Sidurit

Sidurit is the Estonian term for the clutch, a mechanical device that connects and disconnects the engine from the drivetrain to enable smooth gear changes and to prevent stalling when starting from a stop. In most cars with manual transmissions, the sidur is a friction clutch consisting of a clutch disc, a pressure plate, and a flywheel. The pedal actuates a release mechanism—via cable, hydraulic, or electronic linkage—that disengages the clutch by separating the disc from the flywheel, interrupting torque transmission. When the clutch is engaged, engine torque is transmitted to the transmission and drive wheels.

There are several designs associated with sidurid. A standard dry friction clutch is common in many manual transmissions. Modern vehicles may use hydraulic or electric actuation, and some automatics employ multiple wet clutches within the transmission or dual-clutch systems that preselect gears and are managed by a computer. Centrifugal clutches are used in certain motorcycles, go-karts, and small power tools.

Wear and maintenance: Clutch wear results from repetitive engagement and disconnection, thinning the clutch disc and reducing torque transfer efficiency. Symptoms include slipping under load, a high or inconsistent bite point, burning smell, or noises during gear changes. Replacement typically involves the clutch disc, pressure plate, and release bearing, and sometimes resurfacing or replacing the flywheel. Life expectancy varies widely, often tens of thousands of kilometers, depending on driving style, vehicle type, and clutch design. Hydraulic systems require checking and occasional fluid replacement.

Applications: Beyond automobiles, sidurid are used in motorcycles, industrial machinery, and other power transmission systems where torque transfer must be controllable.