Radrover Controller & Display Upgrade Kit

thatdude902

Active Member
Yeah, 1600W is a lot of power, thus a lot of heat generated. I've read some people caution about melting the nylon gears (remember those when replacing the motor?). That's why I was a little worried about smelling something. At least we have a spare set of nylon gears from the old motor.
 

spmckinnon

Member
Yeah, 1600W is a lot of power, thus a lot of heat generated. I've read some people caution about melting the nylon gears (remember those when replacing the motor?). That's why I was a little worried about smelling something. At least we have a spare set of nylon gears from the old motor.
Tried out setting c5 lower, great call, the bike is much smoother and less jerky. And you're right, you still get to keep the same to speed.
 

AHicks

Well-Known Member
That's the sort of setup option the KT controller/LCD display allows. It really takes time to figure out what it can and cannot do. Keep messin with it. You'll have a bike performing EXACTLY like you want it to.
 

spmckinnon

Member
Even with the reduction in power by changing that setting, I've noticed that the motor is very hot to the touch after a 25-kilometer ride in 30 degree celsius heat with some hills and mostly full throttle. So hot I can barely keep my hand touching the outer casing.

What are safe operating temps?
 

AHicks

Well-Known Member
Keep in mind that your motor is only rated for 750 watts. Yes, it'll hold up to much higher, but the question is how long? Over 750 watt power settings should be a temporary thing. It's not going to hold up to even 1200 watts for extended rides. Every time you turn the wick up to 1200+ watts, it needs to be followed by a cool down period. The motor, at 750 watts, can hold it's own. At higher settings, it's going to start building up heat it cannot get rid of fast enough. If it WAS able to get rid of heat faster, it would carry a higher wattage rating.
 

spmckinnon

Member
I typically run at around 900W on flats, shoot upto 1200W on hills and everything else below 750W. On average though I'm trying to keep it around 800 - 900.

Maybe I can install a motor temperature setting to be safe? Anyone done that before? Is it even possible?
 

AHicks

Well-Known Member
I understand some higher end controllers are able to taper the amount of available power if things get warm inside the motor - among other things. The beauty of the KT based controllers (like Bolton's) is a much greater degree of control than the factory controllers have over a lot of different aspects, but there are controllers where that greater amount of control is just a start. Programming them, with my understanding of what's possible, is going to invlove an understanding of electrical engineering WAY beyond my comprehension.

Your typical 900w plus usage settings are causing the 750w motor to build up heat. The ONLY way to get rid of that heat is usage well below 750 watts that will act as a cool down.. The motor is able to handle only 750w on a constant basis. Any setting over that is going to cause heat to accumalate, and will eventually require a cool down period, likely much longer than it took to build the heat - OR - risk of melt down is likely. If you keep riding it like you are now, I'm thinking you're going to be needing another motor soon...
 

spmckinnon

Member
Thanks @AHicks and @thatdude902 for the info.

Today I took the motor setting power down further to 7/10 and rode into work at PAS4. This keeps the motor around 700W - 800W. When I need additional power briefly for say climbing a hill or trying to make a light, I'll switch to PAS 5 or just twist the throttle which brings the power to 1200W but I'll only stay at this elevated wattage for a short period.

After my 25km commute in 20C weather this morning, the motor was only slightly warm to the touch. Similar to what it was at stock.

This is probably a much better approach for the longevity of the motor. I'm glad I asked before I melted the thing. Damn, I've been riding it like I stole it for months, I wonder if I've already done some damange. Seems to be running smoothly now though.
 

Timpo

Well-Known Member
But how long do you actually hit 1600W??

Like 1 or 2% of your riding time?

It's not like you're hitting 1600W all the time.
 

spmckinnon

Member
But how long do you actually hit 1600W??

Like 1 or 2% of your riding time?

It's not like you're hitting 1600W all the time.
When I first did the motor upgrade I was trying to hit 1600 as much as possible, I wanted to go as fast as possible all the time. I was probably hitting 1600 only on the hill climbs.

Now I only hits 1200 or 1400 maybe 5% of the time.
 

Feliz

Well-Known Member
I've never found temperature to be a big issue, I have two mid drives I monitor and I've never seen the temperature over 40C running them mostly between 700 and 900 watts with periods up to 1500 for hills etc. I check my rear drive hub motors with a infra red thermometer and even my 500 watt Radrover using Bolton's kit running at 1500 watts I've never seen alarming temperatures. And no, I'm not really a temp freak I just got in the habit when I used to rebuild motorcycles and I would watch temps in the the air cooled bikes after a rebuild. Oh, I typically wouldn't go riding with temperatures much over 30C.........I'd rather drink beer.
 

thatdude902

Active Member
Here the difference is some of us are running hotter motors (bigger magnet 750w) plus 52 volt batteries with our Bolton kits.
 

