Ebike Hub Motor overheating cooling solution - HUBSINK OFFICIAL THREAD

rberger maybe yet another hubsink is what you need? Didn't catch what motor you run, but if you got enough width between motor flanges to fit two hubsinks side by side that should help with the added thermal mass. Heat should be drawn even faster out from the motor. Worth trying as you say, depending on where thermal rollback happens the rollback could be hi risk. Better to try to avoid thermal rollback.
 
Hi Robert:

West Coast Electric Cycles will soon have in stock a 45mm stator DD hub motor.

https://westcoastelectrics.com/product/45mm-ddhub/

This one may be your best option, although I still doubt it will get you up your hill without your pedaling at least a little bit. I recommend the "4T" option.

You will need to check if your dropouts can spread to 142mm to get the wheel onto your trike, and you should check freewheel and disk brake compatibility. You will definitely need to use supplementary torque arms with this motor, one on each side.
 
mrbill said:
West Coast Electric Cycles will soon have in stock a 45mm stator DD hub motor.
This one may be your best option, although I still doubt it will get you up your hill without your pedaling at least a little bit. I recommend the "4T" option.

You will need to check if your dropouts can spread to 142mm to get the wheel onto your trike, and you should check freewheel and disk brake compatibility. You will definitely need to use supplementary torque arms with this motor, one on each side.

The rear assembly of the trike including the dropouts are aluminum so I don't think I can spread it to 142mm. It was hard to even get the 135 Crystalyte in there.

I had been thinking of the two motor solution you mentioned but that seems like overkill once I got off the hill.

It looks like the Calcium Channel Blockers they had me on really wiped me out. Haven't been on the trike since earlier this week do to being nearly incapacitated. They now told me to stop the medication and I'm hoping I can at least go up the hill with minimal stopping. Its going to be in the 70's tomorrow so will give it a try then and it will be a good benchmark to compare to the previous 70 degree ambient day without Hubsink.

The next technical thing I'm going to do is to add a fan to the rear to blow over or across the hubsinks. I usually ride with one or two "panniers" and it reduces airflow to the motor. I'm hoping some increased airflow with the Hubsink/Statorade will let me get up the hill without the motor overheating (though I will probably still need to stop for my body to rest. I'm hoping I'll eventually get strong enough to not stop)

Want to again thank MrBill and everyone who has been helping me. I'm sure I'll be adding more here and hope folks will continue to add their input.
 
macribs said:
rberger maybe yet another hubsink is what you need? Didn't catch what motor you run, but if you got enough width between motor flanges to fit two hubsinks side by side that should help with the added thermal mass. Heat should be drawn even faster out from the motor. Worth trying as you say, depending on where thermal rollback happens the rollback could be hi risk. Better to try to avoid thermal rollback.

Its a Crystalyte 3540 and there is really only room for one set of hubsink as far as I can tell.
 
rberger said:
The rear assembly of the trike including the dropouts are aluminum so I don't think I can spread it to 142mm. It was hard to even get the 135 Crystalyte in there.
If you don't need all of the axle space for a big gear cluster, you can modify the axle to fit, by extending the flat part of the axle and "moving" the shoulders inward. I did this with a grinder but you could have it professionally milled if you prefer.

https://endless-sphere.com/forums/search.php?keywords=grind*+mxus+flat*&terms=all&author=amberwolf&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
file.php
 
amberwolf said:
If you don't need all of the axle space for a big gear cluster, you can modify the axle to fit, by extending the flat part of the axle and "moving" the shoulders inward. I did this with a grinder but you could have it professionally milled if you prefer.

I would like to keep my gears if I can. When I'm not climbing the mountain, I like to have low electric assist and still pedal and I find the gears still help with that. Also so far with the motor I have, I need the gears to go up the hill still.

But again, thanks for your suggestion, really appreciated the different perspectives and ideas.
 
