bicycle drive train. Don't skimp on these pieces, because their failure can really hamper your ride.
Rear Derailleurs
Rear derailleurs not only allow you to change gears, but they also regulate the proper amount of slack in your chain.
* Shimano makes many of the most popular rear derailleur replacements. The SRAM Rival Road Bike Rear Derailleur is bulletproof with the precision of a hummingbird.
Front Derailleurs
Front derailleurs move the chain side to side on the front gears, if your bike has any. Front derailleurs are measured in terms of tooth capacity. Tooth capacity is a measurement of the difference between tooth sizes in your chainring.
* The is also a great device that is convertible between top pull and bottom pull.
