How to Assemble a Bike Headset

A bicycle headset connects the front fork and steering assembly to the bicycle frame (references 1). Through the use of bearings contained within the headset, the fork and steering assembly are allowed to swivel independently of the frame. Modern bicycles commonly employ threadless headsets. Unlike traditional, “threaded” headsets, the individual threadless headset parts slide – rather than “thread” – onto the steering column. A headset is assembled initially with the fork removed from the bicycle frame.

Things You'll Need

• Headset race punch (as needed)
• Hammer (as needed)
• Head tube spacer (as needed)
• 5 mm Allen key
• 3 mm Allen key

Instructions

1. Remove the headset from the box or carton. A headset consists of several individual parts. Keep all parts together in the same order as you find them inside the box.

2. Take the bottom part of the headset, called the crown race, and fit it over the fork tube. The race must rest on the crown, or upper portion, of the fork with the tapered edge facing up. If the race does not slide onto the crown, see Step 3 for instructions – otherwise proceed to Step 4.

3. Fit a headset race punch over the fork tube until it comes into contact with the race. Use a hammer to hit the top of the punch, driving the race onto the crown of the fork.

4. Fit the first headset bearing cartridge into the lower head tube of the bicycle frame with the beveled edge facing up.

5. Press the first headset cone race against the base of the bearing cartridge. The race has a tapered edge that allows it to mesh with the bearing cartridge.

6. Slide the fork tube through the head tube of the bicycle frame, joining the crown race, cone race and bearing cartridge.

7. Place the second bearing cartridge over the fork tube until it comes to rest in the top of the bicycle frame head tube. Again, the beveled edge should face into the head tube.

8. Fit the second cone race onto the fork tube. The tapered edge will mesh with the upper bearing cartridge.

9. Place the plastic dust cap over the fork tube so that it covers the upper bearing cartridge.

10. Slide the stem portion of the handlebar assembly onto the fork tube. Check the gap between the top of the stem and the tip of the fork tube. Park Tool recommends 3 mm (references 2). To alter the gap, remove the handlebar assembly momentarily and place a spacer of adequate width onto the steering column.

11. Fit the headset top cap onto the tip of the fork tube. Thread the headset compression bolt through the opening at the center of the cap.

12. Hold the steering assembly so that the handlebar stem and front wheel are perfectly aligned. Use a 5 mm Allen key to tighten the compression bolt.

13. Use a 3 mm Allen key to tighten each of the bolts at the side of the handlebar stem.

Tips & Warnings

• Always double-check that all bolts have been tightened effectively. Improperly tightened bolts will result in loose steering, which is dangerous to operate.

References

• SheldonBrown: Bicycle Glossary
• ParkTool: Threadless Headset Service
• "Bicycle Maintenance & Repair for Road & Mountain Bikes;" Todd Downs; 2005