The Purpose of the Clutch

• Your dirt bike's clutch is responsible for controlling the transfer of power generated by the engine to transmission, allowing the rear wheel to move the motorcycle forward. With the clutch lever pulled in, the plates within the clutch disengage, allowing the engine's output shaft to spin freely without turning the transmission. While the clutch is disengaged, the transmission gears are released from the constant load placed by the engine. This allows the dirt bike's rider to shift through the gears without causing stress that will eventually wear away the gears' teeth. Once the lever is release, the clutch plates engage and the transmission resumes operation.
  
  

Shifting with the Clutch

• Shifting your dirt bike under normal riding situations should always be performed with the clutch lever. This is especially important when traveling at slower speeds, as the clutch provides fine control over the motorcycle's power output, allowing you to control exact how fast you are traveling over rough terrain. Likewise, using the clutch reduces the risk of damaging the gears and shifter forks within the transmission while shifting at higher speeds. Simply selecting a gear without the use of the clutch -- and proper technique -- will force the gears to change while they are still under a load. In worse case scenarios, this can break teeth off of the gears, which will cause collateral damage if the fragments are caught within the transmission.
  
  

The Purpose of Clutchless Shifting

• Shifting without the use of a clutch can be beneficial in off-road racing, allowing the rider to move through the gears without taking the to pull in the clutch, select a gear then release the clutch. These few seconds are meaningless on a trail ride, but can mean the difference between winning or losing to a racer. Shifting into a higher gear without the clutch, especially during the first few seconds of a race, can give a racer enough of a head start to make it into the critical first turn. Likewise, downshifting can allow the rear wheel to spin faster and slide as you approach a turn. While this is normally not desired on the trail, sliding into a turn maintains the dirt bike's speed and points the motorcycle toward the turn's exit point.
  
  

Practice and Technique

• Learning to safely and effectively shift without the clutch takes practice. Start by accelerating in a straight line in first gear. Load the shift lever by gently pressing up on the lever with the tip of your boot until you feel slight resistance. Slightly roll the throttle grip back to partially close the throttle. The shift lever will move upward easily and shift into second gear as the transmission unloads. Open the throttle immediately to accelerate, then repeat as needed until you have upshifted through your dirt bike's gears. Downshifting into a lower gear is done in similar, but reversed, manner. Load the lever by pushing down lightly. Close the throttle to decelerate, then quickly blip -- momentarily open -- the throttle. The shifter lever will move downward as the engine speed increases. Further downshifts can be performed in this manner.