Definitive Tests on the Heating and Cooling of Hub Motors

[sketchism]

Went for a Hillclimb today before and after putting the Hubsinks on one of my bikes for a real world reference
if you're just bored theres some wallabys, a snake and a wheelie in there somewhere too haha

With HubSinks installed sees a temp of 91C at the point the stock motor hit thermal cutoff at 124Cpeak&115 nominal
then at 67c at the bottom of hill with sinks vs 84 stock, on a 25 degree day riding 2km distance and ~400M elevation (average 15% grade)

The difference off-road or in general riding is more pronounced than a constant climb because of the increased rate of cooling between accel spurts

(vid is private because i probably should have used a private road but there wasn't one steep enough)
[youtube]OBuDcXyElvk[/youtube]

Without using ferrofluid yet I noticed my motor just cooling down faster than it was before while stoped and temps slightly lower than before also while running. I got a smaller freewheel and waiting on the tool to remove the one that is on there.....thus my delay.

It will be soon. I was hitting the single tracks pretty hard on Sunday and the bike stayed probably 10 degrees cooler than normal. Most times I'll hit 175 degrees and I was able to hit it three times hard at a peak of 165. The motor still peaks high but drops fast when off the throttle.\

nice nice, im looking forward to your results with FF, i dare say you'll see a dramatic improvement over running them with no FF as well once you have it all dialed in!

 

[Merlin]

pretty sure theres "bombastic" music in the background huh? ;(

 

[sketchism]

pretty sure theres "bombastic" music in the background huh? ;(

wow thats crazy, theres no music at all, literally just me talking and riding

 

[Merlin]

really?

wtf....german GEMA bullshit

vimeo plz

 

[Rix]

Went for a Hillclimb today before and after putting the Hubsinks on one of my bikes for a real world reference
if you're just bored theres some wallabys, a snake and a wheelie in there somewhere too haha

With HubSinks installed sees a temp of 91C at the point the stock motor hit thermal cutoff at 124Cpeak&115 nominal
then at 67c at the bottom of hill with sinks vs 84 stock, on a 25 degree day riding 2km distance and ~400M elevation (average 15% grade)

The difference off-road or in general riding is more pronounced than a constant climb because of the increased rate of cooling between accel spurts

(vid is private because i probably should have used a private road but there wasn't one steep enough)
[youtube]OBuDcXyElvk[/youtube]

Without using ferrofluid yet I noticed my motor just cooling down faster than it was before while stoped and temps slightly lower than before also while running. I got a smaller freewheel and waiting on the tool to remove the one that is on there.....thus my delay.

It will be soon. I was hitting the single tracks pretty hard on Sunday and the bike stayed probably 10 degrees cooler than normal. Most times I'll hit 175 degrees and I was able to hit it three times hard at a peak of 165. The motor still peaks high but drops fast when off the throttle.\

nice nice, im looking forward to your results with FF, i dare say you'll see a dramatic improvement over running them with no FF as well once you have it all dialed in!

This is really impressive Sketch, I have visions of an 8kw H4080 for my next build.

 

[LI-ghtcycle]

Very nice! Thanks for the vid! Did I understand correctly that you're ridding up a 15% grade?! WOW!

Going to have plenty of room in my custom frame for hubsink fins, also good to know that 2 sets of hub sinks fit in the MXUS, I might make that my standard motor as the Cromotor is overkill for the power level I prefer .

 

[Rix]

Very nice! Thanks for the vid! Did I understand correctly that you're ridding up a 15% grade?! WOW!

Going to have plenty of room in my custom frame for hubsink fins, also good to know that 2 sets of hub sinks fit in the MXUS, I might make that my standard motor as the Cromotor is overkill for the power level I prefer .

This is a good point, and now, with these sink fins, we can push more current through smaller and lighter hub motors and don't need to run big motors like before. I find this very appealing as the off road performance and handling aspects will be improved immensely.

 

[Jestronix]

Big question I have is .... will there be side plate hubsinks in production too ? I dare say the side plates should shed a lot of heat too.

 

[macribs]

Jestronix you got oil filled hub, right? Fit one or two of the heat sinks and I think you will be more then happy
I think if you should need more cooling then these heat sinks provide you might wanna look into embedding heat pipes into the heat sinks. That should give you way more cooling capabilities yet you don't need to do anything to you side covers, or even the swing arm which might be the case if doing heat sink for side covers.

 

[sketchism]

This is really impressive Sketch, I have visions of an 8kw H4080 for my next build.

looking forward to it!

also good to know that 2 sets of hub sinks fit in the MXUS, I might make that my standard motor as the Cromotor is overkill for the power level I prefer .

you'll probably find you'll handle the same power level and with the lighter hub with less rotational and unsprung mass penalty

Big question I have is .... will there be side plate hubsinks in production too ? I dare say the side plates should shed a lot of heat too.

we did experiment with them but found that with the disk caliper coming in so close on most hubs on that side and with the chain, derailleur and sprocket on the other, they had to be either so thin (on chain side) or so close to the disk mount that we couldn't get an appreciable surface area without machining the actual sidecovers themselves

Jestronix you got oil filled hub, right? Fit one or two of the heat sinks and I think you will be more then happy
I think if you should need more cooling then these heat sinks provide you might wanna look into embedding heat pipes into the heat sinks. That should give you way more cooling capabilities yet you don't need to do anything to you side covers, or even the swing arm which might be the case if doing heat sink for side covers.

