You are a bike enthusiast who is very keen to know more about every part of your favorite ride. Due to frequent usage of your bike, it might need a bit of service from time to time and you don’t want to bother your local mechanic to repair what you can do yourself. For this, you need some knowledge of important parts of your bike. One of the common queries which might arise is what is a rear derailleur on a bike? This article will deal with an overview of the rear derailleur and its usage.
What Is A Rear Derailleur On A Bike?
A rear derailleur is a tool fitted in the bike which is used for switching gears by shifting from one sprocket to another. This device is tasked with the responsibility of keeping the chain stretched to avoid slacking. They are fitted to the bike’s derailleur hanger with the help of a strong mounting bolt. The various operations of a rear derailleur are performed with the help of control switches and gears present in the handlebar of the bike. You can also control its operations by maneuvering the front frame of the bicycle.
How Rear Derailleur Works?
The rear derailleur is tasked with operating two types of pulleys fitted in an enclosure. These pulleys are known as Tension pulley and Guide pulley. These pulleys are responsible for two types of functions:
- While riding, when the gear shifting tool sends its signal to the rear derailleur, the tension pulley hauls backwards which increases the tension in the lower half of the chain to maintain stress and tautness throughout.
- The guide pulley is responsible for engaging the chain of the bike with the sprocket rim so that continuous contact is maintained while in motion.
The rear derailleur is also equipped with the clutch feature which is responsible for propagating equal stress and tension throughout the chain. The rear derailleur is an essential part which proves to be very helpful while riding the bike on a smooth slope or pushing the bike upwards through rough terrain. The gear should remain the same while riding uphill or downhill, whereas the tension in the chain and the operation of rear derailleur varies.
How Do You Repair Rear Derailleur?
- You can start by fitting the limit screws by pedaling forward to adjust the chain into the sprocket. The distance between the frame and the rear derailleur depends upon the clockwise and anticlockwise movement of the gear shifting tool.
- You should increase the stress and tension of the cable and reinforce the B-Tension screw so that the tension of the chain and cable is evenly adjusted.