What is the reason for feeling something blocking when shifting into first gear?

[VanKendra]

Since first gear and reverse gear do not have synchronizers, you may feel something blocking when shifting into first gear or reverse while the vehicle is in motion. Here is some additional information: Synchronizers: Synchronizers come in various forms such as constant pressure type, inertial type, and self-energizing type. Currently, the inertial type synchronizer is widely used. It mainly consists of components like the engagement sleeve and synchronizer ring, and its characteristic is achieving synchronization through friction. Precautions: You should shift up one gear at a time and avoid skipping gears when shifting up, as skipping gears can cause discontinuous power in the car, leading to a stalling phenomenon. However, when shifting down, you can skip gears, and it is recommended to frequently perform downshifts by skipping gears.