How a motor without clutch change gear?

How a motor without clutch change gear? - 1

Added (1). How a motor without clutch change gear, i mean it needs to press the gear by foot but no clutch being used cause there were no clutch at all. Especially motor like Honda Dash or Yamaha Lagenda

Automaticly.

By using an automatic transmission that does not NEED a manually controlled clutch.

Motors do not change gears. Transmissions do. Look up planetary drives.

All engines have clutches. Whether they are the common type of clutch system on an automobile or they're automatic transmissions (which have hydraulic clutches - or torque converters as they are more commonly called). Other engines like the ones on mini-bikes have centrifugal clutches that spin weights out against a ring that transfers the engine's power to the drive train (or chain).

A friend of mine built a go-cart but wanted to be able to control power to the wheels by a belt. We used a belt tensioning method to transfer drive power to the wheels.

No matter what method you use, any engine (gasoline or diesel) has a clutch to engage or disengage the drive.

A CVT trans is good example of a VARIABLE RPM clutchless design matter of fact makers had to mimic the trans shifting feeling and sequence in cars with CVT trans to market them as multi geared trans There CVT means CONSTANT VARIABLE TRANSMISSION the variable is the gear basically its mimicked to make you think its shifting gears Thats the only thing that comes to my mind

We once drove a Toyota corolla with a bad clutch linkage for a week.

we simply matched the revs to the gears and turned off the engine at stop lights. Didn't damage the engine or the gearbox.