IPX ratings resist splash, not immersion, and pressure washers force water into seals and bearings. QERYU sets the line at IPX6 with breathable valves.
A common myth dealers hear is "IPX4 or IPX5 means I can ride in any rain." The IPX rating only means protection against splashes or sprayed water. It does not mean protection against immersion. A mid-drive housing sits low at the bottom bracket, closest to mud and standing water, so its water-ingress risk is higher than a hub motor.
The real killer is the pressure washer. At 80 to 120 bar, a water jet forces liquid through seals that were never meant to hold pressure, through bearing preload gaps, and into cable connectors. Water then collects inside the cavity, causing corrosion, bearing seizure, and even circuit-board short circuits. The damage often appears weeks later, which makes blame hard to assign.
Many "water-damaged motor" failures do not come from rain riding. They come from one wrong wash. Users treat the mid-drive like a car chassis and ignore the precision sensors and electronics inside. Teardowns usually show water in the plug and rust on the bearing, not rain seepage.
For B2B customers, training beats warranty. Give operators a simple illustrated wash guide at handover that forbids spraying the motor and controller directly, and this class of returns drops close to zero. Explaining the risk up front costs far less than arguing after the fact.
QERYU answers with a clear engineering boundary: washable but not pressure-rated. The motor cavity meets IPX6 against strong spray, all exposed connectors use double sealing with a waterproof breathable valve to balance pressure, and the manual forbids directing a pressure washer at the motor. We explain the risk before sale, not after failure.