How To Replace Your Own Headset

Your bike's headset insures that subtle aspects of your bike's steering geometry interact with your body movements. Any amount of friction is bad, and if the bearings become excessively pitted (as they often do) it is best to completely replace the headset. Don't worry; headset replacement is not expensive. You can send your bike to the bike shop and pay to have a professional mechanic do the job (a good idea), or you can read on and learn how you can install a headset at home (a great adventure).

Want to give it a shot? If you are moderately adept with tools and can find your way to the hardware store, you will soon find that replacing a headset is one of the simpler tasks especially now, with the advent of simple A-Headset-type thread less designs. Are you ready?

HOW TO TEST YOUR HEADSET
Stand beside your bike, grasp the front brake and rock the bike back and forth. As you do this, pinch your thumb and forefinger across the gap of the upper headset cups. If you feel any free play, the headset needs to be tightened (at least). Remove the front wheel, lift the bike so that it remains level (or clamp it into a work stand) and gently move the handlebar. There should be no friction through 90-degrees of movement. If you sense a grinding or indexing sensation inside the headset, it's probably pitted and needs to be replaced.

What you need, clockwise from the top: a new headset; 12 inches of  1-1/4" PVC tubing; an 8" long, 3/8" aluminum rod; an 8" long section of 3/4" threaded rod; two 3/4" nuts; two heavy-duty 3/4" fender washers; and one 6" chisel or a dull screwdriver.

Fork removal: Remove the stem and any spacers beneath it. Grab the frame and lift the front wheel off the ground. Use a plastic mallet to whack the steerer down an eighth of an inch. Put the wheel back down and the steerer will lift the A headset wedge up where it can be removed by hand.

Sherlock: Place the bearings, seal, and races down in the order they are removed to make reassembly easier. Clean the bearings, cups, races and seals in a non-toxic solvent. Inspect for missing bearings and pitted or broken races. Evidence of such warrants replacement (some quality headsets have non-serviceable, one-piece cartridge bearings).

Cup removal I: Firmly clamp the bike in a work stand by the seat post. Insert the aluminum rod through the top of the head tube and butt the end against the internal flange of the lower headset cup. Gently tap the cup out with alternating blows on opposite sides of the flange while working your way around in a circle.

Cup removal II: Remove the upper cup from underneath. Take care not to use too much force. If the frame is changing position in the stand, you are overdoing it.

Race removal: Inspect below the steerer race to find the opposed relief’s cut into the crown. Butt the steerer against a solid work bench and position the chisel at a relief so the flat is resting on the bottom of the race. Alternate sides and gently tap the race until it drops off its seat.

Install the lower race: Lightly grease the last inch of the steerer and the inner race. Drop the race over the steerer and partially press it into position by hand. Brace the underside of the crown on the edge of a bench. Use the 1-1/4" section of PVC and the plastic mallet to completely seat the race.

Home press: Grease the ends of the head tube and the cups. Evenly position one of the cups by hand. Insert the threaded rod and cap the cup and the top of the head tube with a fender washer and nut. Using a couple of wrenches, turn the nuts to press in the cup. Be sure that the cup doesn't cant to one side. If it does, tap it out and start over.

All the way: Repeat the same procedure, and press the opposite cup with the second washer driving against the seated cup. Any daylight between the cup and the ends of the head tube indicates that it isn't fully inserted. Smooth sailing: Thoroughly grease the bearings and races. Assemble the headset and install the stem. Firmly snug the A headset cap bolt and back off one quarter of a turn. Check for play in the headset and for smooth operation, then line up the stem with the wheel and tighten the stem. Recheck the headset adjustment and the stem clamp bolts and you are on your way.