Depending on the space you would have left between the motor cover and the frame, once the axle is resized to fit the frame, you might be able to go with a 5 or 6 speed freewheel, vs say, an 8. It might be that even an 8 would still fit. Youd have to figure out what you'd have in advance.

Often you can customize which sprockets are on there, so you might be able to use some really large sprockets on the lowest gear, then the next one over go down in size several steps, and so on, so you still have the range of gears, just not as many increments between them.


But a bigger motor might still not be teh answer; and a bigger motor will weigh more which itself will take a bit more power to move uphill (and to accelerate from a stop).
 
Hi Robert, I too am using phaserunner hs3540 statorade hubsinks panniers and have some hills. Peak temp I’ve seen is in the 87-88 degrees range with my total weight about 125 kgs in an ambient 37 degrees. My temp doesn’t climb anywhere near as fast as yours tho even with zero pedalling and 1800w. Silly question time...your brakes aren’t binding are they?
 
Tats said:
Hi Robert, I too am using phaserunner hs3540 statorade hubsinks panniers and have some hills. Peak temp I’ve seen is in the 87-88 degrees range with my total weight about 125 kgs in an ambient 37 degrees. My temp doesn’t climb anywhere near as fast as yours tho even with zero pedalling and 1800w. Silly question time...your brakes aren’t binding are they?

That is a very helpful data point. The only real difference is my total weight is another 25kg.
I am 99.99% sure my brakes aren't binding, but will check

But it looks like that 25kg could be a pretty big factor. I just compared 125kg and 150kg with the ebikes.com trip simulator. It showed 125kg would peak around what you are seeing (~85)
Trip_Simulator_125kg.png

and at 150kg by the end of the trip it would hit 120 degrees.

Trip_Simulator__150kg.png

I will be doing another ride today and see what happens and then add a fan...
 
SlowCo said:
rberger said:
I wonder if there is a way to tell if I have lost the Ferrofluid.

Do you have a Cycle Analyst on your trike? If so, just lift the rear wheel off the ground and see what the power consumption (Amps/Watts) is unloaded at top speed. Then post here or ask Grin to confirm if that is a wattage they also see when filled with enough Ferro Fluid. The no load power consumption should be a little higher with enough FF in the hub than without or too little.

I finally ran the test.
  • Having the wheel off the ground
  • Throttle full on for about 10 seconds or more
  • CA Watts: 79 to 80
  • "Speed" 29 to 30mph

Let me know if that looks like its what you would expect with enough ferrofluid.
Thanks
 
I have no experience with this motor or ferrofluid so you'll have to email Grin and ask them. Maybe someone on here knows the unloaded wattage of this specific motor without FF?
 
rberger said:
I finally ran the test.
  • Having the wheel off the ground
  • Throttle full on for about 10 seconds or more
  • CA Watts: 79 to 80
  • "Speed" 29 to 30mph

Hi Robert:

Yes, I would say your wattage figures are about the same as mine using a wheel that I know to have sufficient amount of Statorade installed and no controller field-weakening.
 
mrbill said:
Yes, I would say your wattage figures are about the same as mine using a wheel that I know to have sufficient amount of Statorade installed and no controller field-weakening.

Thanks for the confirmation. At this point, I'm pretty sure its the extra 25kg that puts me over the edge compared to others with similar setups like yours.

My next experiment will be to try putting a fan to blow over the heatsinks. Just need to figure out how mount it appropriately.
 
I haven't put the fan on yet. Got too tied up trying to get an ESP-8266 to control it :roll:

As I think I had mentioned before, I was suspicious that the Statorade leaked out of the screw hole where the brake rotor should be mounted (Its a Grin Tech sourced H3540 motor). I originally did not have a brake rotor on the hub or anything blocking that screw hole.

I finally got around to taking the rear wheel off and putting some more Statorade (~4ml) in the Hub and I have also added a rear brake rotor as a "parking brake" for my trike, so now the hole is covered during use.

