Any evidence of good engineering regarding waterproofing?

[billium]

I've seen lots of talk about new gear design to minimize rattle and improve efficiency but I have not found any official or 3rd party discussion about waterproofing.
I'm not suggesting it is bad but given that it would take a couple of years for issues to surface, it would be nice to know they have done their homework to withstand British winter riding.
Early Brose motors have poor seal engineering and even Bosch motor seals can be improved significantly - see the Ebike motor centre's upgrade kits for details.

It would be nice to know that DJI did it right the first time.

Has anyone done a teardown to see how they keep the water out?

 

[irie]

I've seen lots of talk about new gear design to minimize rattle and improve efficiency but I have not found any official or 3rd party discussion about waterproofing.
I'm not suggesting it is bad but given that it would take a couple of years for issues to surface, it would be nice to know they have done their homework to withstand British winter riding.
Early Brose motors have poor seal engineering and even Bosch motor seals can be improved significantly - see the Ebike motor centre's upgrade kits for details.

It would be nice to know that DJI did it right the first time.

Has anyone done a teardown to see how they keep the water out?

"Any evidence of good engineering regarding waterproofing?"

That ^^^ is quite funny.

 

[Pyr0]

I've not seen any teardown regarding the water resistance, but the m2s motors are ip66 rated.

 

[TheKaiser]

I've not seen any teardown regarding the water resistance, but the m2s motors are ip66 rated.

Yeah, I was going to say the same thing. The difference between the M2S at IP66 and the Bosch CX Gen5 at IP54 seems very relevant to the typical use of a MTB. IP54 can tolerate rain, but not high pressure spray or submersion, whereas IP66 can tolerate both of those.

That all of course assumes that there isn't some little flaw in the M2S waterproofing that only shows up in the real world, but if you put faith in these sorts of industrial ratings then there was definitely more thought put into waterproofing on the M2S

I feel there has been a lack of attention in the industry to this waterproofing issue, so I just want to also call out (in a good way) Gobao which has an IP67 rating on their newer motors, which allows for full submersion in up to 1 meter of water for up to 30min. This is the motor that is being white labeled by several companies including Aventon and a couple smaller European brands.

 

[cream]

Some time passed since the Avinox's birth and I haven't seen/read any case in which the motor was destroyed because of water ingress...guess there aren't so many cases. In any case I don't think anybody can implement a worse waterproofing than Bosch

As for IP66, it won't tolerate jets with pressure higher than 100kPa (3m distance). So forget about washing your bike with high pressure (100bar/10mPa) Carcher style washing devices. No (e)bike motor will survive that.

 

[billium]

Some time passed since the Avinox's birth and I haven't seen/read any case in which the motor was destroyed because of water ingress...guess there aren't so many cases. In any case I don't think anybody can implement a worse waterproofing than Bosch

As for IP66, it won't tolerate jets with pressure higher than 100kPa (3m distance). So forget about washing your bike with high pressure (100bar/10mPa) Carcher style washing devices. No (e)bike motor will survive that.

Motors can be made waterproof for both spray and immersion. Consider your typical electric car - it won't die because it spent a day on a rainy motorway at 70mph or went through a few fords! I don't think it is unreasonable to expect that level of protection from any EMTB motor.

If the design team spent time on this and perhaps used better seal systems then it may have increased the motor price by a pound or two. Question is - did they?

As examples, here are the mitigations to poor original designs made my Ebike motor centre pulled from their upgrade pages.
I suspect similar mods would cost pennies if performed in the factory.

For Brose

• Single lip rotary shaft seal to stop water ingress into the crankshaft needle roller bearing and beyond (This also stops rust damage to the crankshaft bearing surface and premature failure of the crankshaft needle roller bearing)
• Genuine Brose bearing cover seal for the right hand crankshaft ball bearing (Not factory fitted until 2017)
• Waterproof long life grease packed between outer bearings and motor covers. (This helps stop water sitting in these areas and seeping into the outer bearings).
• We also fit an external X-ring seal each side of the crankshaft to further stop the chance of any water ingress into the motor.
• We remove the two ECU cover screws and seal these to stop water ingress into the ECU.
• Finally, we treat and coat the motors’ electric plugs to stop corrosion and water entering the ECU by capillary action along the wires.

For Bosch

• The original torque tube sealing ring is removed and an Oilite self-lubricating bronze bush is fitted to ensure maximum crankshaft support. This stops crankshaft oscillation and aids sealing.
• After the Oilite bush, we fit a single-lip rotary shaft seal, with the lip facing outwards to stop water ingress into the crankshaft and torque tube area. This stops rust damage to the crankshaft bearing surface, premature failure of the crankshaft support bushes, and internal damage to the printed circuit board (PCB) and all other components.
• The left hand crankshaft bearing is replaced with a double-sealed bearing to prevent water ingress into or through this bearing.
• Waterproof long life grease is packed between outer bearings and motor covers. This helps stop water sitting in these areas and seeping into the outer bearings.
• We also remove the PCB and add a silicone coating to the plug assembly gasket seal.
• Silicone gasket sealant is also added to the aluminium motor cover gasket. Water ingress into this area corrodes the gasket faces of the magnesium motor cases.
• Finally, we treat and coat the motors’ electric socket pins to limit corrosion.