Water sealing on hubs and mid-drives....

[Electro-Fox]

A question that has been nagging me is concerning the water resistance of hub motors and mid-drives. I am not suggesting the type of submersion, where the drive or hub is completely submerged, at least not for a long time, but more like riding through a flooded street. In respect to a hub, I know that if you have a 29er vs a 20 inch wheel that obviously the 29er would be farther away from a complete submersion. I look at the mid drives such as the Bosch and those are more to bottom bracket height as opposed to a hub, and wheel size.
So just how resistant to damage from riding through deeper water are they? The Bosch looks like it is really sealed well, where hub motors seem like they would be more prone to water getting in. I know connections are another part of this too, but it seems that shrink wrap would help with that. So can they take a submersion at all, for a short amount of time? I think that you could do a wrap like 3m makes (the car wrap materials) and cover the hub before lacing, which would help prevent water from entering through the cover. Of course if you ever had to remove the cover, you would have to redo the wrap.

Any thoughts?

EF

 

[MadRhino]

Water inside electric motors is not much of a problem, as long as you don't let it freeze. :wink:

Salt water though, is not that good.

 

[amberwolf]

Since you'd have to poke a few dozen holes in the shrinkwrap to lace it up, it wouldnt' be sealed anymore after you lace it.

But the real problem is that water getting in is going to happen no matter what you do (look up Justin's youtube videos about that; if you odn't find them on ES then look on the Grin Tech site's blog).

So if you seal it up you're sealing anything that does get in there inside, where it will continue to act on the metals.

What you would want to do is vent it with drains, and perhaps coat it's insides with a sealant. See the recent thread from Doctorbass about that (or the various other such threads about sealing motors or water in motors).

 

[motomech]

Unless the water gets up over the brg.s, not much gets in, even if it is splashing about the brg. area.
Eventually, it will drain and evaporate(w/ motor heat help). The water leaves, but grit and other contaminates remain.
If you ride in wet conditions much, it is a good idea to take it apart and clean it w/ contact/brake cleaner @ the end of the rainy season.
(since you haven't bothered to fill out your profile, we don't know where you are at. If you live, say Seattle, clean the motor at least twice a year).

 

[Jestronix]

I run trans oil, I siliconed the gaps to seal it, I have one breather filler hole near the axle. Having oil will keep water at bay and the breather hole should keep the small Lunt of water that may get in a place the escape, especially when I get the motor yo near 100c

 

[Electro-Fox]

It puzzles me that there are electric trolling motors than run in the water constantly with no problems but bicycle hub motors can't. Obviously the level of product quality is not the same.

 

[Sunder]

It puzzles me that there are electric trolling motors than run in the water constantly with no problems but bicycle hub motors can't. Obviously the level of product quality is not the same.

And I'm surprised my Oneida fork still looks great after 9 years despite near daily immersion in water, but my Bunnings gardening fork has rusted away.

Wait, what? You design for purpose. Trolling motors are designed for use near water. Electric bikes are not.

And that's not even taking into account everyone's feedback above, that water ingestion is generally not a huge problem for electric bike motors. It's not like they stop or electrocute you as soon as it starts getting a bit misty - You basically have to use it as a submarine to cause immediate problems. Even flooded street just requires some maintenance afterwards.

To be absolutely frank, I'd rather than a hub motor ebike through 50cm of water, than a car. And for the difference of 10s of thousands of dollars, THERE is where you would expect something to be more waterproof.

 

[ddk]

interesting
I live in an area that gets more rain than Seattle, by the ocean and have never cleaned or dried my hub motors, now 4-5 years old with many, many miles or kilometers ridden in the wet.
...just saying.

 

[Electro-Fox]

interesting
I live in an area that gets more rain than Seattle, by the ocean and have never cleaned or dried my hub motors, now 4-5 years old with many, many miles or kilometers ridden in the wet.
...just saying.

What motors are you using...oh, thanks for the comment.

 

[Electro-Fox]

[/quote].... You design for purpose. Trolling motors are designed for use near water. Electric bikes are not. [/quote]

Yeah...it was more an observation. I always want what is not available. But that said, if a hub motor was at that level of construction it would be cool. However, it would probably be a bitch to open up.

 

[ddk]

inter....

What motors are you using...oh, thanks for the comment.

Mxus geared-hub on the exposed front wheel of the trike (pictured)
unknown driving the same trike's rear differential but it's well-protected from any wash

Magic Pie II on the front of my un-pictured trike
Bafang geared-hub (older model) driving the input to a NuVinci transmission driving one rear wheel

Aotema DD driving the front wheel (x2) (these trikes are not mine, but have been on the road for 6 and 3 years respectively... I've lost track of the others I've built but assume they still work since they use similar components)

...as you might tell, it matters not who manufactured the motor but I did have one motor freeze its' bearings after the user left his bike exposed outside all winter (rainy season)