[/quote]

haha i still love the heatpipe idea, the 'Macribs turbo special'

 

[Jestronix]

Yeh I had same issue with side wall heat sinks, clearing the disc brakes etc

 

[burner77]

What is finally the succus of FF? Some lost it somewhere in the motor after a while and is superb when newly added…
And does a MXUS V3 Turbo has to be sealed when adding it?
We all are looking desperately what could be the best especially in mountain areas, like me. Pushing a DD up to the mountain makes me happy only for 500 height meters or less.
As I can see a combo of FF, Hubsink, maybe black paint. If hole venting is not a option because of too much dirt and water.
I know it is all said in the hundreds of threads, but less long therm and always something new. Could me make a status line and say what could be done with actual science and hardware. Thanks

 

[Merlin]

My FF sweeped a bit out. So i have to seal it and think all have to seal if they run higher speeds.
on Normal speeds everything is ok.


Big Hubbie with FF + Hubsinks is at now the non plus ultra in heat shredding.
FF for itself is a huge improvement as you can see in justins trip simulator.

 

[litespeed]

So I finally got off my ass and installed my ferrofluid. Thanks Samd! Stuff is wild going in. As close as I can guesstimate I put 10 to 12ml in. Unfortunately I have a wicked sinus infection so testing will have to wait till later in the week or next weekend. That part sucks!

Tom

 

[Samd]

Thanks litespeed.

I am reading that some people want to try it on gearmotors. Hubsinks too.

I cannot work on gearmotors in the same way. Nor hubsinks.


Sent from my iPhone using Tapatalk

 

[MrDude_1]

Thanks litespeed.

I am reading that some people want to try it on gearmotors. Hubsinks too.

I cannot work on gearmotors in the same way. Nor hubsinks.


Sent from my iPhone using Tapatalk

however on hub motors, you can still do the ATF fill... that will carry the heat from the motor to the case.

 

[madin88]

And does a MXUS V3 Turbo has to be sealed when adding it?

My FF sweeped a bit out. So i have to seal it and think all have to seal if they run higher speeds.
on Normal speeds everything is ok.

i personally seal up all of my hub motors, no matter if FF is used or not.
just think if you're getting unexpected caught in a shower of rain :wink:
installing a pressure valve would make things perfect.

Most manufacturer install sealed bearings on theire motors together with additional sealing rings (mxus), but for the sidecovers they don't care (which i guess is because they want to sell a new motor to you every few years).

 

[fechter]

I had to add about 11cc of ferrofluid to my A2B Metro motor before I started seeing a slight increase in the no-load current. I stopped when it reached about 4W worth of drag at full speed.

I definitely see faster cooling when I stop and it takes longer to get hot in the first place. The A2B motor has a somewhat unique design in that there are no side covers. The shell is just two pieces press fitted onto the magnet ring. Sucks to take apart and service, but not many places for stuff to leak out. The axle is not totally sealed, so functions as the vent. So far I have not seen any signs of leakage.

 

[Merlin]

Maddin how do ou seal your hubs?
i had some tries with silicon but my sideplates after that are not "plan" and the disc wobbles more then the "normal" 1mm.
thats PITA to make the disc not rubbing the brakepads and i hate that -tsh-tsh-tsh-tsh- sounds


and fechter, i had also no problems on normal speed.
but everything above ~100kph for longer times makes "spots" on my rim.

 

[John Bozi]

2 x QS hub motors around 15kw & 1 x 1.5kw @ 3kw = 3 sets of sinks resulting in 3 x zero heat stopping

It's hard not during the ride for the Hub boys to pass familiar points and comment on what temperature they were last time at a particular place and how it is now not a issue worth thinking about anymore.

Shame the main camera man at the front on a mid drive couldn't stay on the trail long enough :lol:

No fins were harmed in the making of this video. A lot of heat was shed.

[youtube]1kykW4p6D4c[/youtube]

 

[litespeed]

LOL looks like someone needs some new tires.

Great video and I envy have buddies to ride with on those great trails. Looks awesome.

Tom

 

[drew12345]

I got my hubsinks! Hope to install within couple days. Thanks Sketch.

 

[Brake]

Got mine too. Thank you, thank you!

 

[Rix]

LOL looks like someone needs some new tires.

Great video and I envy have buddies to ride with on those great trails. Looks awesome.

Tom

+1

 

[macribs]

Ok so we have seen ICE engines that will do several 100 000 km before they start leaking oil. And for most of the ICe motors the end of the crankshaft penetrates the engine. Yet most manufacturers manage to keep that crankshaft sealed for several 100 000 of km.

The oil cooling should be possible without leakage for hubmotors as well. Could there be machined a trace/track/groove for an O ring to seal the side covers? What about the axle? IS there any other options then the Inpro/Seal Bearing Isolator? This does seems to work, but hard to get hold of at decent price.

Could O rings possible do the trick? Or some kind of automotive shaft seals? It makes no sense to me that we are not able to seal the hub motor, like the automotive industry has done for several decades without problems.