Chain guide

Although the front derailleur is designed for shifting, it also helps keep the chain from falling off when the bicycle goes over bumps. With some bicycles that are not equipped with a front derailleur, a chain guide (Figure 1) is specified to help keep the chain from falling off.

This section explains how to inspect, adjust, and lubricate a chain guide.

Read the Warning about Mechanical Work before performing any mechanical work on your bicycle.


Chain guide


Once a month, check the bearings of the lower roller of the chain guide. The roller should spin freely without any grinding noise. If the roller breaks this inspection, have it replaced by your retailer.

Every 3 months tighten the bolts to the torque specifications.


The chain guide is attached to the bottom bracket of the frame, so cannot be adjusted without special tools and training. If the chain guide needs adjustment or realignment, take your bicycle to your retailer for service.


The bearings of the chain guide are permanently sealed. Do not apply lubrication to the chain guide, as any lubrication or cleaning agents may penetrate the bearings and degrade the permanent grease.