AHicks

Well-Known Member
I've never found temperature to be a big issue, I have two mid drives I monitor and I've never seen the temperature over 40C running them mostly between 700 and 900 watts with periods up to 1500 for hills etc. I check my rear drive hub motors with a infra red thermometer and even my 500 watt Radrover using Bolton's kit running at 1500 watts I've never seen alarming temperatures. And no, I'm not really a temp freak I just got in the habit when I used to rebuild motorcycles and I would watch temps in the the air cooled bikes after a rebuild. Oh, I typically wouldn't go riding with temperatures much over 30C.........I'd rather drink beer.
I think the heat issue might be more likely to become obvious on your RAD gear drive if you could find an area that would let you run at a load of 1200+ watts for a while. Like 15 minutes or more?

My understanding is that the gear drives have a terrible time transferring heat to the outside case, where your temp gun can read it - which may be leading to a false sense of security. I'd sure like to be wrong here.

I have a 1500w direct drive now, and in a search for a better understanding of what's going on with the gear driven rear hubs (proably a MAC 12t) with similar (or hopefully much better) performance in the 7-15 mph range where I spend most of my time, been doing a bunch of research. From what I can find, the gear drive offers much better performance - BUT - you need to be careful comparing that performance to the direct drive, because the direct drive is MUCH better at getting rid of heat. So the gear drive has better performance, but it's about short sprints. The direct drive will carry higher wattage settings for a longer period. Another compromise situation..... -Al
 

Feliz

Well-Known Member
I think the heat issue might be more likely to become obvious on your RAD gear drive if you could find an area that would let you run at a load of 1200+ watts for a while. Like 15 minutes or more?

My understanding is that the gear drives have a terrible time transferring heat to the outside case, where your temp gun can read it - which may be leading to a false sense of security. I'd sure like to be wrong here.

I have a 1500w direct drive now, and in a search for a better understanding of what's going on with the gear driven rear hubs (proably a MAC 12t) with similar (or hopefully much better) performance in the 7-15 mph range where I spend most of my time, been doing a bunch of research. From what I can find, the gear drive offers much better performance - BUT - you need to be careful comparing that performance to the direct drive, because the direct drive is MUCH better at getting rid of heat. So the gear drive has better performance, but it's about short sprints. The direct drive will carry higher wattage settings for a longer period. Another compromise situation..... -Al
Good point, I have an Elby with a BionX DD and even after extended use its only warm to the touch.
 

Feliz

Well-Known Member
Here the difference is some of us are running hotter motors (bigger magnet 750w) plus 52 volt batteries with our Bolton kits.
Watts are Watts, higher voltage just means less amps, heat should be the same, now if you were running 3000 watts that's different.
 

thatdude902

Active Member
Higher speed equals higher RPM inside the motor, more frictions & heat in the bearings & nylon gears. There is at least a 7 mph difference from my own observation between a stock motor with the Bolton kit vs 750w motor + 52V with the Bolton kit.
 

Feliz

Well-Known Member
Higher speed equals higher RPM inside the motor, more frictions & heat in the bearings & nylon gears. There is at least a 7 mph difference from my own observation between a stock motor with the Bolton kit vs 750w motor + 52V with the Bolton kit.
Higher speed equals higher RPM inside the motor, more frictions & heat in the bearings & nylon gears. There is at least a 7 mph difference from my own observation between a stock motor with the Bolton kit vs 750w motor + 52V with the Bolton kit.
And what was the temperature difference?
 

AHicks

Well-Known Member
There would be no temp difference unless your average watt usage was running higher. Many who install Bolton's kit will not use more power. A short burst of power to squirt across a busy street, at an acceleration rate and power level that was not available previously, is not going to raise your motor temp noticeably. In spmckinnon's notes above, you can see the result of continuous high power usage that was not available (or adjustable) previously. His notes make it sound like he was running dangerously hot - to the point of a burn down.

As a self confessed temp freak, I'd be interested if you noticed much difference before/after kit install?
 

thatdude902

Active Member
2 people running 52v + 750w motor already reported heat issues. I smelled burning plastic, spmckinnon's motor was hot to the touch. Mine is now already turned down, I am not going the risk melting nylon and turn the power back up just to get data.
 

spmckinnon

Member
Yeah, I'll eventually install a temp sensor inside the motor since the Bolton controller supports it.

Does anyone know what safe operating temperatures are for these Bafang 750W Brushless Gear Hub Motors?