Latest air cooling mods for ebike hub motor- with drawnings

[ebikedelight]

First I need to apologize for not posting photos of my heatsink cooling mods. When my wife got back from her vacation a few weeks ago, we had a death in the family and had to drive 1200 miles to the east coast and take care of business...and then my wife informed me that she erased my heat sink photos to make room for her vacation photos...

The good news is , Ive spent the last couple weeks, working up what I believe is a even better cooling system then the heat sink mod. It doesnt involve any type of fans or cooling liquid , or heat sinks, but does require a few holes to be drilled into the side hub covers , so it is a bit more involved then just the heat sink mod, but gives noteable cooling effects. As we know, just drilling a dozen holes in the side covers, does allow some cooling, but even then, it is limited because there isnt any outside cooler air, being forced into those cooling holes. I decided to use a " forced air scoop" modification, which uses the rotation of the actual wheel, to force cooler outside air, into a intake vent hole on the sidecover and then have 1 or 2 outlet vent holes to allow the forced air to dissipate heat out of the hub motor. I just completed this modification 2 days ago and got a chance to try it out today, and I am very happy with it. Since much of the heat builds up in the coils , I think its important to have your intake hole/ scoop over as much of the coils as possible, without drilling to close to the outer edge of the hub motor and risking damage/ strength integrity of the hub.

You can use any type of air scoop you wish, and attach it with a high strength silicon to the outside of the hub sidecover, directly above the intake cooling hole. I used the bottom of a square plastic apple juice bottle . I had about 1-1/2" of clearance between my side hub cover and my disc brake...so I made my scoop 1-1/2" tall and its just wide enough to cover the perimeter of the intake hole and its about 3" in length. I made a rough drawing to try and explain this better. If you have any questions, go ahead and ask.

Comparing this mod to the heat sink mod, I can clearly state this mod has better cooling effects. Under the same driving conditions,. my motor was just warm ..with this modification..compared to very warm with the heatsink mod...and very hot, with no mod at all.

Keep in mind, I only did this modification on 1 side of the hub motor...I would imagine doing the exact mod on the other side of the motor, would create even better cooling results.

This modification seems to suggest that it is no longer neccessary to drill 6 -18 holes in both sides of the hub side cover, or hook up external fans....just 2- 4 holes...and using a simple air scoop that uses the rotation of the tire, to force cooler outside air into the hub motor and dissipate heat out thru the exit holes .

Im not sure if someone else has posted this idea before and actually done this modification...im just posting my results.

The height of everyones air scoop, will be different, depending on how much clearance they have between the side cover of their hub motor and their disc brake/ deraulliar.

I apologize for the crappy drawing....the big circle, is the actual ehub...the black dot in the center, is the axle hole.

 

[ebikedelight]

As the wheel rotates, cool air is forced into the open end of the plastic air scoop..and since the back end of the air scoop is closed off, the cooler air is then forced into the inlet cooling hole , over the coils, then the hotter air leaves the hub thru the exit holes....as long as your wheel is rotating , you air forcing cooler air into the ehub...instead of just having a bunch of open holes, where the cooler outside air, will generally flow over the holes, instead of being forced into the holes and into the ehub.