Overheating middrive motor?

Joined
Feb 6, 2019
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333
Today I was pushing my bike really hard and eventually I stopped and sat down next to the bike to get some water. I realized while I was sitting next to it that I could literally feel the heat radiating off of the motor. Being the curious and impulsive idiot I am, I touched it with my bare hands, and it was very very hot, I'm sure I could have cooked something on it and would have burned my hand if I kept it there any longer. Is this normal? The motor is a mini cyclone with the stock controller, (slightly smaller version of the cyclone 3000) and I'm running 2400 watts through it. When I first began riding this bike about 200 miles ago I was keeping my rpms way too low even on hills, (which I now known is a big no-no especially with this motor) and I noticed that the system would shut itself off if it got extremely hot. I'm pretty sure it still does this but I haven't reached that threshold for a while. Do you guys think this is a good enough protection system? I'm not entirely sure how it works, I don't know whether there is actually a temperature sensor in the motor or whether it's just sensing the temperature of the controller, but I definitely don't want to melt my motor. What do you guys think?
 
Sure, it's a good enough system to prevent immediate failure. But really you shouldn't be bumping into that in regular use, constantly running at 100C is going to shorten it's life.

Make sure you're running in the correct gear, and make sure the heat dissipating parts of the motor are clean. I've put over 26,000km on my BBS02, and I can count on one hand the number of times it's been "hot", generally only when I'm testing a battery or something.

It really comes down to how long you want it to last.
 
dustNbone said:
Sure, it's a good enough system to prevent immediate failure. But really you shouldn't be bumping into that in regular use, constantly running at 100C is going to shorten it's life.

Make sure you're running in the correct gear, and make sure the heat dissipating parts of the motor are clean. I've put over 26,000km on my BBS02, and I can count on one hand the number of times it's been "hot", generally only when I'm testing a battery or something.

It really comes down to how long you want it to last.

Thanks! I was worried I wasn't going to get any replies. I believe I've reached that cut off point three times when I was first riding the bike, I was lugging the motor too much. Is 100C the highest these motors can generally handle? I know they probably vary from motor to motor. And wow, 26,000 km is a lot. I do hope my motor lasts that long, not sure that it will though, BBS02s are supposed to be more reliable I think.
 
You killed your motor... It to late
I not not going into any more then you push to hard. No fan cooling Heat kill this motor...
Heat sink are useless

Copy me or other es poeple

They help me when I started

Save up for new motor.

Good luck
 
I would try to keep the temp under 60C. Around 125C, you might lose the hall sensors or demagnetize the magnets.
It sounds like you have it geared too fast. Use lower gearing if possible. Another big factor is air speed over the motor. Anything to get more air over it will help a lot.
 
Lower gearing or less amps.. your motor is not up to the task of the power being put through.
If the case is too hot to keep your hand on, it's very likely over 100C inside, which is the point at which most motors start to take damage.

Is this the luna cycles mini cyclone kit? because some complaints about it the motor not being rated for the load floating around the internet.. ( not uncommon - luna exaggerates a lot of their specifications.. )
 
lower gearing or less amps.. your motor is not up to the task of the power being put through it.

Is this the luna cycles mini cyclone kit? because some complaints about it the motor not being rated for the load floating around the internet.. ( not uncommon - luna exaggerates a lot of their specifications.. )
 
Looking at the luna website, they claim it's a 2000 watt motor ( realistic continuous wattage is probably much lower than that ) and you're running 2400w through it..


Now, if you go look through cyclone taiwan ( the source of all these parts ), you'll see that their biggest motor is rated at ~1600w. The 'max output' figure of 2400w is probably a few minute peak.

http://www.cyclone-tw.com/motor.html



I do not have a dyno graph for this motor nor experience with it.. but if you want it to survive, i'd tune the amperage down or change the gearing and see what the heat is after that..
 
Not to be harsh but if you wanted a +2kw motor you should have bought one. Even 1.6kw is pushing it for the mini.