The first time up my "Big Hill" it looks like the motor operated at least 20 degree's cooler than normal by the time I reached the peak! Normally its about ~110 degrees C by the time I get to the top. This time it was less than 80 degrees.

I have to try it again to confirm, but its looking like I did indeed lose a good amount of statorade earlier by not having that brake rotor screw hole covered on the hub.

My human motor still gets out of breath and I need to stop a several times going up the hill, but getting better at it! No amount of Statorade will fix that :D
 
i've been doing some more seat of the pants testing with the Hubsinks and statorade and i've found when first installing the statorade putting the whole 10ML in seems to be the sweet spot (at least for the QS205 and MXUS motors)

Some makes its way into the nooks and crannys, and seems to leave the motors with the perfect amount on the magnets which lasts much longer with 10ml than it was when i was putting in 6-7ml
 
Hey guys,
Was wondering if I could just use the heat sink and leave the feral fluid out. My hub motor only gets to a high temperature point where touching it will not burn your skin, but if you leave your finger on for a while, it will start to sting. I'm not a big fan of drilling a hole into the hub to put in FF, so if I only install the heatsink and no FF, will there be a noticeable temperature difference if I touch the motor with my finger? I know this sounds like a weird question, but I don't have any equipment to measure the temperature of my hub motor, so touching it is my only way of measurement.
 
I don't know what "feral fluid" is, but if you don't use ferrofluid (or at least ATF or some other thermally-conductive fluid) plus the heatsinks, then the heatsinks are only going to cool off the magnets and rotor ring/spoke flanges.

The stator, where the heat is generated, won't be coupled to the heatsinks by anything but air, so it won't really be cooled by the heatsinks.

You can look at the various threads about heating / cooling hubmotors, testing of such, etc., to get a better understanding of what's necessary to cool your motor.

There is also no need to drill holes; simply unbolt your motor cover to install whatever fluid you want to use.
 
BMXTiger said:
Hey guys,
Was wondering if I could just use the heat sink and leave the feral fluid out. My hub motor only gets to a high temperature point where touching it will not burn your skin, but if you leave your finger on for a while, it will start to sting. I'm not a big fan of drilling a hole into the hub to put in FF, so if I only install the heatsink and no FF, will there be a noticeable temperature difference if I touch the motor with my finger? I know this sounds like a weird question, but I don't have any equipment to measure the temperature of my hub motor, so touching it is my only way of measurement.

The ferrofluid is the path to the heat out, so using hubsinks without ferrofluid will have a minimal effect. You don't need to drill a hole in your motor, it is just easier to take out one side (take out 6 screws) adding the ferrofluid, then close. You can benefit of this procedure to take a look at your motor windings, they should not look cooked (enamel very shiny and even).
 
Haha. I don’t know what feral fluid is either. All jokes aside, thank you very much for your replies. I just got the hub sink today, but I guess I will wait until the ferrofluid comes in to install it together. I saw a video of a guy drilling a hole into the hub motor to put “statorade” in so I just assumed that was how all oil installations go as far as hub motors are concerned, my bad. I’m very new to the e-bike scene, so forgive me if I say something unintelligible. Thanks again for the advice!
 
How did you go once you got the FF in there

ive been away so apologies for the late reply but yep, the FF is very important and doubles the effectiveness of the Hubsink alone!



BMXTiger said:
Haha. I don’t know what feral fluid is either. All jokes aside, thank you very much for your replies. I just got the hub sink today, but I guess I will wait until the ferrofluid comes in to install it together. I saw a video of a guy drilling a hole into the hub motor to put “statorade” in so I just assumed that was how all oil installations go as far as hub motors are concerned, my bad. I’m very new to the e-bike scene, so forgive me if I say something unintelligible. Thanks again for the advice!
 
I have a Crystalyte H3525 UFO and a heatsink set. Noting that Grin talk about installing thermal pads to make up the diameter so the heatsink fits, does anyone have a recommendation for the spec of the pads?

Thanks
Tc
 
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