Bontrager Race XXX Lite Introduction, Inspecting the crankset and bottom bracket

Introduction

The crankset- left and right crank arms and chainring(s) (Figure 1), and bottom bracket (the axle and bearings on which the crankset rotates)- allows your legs to pedal, transmit- ting power to the rear wheel.

This section explains how to inspect, adjust, lubricate your crankset and bottom bracket, and how to check carbon fiber parts for damage.

Cassette	Crank bolt
	Chain

Crankset

Pedal

Figure 2- Drivetrain parts

Inspecting the crankset and bottom bracket

Once a month, clean the chainrings and inspect them for damage. If any teeth are bent or broken, have the chainring replaced by your dealer. Note that on some chainrings, a few teeth have a special shape to enhance shifting.

Every 3 months inspect the crankset, check the bottom bracket adjustment, and tighten the bolts. These are maximum torque specifications:

•Crank bolts: 350 lb•in (40 N•m)

•Chainring bolts: 50-70 lb•in (5.7-7.9 N•m).

•Bottom bracket cups: 430-610 lb•in (48.6-68.9 N•m).

• Pedals: 350-380 lb•in (40.2-42.9 N•m)
	Figure 3 Tightening pedals
Turn the right pedal clockwise, but the left pedal counter-
clockwise (Figure 3).

To check the bottom bracket bearing adjustment

1.Lift the chain from the chainrings.

2.Rotate the crank so that one of the arms is parallel to the seat tube.

3.Put one hand on the crank arm and one hand on the seat tube, and attempt to move the crank arm laterally toward and away from the seat tube.

4.Spin the cranks.

If the crank feels or sounds loose, or if the motion stops abruptly or you hear a grinding noise coming from the bearings, the bearings need to be adjusted or re- greased by your dealer.

Adjusting the crankset and bottom bracket

The Race XXX Lite crankset offers ALS (Adjustable Length System). Refer to the Installation Instructions.

Adjustment of the bearings in the bottom bracket requires special tools and training. These services should only be performed by your dealer.

Lubricating the crankset and bottom bracket

Once a year, re-grease the bottom bracket bearings. Some bottom bracket bearings are permanently sealed and do not require yearly re-greasing. Re- greasing bearings requires special tools and training, so this should only be done by your dealer.

Whenever you are installing a threaded part, apply a small amount of bicycle grease to the threads, except for aluminum chainring bolts. With aluminum chainring bolts apply a drop of Loctite 222 to the threads.