The connecting rods and big-end bearings of a motorcycle engine are central components that transfer the force from the pistons to the crankshaft. The connecting rod connects the piston to the crankshaft and converts the linear motion of the piston into the rotating motion of the crankshaft.
Connecting rod bearings ensure that the connecting rod can rotate around the crankshaft with little friction. These bearings have to withstand high loads and temperatures, which is why they should be regularly checked for wear.
A defective connecting rod bearing can cause serious engine damage, which is why proper lubrication and maintenance are essential.