[Tommy]

If you know how far the clutch fork must travel to disengage the clutch, and you know how far the master cylinder rod moves when you depress the clutch, you can calculate what size master cylinder and slave cylinder you need. The basic relationship is that the slave cylinder rod travel times the square of the slave cylinder diameter equals the master cylinder rod travel times the square of the master cylinder diameter. For example, for every inch a 7/8" diameter master cylinder rod travels, a 3/4" slave cylinder rod will travel 1.36" So, if your clutch pedal moves the master cylinder rod 2" at full travel, the slave cylinder will move the clutch fork almost 2 3/4".