[ Ссылка ]

The ingenious “semi-automatic” clutch makes riding simple – or challenging for experienced bikers! Unlike scooters with variable-speed, direct drive transmissions, these small 125cc motorcycles utilize a multi-gear transmission, operated by foot lever and a semi-automatic clutch.

The “semi-automatic clutch” is STILL a clutch. The motorcycle transmission is shifting between separate gears. The “semi-automatic clutch” only makes this process easier – at least for the inexperienced rider. But experienced motorcycle riders need to unlearn their shifting habits.

Instead of the “1-down, 4 (or 5) up” pattern common to conventional motorcycle gear boxes, this transmission uses a straight 1-2-3-4 down shift pattern. From neutral, first gear is one click down on the toe lever, followed by 2nd, 3rd, and 4th gears. Then, using the heel-toe shift lever, down-shifting from 4th gear down to 1st is accomplished by four clicks DOWN with your heel.

With a conventional clutch, you release the clutch lever slowly as you open the throttle to engage first gear. Every motorcycle rider learns how to apply the right amount of throttle to avoid stalling the engine – or too much throttle and popping a wheelie! In contrast, the semi-automatic clutch is controlled by the foot lever.

From a standing stop with the transmission in neutral, you simply down click into first gear. The engine will happily idle and will NOT stall! When you are ready to ride, you add throttle, and the gears engage to drive the chain and propel the bike forward. As you gain speed, back off the throttle, then click down to the next gear. The semi-automatic clutch smoothly engages each gear in succession. Similar to a manual clutch in a car or other motorcycles, you only need to reduce the throttle momentarily to allow the higher gears to smoothly engage.

The semi-automatic clutch requires a slightly different shifting method as you DOWNSHIFT through the gears. With a standard hand clutch, the rider downshifts by releasing the clutch lever while simultaneously “blipping” the throttle. As the motorcycle slows, you need to ADD throttle to match the engine RPMs with the lower gears. Again, this process is fast and mostly unconscious for the experienced rider.

New riders often have trouble downshifting the semi-automatic clutch. As they slow down, they heavily stomp on the heel lever and force the transmission into the lower gear. But the engine is revving too slow for that lower gear, so the rear tire skids momentarily and the cycle jerks until the engine catches up to the wheel speed. When riding with a semi-automatic clutch, remember to “blip” the throttle slightly to increase engine RPMs as you downshift. Click down with your heel to the next lower gear and slowly release the shift lever. You have just duplicated the process of downshifting a standard manual clutch.

The shifting process requires a short “learning curve” to become smooth as you work up and down through the gears with the semi-automatic transmission. Thanks to “Lazy Dog” for demonstrating this shifting process. Refer to Lazy Dog's full video here: [ Ссылка ]

As demonstrated here, the heel-toe shift lever can be used to feather the clutch, just like a standard handlebar clutch lever. Pressing the shift lever slightly – BEFORE it clicks into the next lower gear – opens the clutch. That is, the internal gears are momentarily disengaged. Likewise, holding the shift lever down keeps the clutch disengaged. Until you release the shift lever, the next gear is not meshed with the engine. You can rev the engine without engaging the transmission.

I hope that you agree that there are MANY advantages to the semi-automatic transmission on light motorcycles like the Honda CT125 and CSC Wolf 125. In both town and trail riding, the motorcycle cannot be stalled! New riders simply ride away! With a little practice, experienced riders will adapt to not using the hand clutch.

Understanding the operation of the semi-automatic clutch will also help eliminate one of the complaints about riding these small 125cc motorcycles offroad. There is simply ZERO power transferred to the drive chain until the engine reaches the mid-range in RPMs. You cannot crawl the bike at low RPMs – these small engines need to be ridden at higher RPMs and you need to shift accordingly.

IF you plan on riding demanding trails, especially with a heavy rider or a heavy touring load, consider lowering the gear ratio (which requires changing the front engine sprocket to the next SMALLER size and/or the rear-wheel drive sprocket to the next LARGER size.) Lower gearing will result in higher engine RPMs and faster gear engagement at lower speeds, along with delivering more torque for climbing hills or moving more weight.

Follow the link for the full article.

свернуть