Motorcycle drive chain tensioner - has jockey pulley tensioned to chain by pull rod fixed to main frame

摘要

The rear wheel is carried by a swinging fork (4) sprung (5) to the motor cycle frame (1). The wheel is driven via a chain (7), kept at a constant tension by a tensioning roller (14). The roller is carried by an arm (9) pivoted to the rear wheel swinging arm on a pin. The tensioning arm is supported by a pull rod (12) whose free end is attached to a main frame bolt (13) by a serration to give an optimal chain tension at all rear wheel movements. The roller can be of metal or a suitable plastic and sprung in relation to the chain tensioner.