As far as I know there is no thermal rollback or cutout for the motor on any Cyclone, so you've definitely caused permanent damage.
 
Grantmac said:
Not to be harsh but if you wanted a +2kw motor you should have bought one. Even 1.6kw is pushing it for the mini.

Well, noob is in his username :mrgreen:. Unfortunately many of us come here because we learned something the hard way!

Usually a 2kw motor is a 2kw motor.

I talk about common vendor fibs here. Maybe OP will find it useful:

[youtube]JPmA4L7L2G0[/youtube]
 
The cyclone mini motors have a bi metal strip (like a kettle) temperature sensor. On the controllers from cyclone in taiwan the controller switches off when the motor overheats.

Luna seem to be using a different controller so not sure if they are doing the same but if you experienced complete power cut outs with a hot motor its a good bet they are.

For sure try to avoid hitting that limit in the first place. Lots of these motors have burned out even with that mechanism in place.
 
aCeMadMod said:
You killed your motor... It to late
I not not going into any more then you push to hard. No fan cooling Heat kill this motor...
Heat sink are useless

Copy me or other es poeple

They help me when I started

Save up for new motor.

Good luck

Motor stills runs okay though and pulls as hard as the day I installed it, don't think I killed it yet?
 
Grantmac said:
Not to be harsh but if you wanted a +2kw motor you should have bought one. Even 1.6kw is pushing it for the mini.

As far as I know there is no thermal rollback or cutout for the motor on any Cyclone, so you've definitely caused permanent damage.

Yeah I know lol, I did want a tiny motor but I guess I can't have everything. The motor still does run though, and it seems to run normally, like the same as when I first installed it. Maybe I'll install a temperature sensor or something, but I need to figure out the max temp I can safely take it to though.
 
district9prawn said:
The cyclone mini motors have a bi metal strip (like a kettle) temperature sensor. On the controllers from cyclone in taiwan the controller switches off when the motor overheats.

Luna seem to be using a different controller so not sure if they are doing the same but if you experienced complete power cut outs with a hot motor its a good bet they are.

For sure try to avoid hitting that limit in the first place. Lots of these motors have burned out even with that mechanism in place.

I haven't hit that limit in a while, I've been trying not to abuse the motor. Is it possible that the "temperature" sensor is actually just for the motor controller though? It seems more likely than the motor having one, since these things seem too basic for that, but at the same time, I haven't modded the controller or anything so it should be running cool
 
fechter said:
I would try to keep the temp under 60C. Around 125C, you might lose the hall sensors or demagnetize the magnets.
It sounds like you have it geared too fast. Use lower gearing if possible. Another big factor is air speed over the motor. Anything to get more air over it will help a lot.

Okay, sorry I'm very new at this so if any of this sounds stupid that's why. Would running a tiny fan to push air onto the motor actually do anything cooling wise? I'm also considering lowering the gearing anyways so I might just do that.
 
neptronix said:
Lower gearing or less amps.. your motor is not up to the task of the power being put through.
If the case is too hot to keep your hand on, it's very likely over 100C inside, which is the point at which most motors start to take damage.

Is this the luna cycles mini cyclone kit? because some complaints about it the motor not being rated for the load floating around the internet.. ( not uncommon - luna exaggerates a lot of their specifications.. )


Lol, I thought luna was supposed to be one of the more honest ones. I think I'll reduce the gearing, I just don't want to put too much torque on the gears and stuff. I think I'll install a temperature sensor maybe on the motor so I'll know when I'm pushing it too much.
 
neptronix said:
Grantmac said:
Not to be harsh but if you wanted a +2kw motor you should have bought one. Even 1.6kw is pushing it for the mini.

Well, noob is in his username :mrgreen:. Unfortunately many of us come here because we learned something the hard way!

Usually a 2kw motor is a 2kw motor.

