시마노 뒷드레일러 풀리 셋트 교체 따라하기. 풀리의 마모 체크부터 작동원리와 교체 작업까지 완전 정복하기

#RearDerailleurPullie #ShimanoPullieSet #PullieSetReplacement In this video, we will learn how to replace the rear derailleur pulley set on a mountain bike. The rear derailleur is a critical component of a bicycle's drivetrain for shifting; the tension pulley and guide pulley mesh together to rotate and smoothly guide the chain. However, because the chain is constantly engaged and rotating during riding, the gears on the pulleys gradually wear down. Initially, the gear teeth are square-shaped, but as wear becomes severe, they deform into sharp points, causing the chain to skip during shifting. While replacing the entire rear derailleur is expensive, purchasing and replacing the pulley set separately costs less than one-third of that amount. Although the process may seem a bit cumbersome, anyone can perform the replacement by carefully following along with the video.