Thorens Td124 Service Manual -

The TD-124 uses an idler wheel to transfer motion from the motor to the platter rim.

The idler wheel must contact both the motor pulley and the inner platter rim with the exact pressure. The manual gives a spring deflection measurement (e.g., “spring eyelet to eyelet length: 22.5mm”). Too much tension grinds the rubber; too little causes slip and wow. thorens td124 service manual