1. 63 Tiger Cub - Clutch Will, Adam, Robert, and Jack

2. What is a clutch? A clutch is a device used in machines to transmit power from the engine to the transmission It can be engaged to allow the engine and transmission to spin at the same speed or disengaged to allow them to spin at different speeds (thus allowing the rider to shift gears) Wet vs. dry clutch?

3. Why do we need a clutch? The clutch allows for a smoother shift from gear to gear Without a clutch the transmission would wear down over time Without a clutch, the only way to stop the wheels from spinning would be to turn off the engine (because otherwise whenever the engine spins the wheels would too)

4. Clutch Parts

6. Backing Plate Backing plate, rebound rubber, drive rubber, spider, lock washer, centre, centre driving cup, backing plate pin, sprocket bearing ball, sprocket bearing ring

7. Sprocket and Housing Double sprockets

8. Driven Plates Steel Lugs on inside Engage with the engine

9. Driving Plates Pads = cork Lugs on outside Engage with the transmission

10. Pressure Plate Presses plates together to engage clutch Pushed up by clutch operating rod to disengage clutch and allow rider to shift

11. Spring Cups

12. Pressure Springs Press on pressure plate to engage clutch

13. Pressure Spring Nuts

14. Sprocket and Primary Chain Why double chain? – Innovation  double chain is more durable, single chain caused the sprockets to wear down/break

15. Clutch Lever

16. Clutch Cable

17. Clutch Operating Rod

18. How It Works When the clutch is engaged, the driven and driving plates are pressed together by the pressure plate and springs and spin at the same speed When the clutch lever is pulled, the clutch operating rod pushes up on the pressure plate, disengaging the clutch and allowing the engine and transmission to spin at different speeds, thus allowing the rider to shift gears

19. Friction - Why multiple plates? Having multiple plates increases the friction, thus reducing the slippage The greater the friction, the greater the torque that the clutch can handle without slipping

20. How much force is applied by the springs? Gear ratio: 19/48 Length of spring: 1.53 in. =.1275 ft. Length of spring after 20 lbs. applied = 1.324 in. =.1103 ft. # of surfaces touching = 7 Coefficient of friction = 0.8 (cork on steel) Diameter of clutch = 5.33 in. =.444 ft. Clutch slips @ 50 ft.lbs.

21. How much force is applied by the springs? F = kx (spring) F = uN (friction) T = rF (torque) Given a torque, we found compression in the springs If we assume a certain amount of compression in the spring, we can find any torque