Bottom-bracket torque sits around 25 to 35 N·m; too tight adds resistance and heat, too loose creaks. QERYU marks the window and ships a calibrated wrench.
A mid-drive is fixed to the frame through the bottom bracket, and install torque directly shapes long-term behavior. The industry experience range is about 25 to 35 N·m. Set it wrong and the symptom shows up months later.
Over-tightening transfers extra stress to the frame and bearings, adds rotation resistance, and causes local overheating shown as heavy pedaling and unexplained range loss. Under-tightening lets the motor shift slightly against pedal reaction, creating creaks and accelerating wear on threads and locating faces.
Creaks are the complaint dealers hear most and define least, often blamed on "build quality" and hurting brand trust. It is acoustic, intermittent, and easy to misattribute.
For B2B customers, assembly belongs on the process card: use a calibrated torque wrench, record the value per unit, and inspect the bottom-bracket shell at incoming. Turning the 25 to 35 N·m tolerance into an auditable step removes a large share of creak returns.
QERYU answers with "assembled right, it stays quiet." We mark the recommended torque window on the housing with a locating pin, ship a calibrated wrench and install guide, and use a thickened bottom-bracket cup with an anti-fretting coating on the frame side, turning the 25 to 35 N·m tolerance into a repeatable process.