Ebike Hub Motor overheating cooling solution - HUBSINK OFFICIAL THREAD


100 W
Feb 17, 2016
GC, Australia
Hey guys! With over a year of Real Life™, Computational and Wind Tunnel testing and a couple of race wins now under our belts, i figured i should actually declare them out of BETA testing and make a sales thread for the HubSinks, im super humbled by the help i've received from everyone during the beta stages and for everyone whos running them on their bikes so far, hopefully i've helped contribute a little to a community that's given me so much fun!

I'll keep this thread simple as all the information you can ever need is in the '"Definitive Tests on the Heating and Cooling of Hub Motors" thread (link below) and i would love to invite people running the HubSinks to share pics of their rides in the thread also!
For ES members i have included a discount code, enter ENDLESS in the checkout to receive a discount off the purchase or click this link - https://hubsink.com/discount/ENDLESS

In short, the HubSinks have been proven to vastly improve the thermal management and power handling of hub motors allowing much higher power levels and/or endurance to be achieved with higher motor efficiency due to lower copper losses, especially when combined with Grin's Statorade.


if your hub motor is overheating or thermal limiting, or you are planning on running substantially more power than stock the first thing you need to do is install Sinks and FF, detailed information on their performance can be found here - http://www.hubsink.com and here https://dl.dropboxusercontent.com/c...3l5vYdfKtiLegkWbVBMLPD66vMyOVJfFhP6YjWan/file

Some vids here of the HubSinks in action
HubSink Test and installation

TT1500 race video with HubSinks installed


You can follow the HubSink development and testing on the forum here, warning its a long read- https://endless-sphere.com/forums/viewtopic.php?f=2&t=48753&start=1550

For ES members i have included a discount code, enter ENDLESS in the checkout to receive a discount off the purchase or click this link - https://hubsink.com/discount/ENDLESS


Andy Braidford - It took 10 minutes to install, and well the information speaks for itself. Looks good, easy install, better heat shedding.. what more do you want. Cheers guys!


"The HubSinks work well, and they look great, too. When the late
spring/summer season comes around I'll be able to test their
effectiveness under hotter conditions."

Dr Bass

Quokka -
Just gave my bike an absolute hiding. Now running ff and hubsinks. Adaptto on boost with ovs 3 at 120amps. Temp here is mid 30's and i tackled the same route i did in my first test with just hubsinks. Air temp is around 10 degrees cooler. The motor temp stayed cool... really really cool. Was running about 30 degrees cooler on the same hills, but was going faster. Not only does the motor run cooler but the motor seems much more powerful at lower temps?? It feels like an absolute animal now. Does anyone know if torque goes down as motor temp goes up? I then went in search of something harder in the national park. The absolute hottest i could get was 90 in bush. That was going up a dirt road, up a big hill- maybe 2km long, full throttle. I just couldnt get it up to the same temps as it used to run pre- ff and hubsinks. Along the single tracks i couldnt go that fast because of all the turns, front wheel spent alot of time in the air, its a real blast to ride, in these parts it was down in the 60's Final heat test I did was a simple brute speed run. Max power, over 100 for a nice long flat stretch for around 7-8km. Peak temp 95. All up i did around 80km of testing mostly on dirt and nearly had a few big stacks :shock: hitting soft powdery sand at high speed really speeds up ones heart rate. Only way i see that i could hit the temp cut out would be a really steep hill (actually i mean a mountain) at full throttle. There is nothing like that here so i am done :D Bottom line, i think it lowered the temps by at least 20deg c. Probably more


Hugh pomeroy - The Hub Sink Is A great invention,It works very well on my Bikes.I took My 7500 watt Fat Bike Up The mountain, Full speed My motor Was Not Warm at all.The Hub Sink Took All The Heat out Of My motor.
Bottom Line Is That It works .


Jesse Haubner - Hubs are making a difference on the fire trails, on a couple hills I used to have to pull over and allow it to cool down, now I get to the top :)
Running 8kw into the mxus ,


Thanks to Sketch now my ass hurts more.......hmmm....that sounded bad! What I mean is now I ride longer which makes my but hurt since my motor isn't always trying to kill it self heating up so much. After Hubsinks and ferrofluid I've now tested my battery capacity in one non-stop ride.....never had before. Always had to stop for a cool down session. I actually now feel like I need a bigger pack.....dam you Sketch! Thanks for turning my rides into tours and putting my heating anxieties to rest.

You have done more than your fair share contributing to this community. Excellent work but no time to slouch now....what's next?

I appreciate all that you did for me.



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While I did not perform a specific HubSinks test, I did write-up my experience testing the Edge1500 direct-drive motor (35mm stator) in three configurations: (1) without any modifications, (2) with the addition of Statorade, and (3) with the further addition of Hubsinks. As most have discovered the addition of Hubsinks to a direct-drive motor using some sort of fluid cooling (Statorade or oil), noticeably increases the motor's heat-shedding ability and improves the system's usability by avoiding overheating events and the consequent down-time.

+1 for Hubsinks being awesome. These combined with Statorade on my QS 205 on the street has banished even the thought of heat issues. My ass or battery capacity (who would have thought 2.5kwh wasn't enough a few years ago!) is now the limiting factor. Thanks for the huge community contribution Sketch - you're a certified 'A' grade GC.
To anyone looking for high power but worry about heat the combination of Sketch's hubsinks with FF is sure to solve that problem. My bike running a QS 205 & Sabvoton combo on 20s at 150a battery came alive after this upgrade. Previously when riding hard my motor temperature would often approach 100 degrees Celsius. After this quick installation I could drain my whole pack (2kwh) as fast as I wanted without having to worry about the heat. In general my temps while riding were about 15-20C cooler but also cooled down much quicker when going easy or stopped. Also with less heat I noticed an increase in range as I was wasting less power. Acceleration and torque also remained much the same throughout the ride as opposed to previously decreasing as the motor temp increased. Overall I can't recommend the hubsinks enough, thanks Sketch!


