Long vibration wears bearings and loosens screws; shock breaks gear teeth and cracks plastic. QERYU answers with sealed bearings, steel gears, and locking.
A mid-drive sits right at the bottom bracket and takes pedaling shocks and road vibration directly. Long-term high-frequency vibration slowly wears bearing races and loosens controller plugs and mounting screws, causing intermittent contact faults. This placement is the price of putting the drive at the core of the bike.
Worse are shock loads. Hitting a curb, a drop, or a hard start from standstill creates brief peak stress on gears and plastic parts. Light cases show cracked housings; severe cases show broken gear teeth. Such damage often falls outside the "normal use" definition in a standard warranty.
Dealers often misread this as an electronic fault. A diagnostic tool finds no clear code, yet noise and lost assist keep returning. The symptom looks electronic; the cause is metal fatigue.
For B2B customers, fleets should keep a vibration duty log. High-impact routes for delivery, off-road, and shared bikes need shorter inspection intervals and recorded screw torque, so mechanical fatigue becomes scheduled maintenance rather than a surprise claim.
QERYU puts mechanics before electronics. We use sealed deep-groove ball bearings with preload, powder-metal steel gears to resist impact, and ribbed plastic shells validated by drop simulation. All screws use thread-locking compound and torque marks, so vibration and shock damage is minimized at the design stage.