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Shop the large inventory of cycling items and other bicycle rear derailleurs!

About Rear Derailleurs

For the uninitiated, a rear derailleur may sound like something out of a French restaurant, but it is certainly far from it. This bike part actually has a complex task. It's responsible for moving the chains in the back tire when you shift gears, transferring it between the different cassettes. When searching for new or used bike parts on eBay, make sure you purchase the right one for your bike. These parts have different ranges, capacities, and speeds, and one type of derailleur may not necessarily fit another. A 7-speed rear derailleur, for example, cannot fit on a 9-speed model, but as bike enthusiast, you probably know this. A derailleur for a Shimano XTR model might not fit on any other type or brand of bike, so finding out which one you need is crucial before you buy. For bikes that feel a little rickety or are simply not shifting properly, make sure you check the rear derailleur for any defects. If it is beyond repair, then it is definitely time for a new one. Even though you now know what this part is, a trip to the French restaurant might not be a bad idea anyway.