If the pedals move with difficulty, inspect the working surfaces of the pedals, bushings and axle. If shallow scratches or traces of oxidation are found on the surfaces of metal parts, they are sanded with sandpaper of grain size from 10 to M40. Non-metallic parts are replaced with new ones at each disassembly.
The elasticity of the springs is checked by their length (in mm - right column) under a certain load (in kgf - left column), using the data below:
The original source is published on the website VazBook