Get to Know Your Motorcycle: Engine + Transmission
By Midwest Traction on August 29, 2017
Tips & Advice
Motorcycle engines work similarly to cars: there’s a head and cylinder block, pistons, and valve train. The spark plug ignites a mixture of air and fuel that’s pushed into the combustion chamber. This causes pistons to move, rotating the crankshaft, moving the rear wheel, and off you go!
Combustion chamber capacity is directly related to your engine’s power output. These range from 50-1500 cc’s. Lower capacity engines are slower, but offer greater fuel economy. For something in the middle that offers great fuel economy and more speed, try the 100-200 cc’s.
Firing on All Cylinders
Cylinder number and placement influence engine function and ride smoothness. Motorcycles max out at six cylinders per engine. Older models have two cylinders, with 45-degree pistons, but modern engines have four, which ride smoother and create more RPMs.
Transmission (drive system + clutch + gear set) controls the transfer of power between the rear wheel and the engine. Most motorcycles operate on a chain drive system, but shaft and belt systems are options, too. For chain drives, a chain connects the sprockets of the output shaft and the rear wheel.
The clutch allows you to engage and disengage the crankshaft power to the transmission without turning off the engine. It is comprised of a series of plates with springs innervating the transmission and crankshaft. When they press together, they connect your transmission and crankshaft to the springs and plates. While shifting gears, the clutch is first used to disconnect the crankshaft from the transmission, and after the gear is engaged the clutch again restores the connection.
Gear set is responsible for transmission control; complete stops are possible without cutting the engine. Shifting engages gears, which shift forks in the transmission. Regular bikes will have four or six gears, whereas small bikes can have a minimum of two gears.
Taking time to get to know how your bike functions helps to better understand how to care for it, why each component is important, and what to monitor for problems. Be safe, and enjoy your ride.