CHAPTER 9: BEARINGS AND DRIVE TRAIN
The drive train refers to the system of pedals and cranks, gears and chain, shifters and derailleurs, and wheels that propel the bicycle forward. Bearings, as discussed in the general mechanics chapter, page 106, are the little metal balls at the heart of any rotating system.
This chapter focuses on the most common type of drive train, the derailleur-based, multiple-cog, and chainring system, as discussed in the overview of the bicycle in Bicycle Anatomy, page 101. The general concepts here should apply to most common types of bicycle.
In addition, this chapter introduces bearing system overhaul, including working on hubs, bottom brackets, and headsets.