4 ms·

There is a simple scale for water and dirt ingress, e.g. IP65 for protection from water jets and fine dust: https://www.iec.ch/ip-ratings https://www.iec.ch/ip

There is a simple scale for water and dirt ingress, e.g. IP65 for protection from water jets and fine dust: https://www.iec.ch/ip-ratings https://www.iec.ch/ip-ratings There are labs that test equipment and verify the claimed ratings. It should be simple for the bike or motor manufacturers to upgrade their seals by one IP step. Most suppliers provide a significant range of IP coverage in their catalogs. The price difference is probably small. The only issue is that any maintenance on the motors has to respect the seals - understand how to disassemble and reassemble without compromising the join.

londons_explore 2y ago
Most ebike motors are air cooled - ie. Outdoor air goes into the motor and flows around the magnets and coils to cool them. Such a design is fundamentally incompatible with being fully water sealed.
- zarzavat 2y ago
  I feel like there must be some clever solution to this using heat sinks / heat pipes.
  - londons_explore 2y ago
    There is, but weight, cost, etc. BLDC motor design also has a conundrum - most of the heat is made in the motor coils, and they can be designed to get up to about 250C, which makes them easy to cool. However, they are wrapped round thermally conductive steel touching thermally sensitive neodymium magnets which have to stay below ~60C for full performance. So it isn't simply a matter of getting rid of heat - it's a game of preventing heat transfer.
    - InSteady 2y ago
      Weight really isn't such an issue with ebikes. I'm riding around a 62lb clunker, carry a 10lb chain lock everywhere, plus I'm hauling big loads of groceries and other crap. Even an extra 5lbs isn't going to make a big difference, nor would an extra $150 to the purchase price if it means years of added longevity. The engineering challenges make sense. Hopefully it is something that is being actively R&D'd.
- HeatrayEnjoyer 2y ago
  There's no combustion, why is there cooling at all?
  - inglor_cz 2y ago
    Friction of internal components of the motor -> heat.
    - londons_explore 2y ago
      It's mostly heating due to the resistance of the motor coils and magnetic hysteresis of the steel core. Friction is a small part.
  - isbvhodnvemrwvn 2y ago
    There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either.
    - HeatrayEnjoyer 2y ago
      > There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either. A kettle sits on top of a flame... which is combustion. Axles should not be getting hot. You want to get your car checked. Brakes are intentionally designed to cause as much friction as possible, the opposite of an electric rotor.

londons_explore 2y ago

Most ebike motors are air cooled - ie. Outdoor air goes into the motor and flows around the magnets and coils to cool them. Such a design is fundamentally incompatible with being fully water sealed.

zarzavat 2y ago
I feel like there must be some clever solution to this using heat sinks / heat pipes.
- londons_explore 2y ago
  There is, but weight, cost, etc. BLDC motor design also has a conundrum - most of the heat is made in the motor coils, and they can be designed to get up to about 250C, which makes them easy to cool. However, they are wrapped round thermally conductive steel touching thermally sensitive neodymium magnets which have to stay below ~60C for full performance. So it isn't simply a matter of getting rid of heat - it's a game of preventing heat transfer.
  - InSteady 2y ago
    Weight really isn't such an issue with ebikes. I'm riding around a 62lb clunker, carry a 10lb chain lock everywhere, plus I'm hauling big loads of groceries and other crap. Even an extra 5lbs isn't going to make a big difference, nor would an extra $150 to the purchase price if it means years of added longevity. The engineering challenges make sense. Hopefully it is something that is being actively R&D'd.
HeatrayEnjoyer 2y ago
There's no combustion, why is there cooling at all?
- inglor_cz 2y ago
  Friction of internal components of the motor -> heat.
  - londons_explore 2y ago
    It's mostly heating due to the resistance of the motor coils and magnetic hysteresis of the steel core. Friction is a small part.
- isbvhodnvemrwvn 2y ago
  There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either.
  - HeatrayEnjoyer 2y ago
    > There is no combustion in a kettle either, why does it boil water? Axles and brakes don't combust either. A kettle sits on top of a flame... which is combustion. Axles should not be getting hot. You want to get your car checked. Brakes are intentionally designed to cause as much friction as possible, the opposite of an electric rotor.