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Well as the motor heats up soon wires will too. And before you know it your now heated motor and wires got increased resistance meaning efficiencies will drop, hence the less snappiness, and less torque acceleration.

I've thought of this most like an academic exercise, where losses are small enough to be measured but not big enough to really matter.

I am sure some of the EE's here can do a quick back of the napkin calculation to quantify the losses or maybe a guesstimate?

As soon as heat build up starts to increase efficiencies losses could potentially excel. Because as efficiencies level drops, you will twist throttle more to compensate. In this state heat will.generate more heat will.generate spike in resistance will make even more heat.

3am not sure I am making any sense

Sent from my LG-D855 using Tapatalk
Im running a Max-E with 9.6kW peak at the moment, soon going to upgrade that battery to 18kW and I really have to admit that the hubsinks worked on me really good so far. You can count from 10-0 when the motor has achieved 100°C and it will be down at 90°C again with that mod with 8ml ff, like I have. I also run a QS 205 V3 extra motor from Vector and it really cools down like nothing. Im happy with it.

Best regards,

djcornock said:
Thanks hubsink!!!

hahahahah no way you have installed that controller up there.. What a great idea actually :D :mrgreen: :mrgreen:
trying to work out whether hubsink will work on a magic pie v1 hub motor. (thus most magic pies)

I have my doubt due to the width between the flange faces and the ring diameter. Anyway golden motor.ru was good for the tech spec drawings. I think its fairly easy to estimate the measurements as I reckon there diagrams are to scale.

I was thinking on the website, where you are selling the hubsink (websites) you should have both a known to fit list and a known don't fit list.

Also if they don't fit are you going to make more variants for smaller hubs and thinner ones?

I think I am just going to have to roll my own using small heatsinks and a bit of craftiness but I do like the product.
The next step up in hub motor efficiency, is to have manufacturers mold their hub motor shells, so they have these cooling fins/ heat sinks as part of the hub motor . Not having to use thermal glue and having the heat sink as a complete part of the hub shell, should only make it more efficient at shedding heat. Wonder what manufacturer will be the first to
offer such a setup ?
As noted in your thread where you say teh same thing:

The best thing is not to produce the heat in the first place.

Any heat you make is wasted energy.

If you pick the right motor (winding and size) for the job, in the right size wheel, with the right controller and battery, and heat won't be a problem.

Whenever you have a motor that gets so hot that it needs extra cooling, it's being run beyond it's design, and it's the wrong motor/controller/battery for the job.

It doesn't mean that you can't use them anyway, and just add extra cooling, but it's not more efficient to do that--it's still less efficient than using the right parts to start with.
rumme said:
The next step up in hub motor efficiency, is to have manufacturers mold their hub motor shells, so they have these cooling fins/ heat sinks as part of the hub motor . Not having to use thermal glue and having the heat sink as a complete part of the hub shell, should only make it more efficient at shedding heat. Wonder what manufacturer will be the first to
offer such a setup ?

Well no actually. Steel will "hold onto" the heat longer then aluminium will. So even if there is no thermal paste bridge if the hubsink is an integrated part of the hub motor design I am pretty sure the net result will be better with a larger size aluminium heatsink. Not to mention the amount of steel used for the outer shell should be no greater then what is actually needed for magnets and strength.

Keep the amount of used steel to a minimum within reason and add aluminum fins to take care of cooling. Good for efficient heat exchange and good for the overall weight of the hub motor.
John Bozi said:
Been rocking these on a couple of bikes now.

Thumbs up!


Iirc you used to ride a dual motor(hub+midmotor) to cope with the long and harsh climbs you ride in your "backyard". Before heatsink and FF hub motor was not possible for you so you added a mid drive as well. Now you can ride the same trails with just your hub motor as the heatsink and FF now can deal with the heat?

People watch some of JohnB's older videos, like a year or two ago, you will be amazed what kind of harshness he needs to tackle.
Hey Macribs,

I'll keep this short ish. The FF Sinks solution with a large hub 8t in 17" wheel is great, but you can't expect something that is in the wrong gear still to be as effective at slow steep climbing as a mid drive in the right gear. No hub motor with any mods can never do what my mid drive could do. My big block was geared to like 25kmh at one stage and I could climb endlessly until there would be a mid drive fail.... (every second ride)

Having said that Since I started riding the hub I have only had one issue with hall wires cut by my disc rotors and swapped it to the other set.... Since then I have never done anything to the bike, not even lubed my chain. I just sit on it and ride everywhere without heat problems on about 90% of riding.

I highly doubt even 1 % of riders ever dream of tackling the stuff I would overheat on in that 10% I still overheat. I like to stop a couple of times on a 40 kmh mountain hike anyway and have a cold beer in the back pack :)

The main thing is that this solution beats putting holes in your hub. No dissasembling and no intrusion of matter. It also beats other solutions for me because I could not be bothered with opening this thing and trying things like fans or sealing large amounts of oil.

Hubsinks with ff are the best solution for a hub motor and worth every cent for those reasons.

Merlin said:
...from the beginning.
best cooling solution ever =)


damn that looks nice!
Hi, i just made an order. How long (roughly) will the package take to get to the U.K?
hey Andrew your order went out in todays (monday morning) post so say 7 days to be safe