from a standing start, it's too easy to pop the front wheel off the ground, or to strip a gear in the motor. But it's nice to have when you want more oomph!

[Altema]

Nice work! It's been a while since I tinkered with the setting on mine, but I didn't get mine right straight out of the box, though I did use the Bolton video as a starting point.

Currently I've disabled the throttle (for local compliance) and dialled the power and PAS all the way to 11, and then leave it in PAS 2 for most of the ride, which still gives me lots of range.

I rarely use PAS 5 from a standing start, it's too easy to pop the front wheel off the ground, or to strip a gear in the motor. But it's nice to have when you want more oomph!

I don't think I've even used PAS 5, except to try it out, lol. Just used PAS 4 for the first time last week! It came in handy today though. I was riding a long uphill grade straight into a howling headwind, but I hit the button and fixed THAT!

And if anyone had called out "You're cheating!" at that moment, I would have said "Yes I am!".

[George3]

Altema,

A well written, detailed and useful review.  I greatly appreciated your impressions about the drivability and overall behavior of the bike after the modifications.  Given my ride style and the terrain I am in, I think I will just keep the bike controller stock. However, I am grateful for you taking the time to spell things out so that I could make a better decision.

[sc00ter]

Nicely written review and thanks for taking the time to share your findings!

[spyder918]

I'm assuming this is the Bolton upgrade?  I didn't quite have 'wheel popping' torque like you.  Maybe because you have the RadMini.  Did you notice any speedometer issues?  With mine, I couldn't get the MPH to stop jumping all over the place.  It seemed just buggy to me.  Other than that I love the upgrade.

[FortunatelyTheMilk]

Did you change the P2 settings? I had to try a couple before I got mine to work.

[Altema]

I'm assuming this is the Bolton upgrade?  I didn't quite have 'wheel popping' torque like you.  Maybe because you have the RadMini.  Did you notice any speedometer issues?  With mine, I couldn't get the MPH to stop jumping all over the place.  It seemed just buggy to me.  Other than that I love the upgrade.

This controller and display were from Electro Bike World, but Kyle from Bolton was the one who helped me out. The controllers from Bolton and Electro Bike World appear to be from the same manufacturer. The RadMini has smaller diameter wheels than the RadRover, so that would give it a significant mechanical advantage. The Rover with 26" wheels would have 76.92% of the torque of the Mini, if my math is correct, but that's based on the radius of the rim instead of the axle centerline to the outside of the tire.

I did not have any issues with the speedometer, aside from not responding as quickly as the stock setup. No jumping around though, so you may want to check the P2 setting like FortunatelyTheMilk suggested. I really liked the power of the upgrade, and if there was a way to get rid of the extra noise, I'd switch back. I contacted the company (EBW) about the noise, and am waiting to hear back.

[Altema]

Minor update: I contacted the company I bought the upgrade from, and let them know about the problem with the noise. They suggested the issue may be my motor, and I should replace it with a new one. I wrote back that the motor was only 3 months old, and worked like new when I put the Rad controller back in. I suggested that perhaps the controller output was modified sine wave instead of actual sine wave (it's cheaper that way), or that there was a problem with the controller. Waiting on a response.

The power levels I can control as needed, and that will probably help with the poor battery life, but the noise is always there and can't be changed.

[Altema]

Breakthrough!
I found out that the upgrade controller uses a modified sine wave output, which is also known as a trapezoidal waveform. Instead of a smooth sine wave, the trapezoidal output turns on and off rather abruptly, and that does indeed cause extra noise. Rad controllers use pulse width modulation to simulate a more accurate sine wave for the motor. It's more expensive, but quieter and smoother.

I also heard back from Electro Bike World, and they offered to send me the 35 amp controller to try and see if it's quieter. Being more expensive, it may have more FET's (Field Effect Transistors), which would smooth the waveform and be quieter.

I plan on connecting the cables and doing a bench test with all three controllers, but either way, it was generous of Electro Bike World to make the offer.

[Altema]

The upgrade kit was installed for the 4th time, and here's some additional observations.
I went on a "power ride", doing jumps and flying across intersections, even rode a mountain bike trail, and the kit is well suited for this type of riding.
Then I dialed the power down to 570 watts maximum, and was pleased that it could still reach top speed under throttle. However, it struggled to climb hills, and PAS level 3 was inadequate.
The Rad controller is more efficient. Even with the upgrade controller limited to 570 watts, it delivers about 15 fewer miles per charge.
I gave a girl a ride with my rack seat installed, and she said the vibrations tickled! Is that a feature? Seriously though, the vibrations are strong enough to feel in the handlebars, so they are significant.
There are control settings that get rid of lurching, and those are the "C5" settings of 02, 01, and 00. At any of those settings, the power sent to the motor is softer at first, then increases. 02 is similar in feel to the stock rad controller, and the other two are softer and softest.

The larger 35 amp controller will be here is a few days. I know it won't use the more expensive PWM sine wave simulation that Rad uses, but if it has more field effect transistors, that will give it a less-crude output waveform and it should be quieter. When I discussed it with Kyle from Bolton, he said it's likely they use the same waveform though, and he's probably right.

[Griz]

I have a question on the main plug.  You said you had to run the controller cable to the display.  I plan on upgrading my wife's Mini, but when I did my rover the controller cable plugged into the harness at the frame.  I didn't have to run anything

[Altema]

I have a question on the main plug.  You said you had to run the controller cable to the display.  I plan on upgrading my wife's Mini, but when I did my rover the controller cable plugged into the harness at the frame.  I didn't have to run anything

I plugged into the harness at the frame, but the cable was too short. I had to run it around the front of the controller, and make a loose loop with the cable tie to hold it.

[Loulou718]

Thank you so much for the review and updates. I have a mini I plan on upgrading as well but Im nervous about the 35 amp wire being too short on the controller and having to solder the wires together to make an extension? So you didnt have to do that to the 25 amp controller?