I talk about common vendor fibs here. Maybe OP will find it useful:

[youtube]JPmA4L7L2G0[/youtube]

Yeah, this is my first e bike build and I've made so many mistakes that I've lost track. :( I did learn a lot more about these bikes than I expected to though even if it's not a lot
 
Okay I took the bike out today and rode with the throttle pinned many times to try and mimic the hardest type of riding I would do. (still never lugged the motor by keeping it in too high of a gear, always kept the revs up) I went up the steepest roads I could find which are pretty steep (because I live close to Santa Cruz) with the throttle pegged completely open. The highest I could get the outer motor casing to is 145 degrees Fahrenheit, or around 62 degrees Celsius. Granted it was only 65 degrees today outside, but I rode it as hard as I could and would. No idea whether 145 degrees Fahrenheit is a safe temperature or not, I think someone said 60 degrees celsius is the hardest you want to push it which is around what this is. Also how would I know if the motor is damaged though? It feels fine to me, there's nothing that would indicate that from what I could tell.
 
The two common heat damages are:

--magnets demagnetizing to some degree; this causes the motor kV to change, which makes it faster with less torque. So youc an test the no-load speed of the motor after an overheating event, and see if it is different than it was before that.

--hall sensor failure; this is generally obvious when it happens. Sometimes it only happnes during the overheat, and comes back afterward, more often it is permanent damage requring sensor replacmeent.


If you need to cool the mtor, there are a number of threads out there about cyclone motors that discuss cooling methods; you can also look up the RC motor cooling mods, as those may be similar enough to adapt.
 
amberwolf said:
The two common heat damages are:

--magnets demagnetizing to some degree; this causes the motor kV to change, which makes it faster with less torque. So youc an test the no-load speed of the motor after an overheating event, and see if it is different than it was before that.

--hall sensor failure; this is generally obvious when it happens. Sometimes it only happnes during the overheat, and comes back afterward, more often it is permanent damage requring sensor replacmeent.


If you need to cool the mtor, there are a number of threads out there about cyclone motors that discuss cooling methods; you can also look up the RC motor cooling mods, as those may be similar enough to adapt.

Just checked and it's pretty much exactly the same. It was a tad lower actually because I tested it on a slightly discharged battery. I could've swore I felt a bit less torque when I went out today but it wasn't on a fully charged battery plus I rode mostly uphill today and I'm probably just imagining things.
 
speedyebikenoob said:
amberwolf said:
So youc an test the no-load speed of the motor after an overheating event, and see if it is different than it was before that.

Just checked and it's pretty much exactly the same. It was a tad lower actually because I tested it on a slightly discharged battery. I could've swore I felt a bit less torque when I went out today but it wasn't on a fully charged battery plus I rode mostly uphill today and I'm probably just imagining things.
Sounds like the complete opposite of a no-load test.

A loaded test is a bad comparison because there are too many factors (including what gear you're in) involved.

A no-load test of *just the motor*, before and after, is needed for a certain comparison.
 
amberwolf said:
speedyebikenoob said:
amberwolf said:
So youc an test the no-load speed of the motor after an overheating event, and see if it is different than it was before that.

Just checked and it's pretty much exactly the same. It was a tad lower actually because I tested it on a slightly discharged battery. I could've swore I felt a bit less torque when I went out today but it wasn't on a fully charged battery plus I rode mostly uphill today and I'm probably just imagining things.
Sounds like the complete opposite of a no-load test.

A loaded test is a bad comparison because there are too many factors (including what gear you're in) involved.

A no-load test of *just the motor*, before and after, is needed for a certain comparison.

No, I did do a no-load test, sorry, I worded it weird. I meant I went for a ride then got back and lifted the bike of the ground and measured the motor speed. I had measured the motor speed a couple months ago and found it to be almost exactly the same. (This time rpm was a little lower because of the slightly discharged battery) I just meant that when I went for a ride earlier today it *felt* like it had a tiny bit less torque, but I'm pretty sure I'm imagining things because I've felt like this before with my bike lol. 272 rpm at the crank when I measured 2 months ago and 260 rpm this time. Battery was at 66 volts when I measured it 2 months ago and this time it was at 63.
 
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