Upgrading a Radrover to 30 mph top-speed

[walawn]

Goodday gentlemen. First post to the forum and looking for some technical advice already. I recently purchased a Radrover from Rad Power Bikes. It performs like a DIY bike with a 750W geared Bafang rear hub motor, 48V 11.6 Ah dolphin battery, and a controller rated for 30 Amps (but I think runs around half that). The tech specs are below:

http://www.radpowerbikes.com/pages/radrover-technical-specs

I'm looking to increase the top speed to 30 mph. I know this may not be possible with the motor in the rear since it seems to be wound for 20 mph from the factory and kind of putters out past that point. I raised the top speed in the LCD settings to 40 kph (24.85 mph) and it shows around 22-24 on the speedometer under full throttle on flat ground with my 180 lbs on the seat. I feel like the cheapest way to achieve a higher top speed (or even attempt this) is to change the controller out to one that allows for higher Amps. The problem is that I have no clue what controller to try and install. Any help or advice would be much appreciated. I am a motorcycle tech, but the world of ebikes is still very new to me. I am also aware of a 52V dolphin pack from Luna Cycle which should just be plug and play as well which might help me with this problem. Thanks guys!

 

[d8veh]

I can't understand what you're saying. How can it be wound for 20 mph if it does 24 mph with you sitting on it?

You lift the wheel off the ground and spin it up to maximum with the throttle. Whatever speed it reaches is its maximum speed.

Your controller is 22 amps, which is about the maximum you can take from the battery, so if you want 30A for faster hill-climbing, you'd need a new battery too.

The only way to get that motor to 30 mph is to get a 60v battery. 16S lipos will do it, which will give about 64v.

 

[Syonyk]

More amps on the controller won't affect top speed. You need more voltage to counter the back EMF.

The bike has a 36v pack. I wouldn't try to push 60+v through it, but I suspect it might take mid-50s just fine. Be aware that you may fry something and need to replace the controller if you experiment with voltage.

 

[wineboyrider]

14s liion or 14s lipo max probably as the controller probably has 63v caps.

 

[walawn]

More amps on the controller won't affect top speed. You need more voltage to counter the back EMF.

The bike has a 36v pack. I wouldn't try to push 60+v through it, but I suspect it might take mid-50s just fine. Be aware that you may fry something and need to replace the controller if you experiment with voltage.

The bike has a 48V pack actually, not 36V. The OEM battery is 48V 11.6Ah Li-ion with 30 Amp Continuous BMS Samsung 29E Cells. It's 54.6V when I take it off of the charger. It should handle a 52V pack just fine. I need to know what controller to buy to run more amps and go to higher volatages (i.e. 60V+).

It should take this pack just fine which would give me a little better performance:

http://lunacycle.com/batteries/packs/52v/52v-pansonic-11-5ah-or-13-5ah-dolphin/

Here is a post of me changing the case on the stock battery on another forum:

https://electricbikereview.com/community/threads/changing-the-48v-dolphin-battery-case-on-the-radrover-step-by-step.4444/

 

[walawn]

14s liion or 14s lipo max probably as the controller probably has 63v caps.

I took the controller off the other day to install a bag around the battery and it is rated for 30 amps. Dunno about voltage specs.

 

[walawn]

I can't understand what you're saying. How can it be wound for 20 mph if it does 24 mph with you sitting on it?

You lift the wheel off the ground and spin it up to maximum with the throttle. Whatever speed it reaches is its maximum speed.

Your controller is 22 amps, which is about the maximum you can take from the battery, so if you want 30A for faster hill-climbing, you'd need a new battery too.

The only way to get that motor to 30 mph is to get a 60v battery. 16S lipos will do it, which will give about 64v.

My speedometer could be off as well. I have the LCD display set for 27 inch wheels, but my Kenda Juggernaut tires measure 29" when fully inflated. I rode with a Stromer ST1 the other day and he thought that I was going faster than what my max speed said on the display (i.e. 22-24 mph approximately). He could do 28 mph pedal assisted and said he was having trouble keeping up (He was 60 though and I'm 32 but he was a machine for sure lol). The motor has tons of torque (750W geared Bafang hub) up to 20 mph and then the power really tapers off. It takes a while to get to top speed, hence why I said that it is wound for 20 mph.

 

[d8veh]

You need 16S to get that bike up to 30 mph. That 52v one is only 14S, which will give you 7.6% more speed. 16S will give 23% more.

 

[Syonyk]

Assuming the controller can take it.

I wouldn't feel comfortable pushing a sub-60v controller above 60v, given how many components top out at 60v or 63v or 65v. Pushing 67+v into an unknown isn't likely to end well.

 

[walawn]

You need 16S to get that bike up to 30 mph. That 52v one is only 14S, which will give you 7.6% more speed. 16S will give 23% more.

Thank you for the great advice. I also just switched my tires to 26 x 2.5 Maxxis Hookworms which dropped my top-speed as well. I have more torque though!

 

[walawn]

Assuming the controller can take it.

I wouldn't feel comfortable pushing a sub-60v controller above 60v, given how many components top out at 60v or 63v or 65v. Pushing 67+v into an unknown isn't likely to end well.

I want to change the controller. I just have to figure out what works with the 750W geared Bafang hub motor and King-Meter SW-LCD.

 

[docw009]

The sondors upgrade controllers sold by Luna should be compatible. I believe that bike uses the same G06 series motor, except it's 250 or 350 watts. Does your Radover have the small round quick connect on the hub? Whether you can go 30 mph, I dunno. Luna claims their upgrades approach that speed. You might have to buy it with their display though. Ask their tech support.

 

[walawn]

This is the motor I have:

http://www.szbaf.com/en/components/component/motor/rm-g06750dc.html

I have a 20 Amp controller and 52V battery on the way. Should that net me 1000 Watts (1040 with a perfect conversion of 20A x 52V)? And maybe get me to 30 mph? I know that the battery will be closer to 58V when fully charged so maybe even more performance will result.

 

[Chillax]

Hey - I am hoping to do the same thing with my new RadMini. Were you able to get this working??

 

[docw009]

If I remember what happened, walawn's motor was sensorless, so the Luna 25A controller, which requires Hall sensors, wouldn't work. The Bafang motor on my fatbike does use Hall sensors, so I was able to install the Luna controller last summer. It works fine, and I can get an indicated 26 mph on 52V.

Thing is, the Luna Controller was designed to be plug compatible with a Sondors. I don't have a Sondors. Install was a bitch. The motor connection was fine, but everything else was a little different. Cable lengths were wrong. The throttle is different. I had to chop up the Luna harness, figure out the throttle, and rewire it to fit my controls. You don't want to do this.

Unless you can find a third party controller with the same connectors, expect to do splicing. So I would advise against it on a newly bought ebike. FInd out instead if there is a programmed speed limit on your radmini, and whether you can up the voltage on the battery,

 

[torker]

I ended running 15s lipo on my 9c . I added a 18or 20 awg wire to my shunt. I need a disclaimer : Just because I got away with it doesn't mean you will.. I also have my 9c laced to 20" It gets going pretty quick. The heaviest load doesn't last long.